Nyrstar Port Pirie Smelter Transformation Proposal Public Environmental Report
Appendix L: Environment and health feasibility study - Port Pirie Smelter Transformation Appendix L PERRelease 130705
5 July 2013
TABLE OF CONTENTS
Glossary ...... 5
1. Introduction ...... 7
2. Lead Sources ...... 9
2.1 Site History ...... 9
2.2 Overview of Smelter Sources ...... 10
2.3 Main Smelter Sources of Air Lead ...... 11
3. Solution for Reducing Emissions ...... 16
3.1 Technology Transformation ...... 16
3.2 Enclosed Bath Smelting – Process Review and Comparison ...... 17
3.3 Sequence of Process Improvements ...... 19
3.3.1 Sinter Plant Replacement with Enclosed Bath Smelting ...... 19
3.3.2 Recovery of Pit Materials ...... 19
3.3.3 Concentrate and Other Feed Handling Improvements ...... 20
3.3.4 Ventilation Improvements...... 20
3.3.5 Slag Fuming Process and Emission Improvements ...... 21
3.4 Emissions Control ...... 21
3.4.1 Process Off-gas ...... 21
3.4.2 Hygiene Ventilation ...... 22
4. Observations of Best Available Technology...... 23
4.1 Umicore (Hoboken, Belgium) ...... 23
4.2 Teck Resources (Trail, Canada) ...... 27
Appendix L
1 1 . 3 9 . 3 7 .. 56 .. ... 48 ...... 39 ...... 44 ...... 55 ...... 44 ...... 34 ...... 58 ...... 50 ...... 39 ...... 32 ...... 55 ...... 40 ...... ...... 46 ...... 57 ...... 40 ...... 57 ...... 35 ...... 34 ...... e at Port Pirie Port at e ...... 4 ...... 58 ...... Exposure ...... ...... ...... Lead Exposure Pathways Lead Metabolism Lead Reservoirs Lead Sources Factors Lead Influencing Blood Children’s Levels Blood Lead Blood Recommendations
5 July 2013 5 July Outcomes, Management & Treatment Treatment of Lead & Outcomes,Exposure Management ...... A Distributional Approach Reliability of Outcomes of Reliability of Exposure and Measures Lead Kinetics Health Outcomes Associated with Health Lead Outcomes Exposure with Associated Environmental Justice ...... for Lead Exposure Children Historical Perspective Introduction Spatial Variation in Air Lead Spatial Concentrations Variation Lead in Air Trends Historical Air Lead Lead Deposition Rates Conclusion rePost-TransformationConclusion Performanc Likley
Framework for Managing for Lead Framework Managing Exposure ...... Relating Lead Lead Blood Pirie and Air in Port 6.3.5 6.3.6 6.3.4 6.3.3 6.3.2 6.3.1 ...... Lead Exposure in Port Pirie Air Quality Data For Port Pirie Port For Data Quality Air 8.3 8.4 8.5 8.6 8.1 8.2 6.3 6.2 6.1 5.1 5.2 5.3 4.3
8. 7. 6.
5.
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8.7 Lead Impacts on Biochemistry & Intelligence ...... 59
8.8 The Historical Background in Port Pirie ...... 60
8.9 A Distributional Approach and Subsequent Management ...... 61
9. Post-transformation Performance ...... 63
9.1 Introduction ...... 63
9.2 Likely Performance Post-Transformation ...... 63
9.3 Targeted Lead Abatement Program ...... 66
9.4 Likely Performance Compared with International Standards ...... 67
10. Conclusion ...... 69
11. References ...... 71
Appendix L yrstar Port Pirie Transformation Project) Project) Transformation Pirie Port yrstar ch Organisation ch Organisation able tre (μg/dL) (μg/dL) tre of lead particulates in the air, units – units air, the in particulates lead of rvey ssessment n the former USSR. The name is a Russian Russian a is name The USSR. former the n ombustion lance, developed jointly by Mount ) 3 acronym‘flash-cyclone-oxygen-electric-smelting for ’ Isa Mines and CSIRO CSIRO and Isa Mines micrograms per cubic metre (µg/m metre cubic per micrograms 5 July 2013 5 July NEPM NEPM Measure Protection National Environmental NHANES Su Examination Nutrition and Health National KIVCET KIVCET i developed furnace flash-smelting of type a BPb BPb BAT (μg/dL) tre decili per micrograms – units level, lead Blood BATEA Best availabletechnology achiev economically technology available Best BLL CAPEX decili per micrograms – units level, lead Blood expenditure Capital CDC CSIRO ) (USA Prevention and Control Disease for Centers Resear Industrial and Scientific Commonwealth Cu EBS Copper EHWP Smelting Bath Enclosed Environment and HealthWorking Party (of the N EIP ESP Program Improvement Environmental IQ precipitator Electrostatic ISASMELT c submerged a with process smelting bath a Intelligent quotient
GLOSSARY ACTRA A Risk and Toxicology of College Australasian ADHD ADHD disorder hyperactivity deficit Attention APb concentration the i.e. (concentration, lead Air
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NHMRC National Health and Medical Research Council
NTP National Toxicology Program (USA)
ODTF Olympic Dam Task Force
Pb Lead
Pb24-hr Air lead average concentrations averaged over 24 hours
PM10 Particulate matter in the atmosphere that has an aerodynamic diameter of 10 µm (micrometres) or less
QSL a direct smelting technology. The name is an acronym for the developers Queneau, Schuhmann, and the company Lurgi
SES Socio-economic status
SKM Sinclair Knight Merz, an engineering consulting company
SKS an enclosed bath smelting technology, an acronym for the Shuikoushan company that developed the process
TEOM Tapered Element Oscillating Microbalance (instrument for measuring particulate mass)
THEC Trail Health and Environment Committee
TSL Top submerged lance
TSP Total suspended particles
WHB Waste heat boiler
WHO World Health Organisation
Zn Zinc
Appendix L
tection of children. of children. tection otection of children of Port Pirie; and and Pirie; Port of children of otection to reduce the emissions; emissions; the reduce to ns; t Howell (Nyrstar) and includes Dr Mark Mark Dr includes and (Nyrstar) t Howell ided adviceon: the EHWP has been able to make use of of use make to able been has EHWP the the Environment & Health Working Party Party Working & Health Environment the ovide assistance. A Joint Steering Committee Committee Steering Joint A assistance. ovide nt and determinationof best available August 2012 leaving the EHWP only three three only EHWP the leaving 2012 August head with in-principlesupport for investment whether the project was technically and and technically was project the whether imon (SA Health) has contributed to the report. report. the to contributed has Health) (SA imon tunately some relevant investigations investigations relevant some tunately short time-frame it was not possible to conduct conduct to possible not was it time-frame short nvironmental Consultant) and DrKevin Buckett an College of Toxicology and Risk Assessment) Assessment) Risk and Toxicology of College an ce. ons, the most important of which (due 31 March March 31 (due which of important most the ons, ty to undertake this program with its own own its with program this undertake to ty ment Improvement Program (EIP). The program program The (EIP). Program Improvement ment reduce lead emissions from its smelter. EPA smelter. from its emissions lead reduce ons, including including identification,ons, feasibility of this complexity would take 12 to 18 months and and months 18 to 12 take would complexity of this lead sources by CSIRO using pollution backtracking pollution using CSIRO by sources lead tion. the Investigative EIP, the Steering Committee Committee Steering the EIP, Investigative the ary form, by October/November 2012. This would would This 2012. October/November by form, ary 5 July 2013 5 July Evaluation of the adequacy of these outcomes for pr for outcomes these of adequacy the of Evaluation Recommendations on the best strategy for future pro future for strategy best the on Recommendations The likelyoutcomes forair lead and blood lead; The capability of alternative smelting technologies smelting of alternative capability The Evaluation of the likely sources of smelter emissio of smelter sources likely the of Evaluation
• • • • • INTRODUCTION
these. This includes the investigation of the major the of investigation the includes This these. detailed investigations. Normally an investigation investigation an Normally investigations. detailed and underway already were by Nyrstar) (commissioned (Hibberd 2012). enable the Steering Committee parties to determine determine to parties Committee Steering the enable in Committee Steering the by made was request This a such with Obviously report. its prepare to months so an alternativeapproach had to be developed. For Whilemostof willadvicethis also be required for prelimin in least at provided, be it that requested environmentallyviable and whether they should goa investiga of feasibility stage next the to move and was formed and a numberof subcommittees, including advi specialist provide to established were (EHWP), resources and approachedthe State Governmentto pr Mat and (ODTF) Thomas Rob A/Prof by led is EHWP The E Nyrstar (Internal Gilbert (CSIRO), Andrew Hibberd assessment, technical assessment, economic assessme economic assessment, technical assessment, (BATEA). achievable economically technology capaci the have not does it that recognised Nyrstar (Australasi Moore R. Michael Professor Health). (SA requires Nyrstar to conduct a number of investigati a number conduct to Nyrstar requires opti reduction lead on report a provide to is 2013) S David Dr and Party, Working the by contracted was requires Nyrstar to submit an Investigative Environ Investigative an submit to Nyrstar requires prov EHWP the that requested Committee Steering The 1. to EPA the by directed been has Pirie Port Nyrstar
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However, in the absence of a comprehensive emission inventory and the complexity of the relationship between air lead and blood lead, this report by the EHWP relies largely on analysis of available data, observations of experience from overseas smelters, and expert judgement to develop its findings and recommendations.
Consequently, while the EHWP considers that the information is accurate enough for the Steering Committee to make its in-principle decision, it is envisaged that the analysis and predictions presented in this report will be refined during the feasibility study following the in-principle decision.
Appendix L
. ant y to ed to ‘Ten for Them’, with a focus on on focus a with Them’, for to ‘Ten ed 05, when Nyrstar (at that time Zinifex) Zinifex) time that (at Nyrstar when 05, a unique way of addressing the issue. The idea idea The issue. the addressing of way unique a findings from a backtracking study that that study backtracking a from findings ment of Health, the Port Pirie Regional Council, Council, Regional Pirie Port the Health, of ment create greater ownership by employees. employees. by ownership greater create ilver and 36,000 troy ouncesof gold per annum. issions and raising environmental awareness awareness environmental raising and issions th Australia, approximately 230 km north of of north km 230 approximately Australia, th smelting industry by-products. The Port Pirie Pirie Port The by-products. industry smelting a precious metals refinery, a copper plant and a and copper plant a metals refinery, precious a nt operation for more than 120 years. There is an an is There years. 120 than more for operation nt ectively to achieve the required reduction in lead lead in reduction required the achieve to ectively ges as it is a very old site that has been in const in been has that site old very a is it as ges 195,000 tonnes of lead, 30,000 tonnes of zinc, of zinc, tonnes 30,000 of lead, tonnes 195,000 possible. possible. smelter at Port Pirie, before giving an overview of overview an giving before Pirie, Port at smelter multi-metals recovery facilitywith the flexibilit oup most at risk of lead exposure. The ‘Ten by 10‘ 10‘ by ‘Ten The exposure. of lead risk at most oup Piriecommunity have been a standinglong issue. ld sinteringld technology which generatesairborne rd thi the and facilities smelting lead primary argest 5 July 2013 5 July SITE HISTORY LEAD SOURCES LEAD SOURCES
themain smelter sources,and then summarisingkey data meteorological and quality air using lead air Pirie’s Port of sources smelter main the identified Sou in Gulf Spencer of shore eastern the on Located consta in been has smelter Pirie Port the Adelaide, by dispatched products final with received, are concentrates where facility port dedicated adjacent rail. road and l world’s the of one is site Pirie Port Nyrstar The 2.1 2. the of background brief a with starts section This integrated is an plant The producer. largest silver
operation for over 120 years. It utilises largely o largely It utilises 120 years. over for operation em reducing on focus constant a is There emissions. zinc plant. It produces a range of metals including metals of range a produces It plant. zinc s of ounces troy 18,500,000 copper, of tonnes 4,000 challen of current number a has site Pirie Port The through training and changed work practices to help process a wide range of lead rich concentrates and and concentrates rich of lead wide range a process refinery, and smelter a lead incorporates operation Port the in children in levels lead blood Elevated 20 in commenced issue the on action recent most The Depart SA the – stakeholders key several approached propose to Authority Protection Environment the and involved key partners joining together to work coll work to together joining partners key involved gr age the of age, years 4 under children in levels program commenced 2005.in From 2011the namechang reducing blood lead levels in children to as low as low as to children in levels lead blood reducing
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2.2 OVERVIEW OF SMELTER SOURCES
In 1999, a basic fugitive particulate emissions study was carried out by Sinclair Knight Merz (SKM 1999). This study consisted of a quantitative assessment of the emissions from the Sinter Plant, Blast Furnace, Slag Fumer, and KDR area. Air dispersion modelling was then used to determine offsite impacts and estimate the contribution from the various sources. The results of this study were used to determine the actual tonnages of lead and other metals emitted by source from the smelter and also the relative contributions to concentrations at particular receptors. The combined effects of the meteorology, the source characteristics, and their locations relative to the receptor affect their relative contributions at the receptor compared with the relative source emission strengths.
Since this time, significant emissions reduction work has been carried out to reduce emissions from the Blast Furnace. The basis of this has been the installation of a Blast Furnace Top Enclosure and associated fume capture system. It is estimated that this improvement has reduced the Blast Furnace Top emissions by about 75%. Based on this improvement since the SKM study and NPI estimates showing that other point and area sources contribute about 20% of the total lead emissions, it is estimated that the contributions to Port Pirie air lead are currently approximately 50% from the Sinter Plant and Blast Furnace and approximately 30% from the Slag Fumer.
Since 2005, Nyrstar has made a significant commitment to the community through the ‘Ten by 10’ and ‘Ten for Them’ programs. Approximately $50 M has been spent on site and in the community on emission reduction and exposure reduction initiatives, as part of these programs.
It is important to note that with the replacement of the Sinter Plant planned as the major capital expenditure of the Transformation Project, the Blast Furnace feed quality will improve significantly, and the demands on the smelting draughting/baghouse system will be significantly reduced. As a result, it is expected that the Blast Furnace will operate with fewer plant-upset conditions (and hence reduce the potential for emissions) and will make use of the improved availability of the draughting system. It is also important to note that the Sinter Plant throughput of materials is of the order of one million tonnes per annum, and of that, approximately 50% is in constant recycle being transported to and from the pit. This means that much of the intermediates material handling and storage on the Port Pirie smelting site (and thus sources of lead dust) is as a direct consequence of this single unit metallurgical process.
For these reasons, it is considered that the Sinter Plant and the associated activities account for the main proportion of lead emissions from the site and that the Transformation Project will lead to reductions of more than 50% in lead dust emissions from the smelter site.
Appendix L
needs to needs four nges. The length
ite for the four years from 2007 – 2011. Note Note 2011. – 2007 from years four the for ite of the winds are from the south-south-east south-south-east the from are winds the of the south-south-west, and very fewwinds from s and backtracking analysis to identify the the identify to analysis backtracking and s urces responsible for the majority of days with with of days majority the for responsible urces r variation in the wind roses during this four year four this during roses wind the in variation r n below,the region identifiedwas that occupied by y wind direction, with colour bands showing wind ra nd from that direction. from the well-sited Boat Ramp wind sensor for the the for sensor wind Ramp Boat well-sited the from 1
5 July 2013 5 July Port Pirie wind rose as measured at the Boat Ramp s Boat at the measured as rose wind Pirie Port MAIN SMELTER MAIN LEADSOURCES AIR OF
A wind rose shows the frequency of winds plotted b the wind sensor indicated that a correction of +3° +3° of that a correction indicated wind the sensor of alignment the of 2012) (Dec check that a recent directions. wind to these applied be
1 Figure 1. 2.3 A study by CSIRO(Hibberd 2012) used pollution rose region of the smelter most likely to contain the so the contain to likely most smelter of the region the sinter plant and blast furnace. rose wind Pirie Port the 1 shows Figure high air lead concentrations in Port Pirie. As show As Pirie. Port in concentrations lead air high of each band is proportional to the frequency of wi to frequency the is proportional band of each years from1 November 2007to 31 October 2011.Most and north-north-west, with less frequentwinds from year-to-yea little was There sector. north-east the period.
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Figure 2 shows the locations of the high volume air samplers in Port Pirie, which measure 24-hour 2 average air lead concentrations each day. Continuous 10-minute average PM10 measurements using a TEOM instrument3 are also made at several sites – Dental Clinic, Boat Ramp, and the Terrace.
Figure 2. Location of the high volume air samplers in Port Pirie. The Nyrstar smelter is located north of the Dental Clinic site.
2 PM10 is particulate matter in the atmosphere that has an aerodynamic diameter of 10 µm (micrometres) or less. It is one of the six criteria pollutants for which there are national standards in Australia (see www.environment.gov.au/atmosphere/airquality/publications/standards.html
3 A Tapered Element Oscillating Microbalance, an instrument for measuring particulate mass.
Appendix L
at the Boat Boat the at 3
ent of the Dental the of ent ns (see (Hibberd concentrations were were concentrations ) occur for wind wind for occur ) 3 > 2 µg/m > 2 24-hr b concentrations versus 1-hour average 1-hourwind average versus b concentrations data at the Dental Clinic and Boat Ramp sites sites Ramp Boat and Clinic Dental the data at h air lead days (defined here as 24-hour 24-hour as here (defined air lead days h ng to the main sources being in this octant. octant. this in being sources main the to ng tion rose (Figure 3) shows that on high lead days, days, lead high on that 3) shows (Figure rose tion so providedso the bestopportunity for triangulation e data from approximately 10% of days over the the over days of 10% approximately from e data n concentrations at each wind direction. It is an an is It direction. wind each at concentrations n at the Dental Clinic and Pb and Clinic Dental the at eeds to be applied to these wind directions. to these applied to be eeds 3 . Note that a recent check (Dec 2012) of alignm the 2012) (Dec check that a recent Note . 3 > 10 µg/m > 10 concentrations (yellow and red, >50 µg/m >50 red, and (yellow concentrations data as a surrogate for relative lead concentratio lead for relative surrogate data as a 10 10 24-hr data were available from these sites and the lead lead the and sites these from available were data > 10 > µg/m 10 24-hr 5 July 2013 5 July Pollution rose at Dental Clinic of 1-hour average P average 1-hour of at Dental Clinic rose Pollution direction for days when Pb when days for direction to pinpoint the lead sources. hig on data from generated were roses pollution The Pb lead concentrations average well above detection thresholds. These two sites al sites two These thresholds. detection above well Ramp) using1-hour average PM directions between northand north-easterly, pointi
Figure 3. bution of distri wind the speeds depicts at rose eachwind direction, wind a that way a same the In of pollutio distribution the depicts rose pollution easily understood pollution means highest the of with showing which associated wind are directions from generated were roses Pollution concentrations. because lead, wind andPM Clinic wind sensor shows that a correction of +8° n +8° of that a correction sensor shows wind Clinic 2012) for more details). The pollution roses includ roses pollution The details). more for 2012) pollu Clinic Dental The 2008-2011. period year four almost two-thirds of the high PM high of the two-thirds almost
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Figure 4. Pollution rose at Boat Ramp of 1-hour average Pb concentrations versus 1-hour average wind 3 direction for days when Pb24-hr > 2 µg/m . Note that a recent check (Dec 2012) of the alignment of the Boat Ramp wind sensor show, shows that a correction of +3° needs to be applied to these wind directions.
An extract of these data plotted at the top right-hand side of the figure shows the peak at 22.5° and with the other data well fitted by a Gaussian distribution with the highest values between 10° and 30°. By comparison, at the Boat Ramp site, Figure 4 shows a strong clustering of the data on high lead days at wind directions around the wind direction of 335° with the highest values between 330° and 340°.
The main wind directions corresponding to high PM10 concentrations on high air lead days are shown overlaid on a map of Port Pirie in Figure 5. (Note that the wind direction corrections noted in the captions to Figure 3 and Figure 4 have been applied in Figure 5.) The intersection of the lines pinpoints the main emission sources as being in the immediate vicinity of the Sinter Plant. This result confirms the conclusion of Section 2.2 that the Sinter Plant (and associated activities) is the dominant source compared to the Slag Fumer and Pit areas.
Appendix L
ared to ared ons for for ons y of the the y of
concentrations on high on high concentrations 10 cipal wind directions identified in pollution roses pollution identified in directions wind cipal e wind direction corrections described in capti the described corrections direction wind e ysis shows that these are the dominant sources comp sources dominant the are shows that these ysis pinpoints the main sources as being in the vicinit being the in as sources main the pinpoints 5 July 2013 5 July Map of Port Pirie and the smelter showing the prin the showing and smelter the Pirie Port Map of and Figure 4 have been applied here. here. applied been have 4 Figure and
Sinter Plant (SP) and Blast Furnace (BF). This anal This (BF). Furnace and Blast (SP) Plant Sinter that th Note areas. Pit and the (SF) Fumer Slag the
Figure 5. as being associated with high PM high with being associated as figures) (previous Ramp and Boat Dental Clinic from
air lead days. The intersection of the yellow lines yellow the of intersection The days. lead air Figure 3
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3. SOLUTION FOR REDUCING EMISSIONS
3.1 TECHNOLOGY TRANSFORMATION
The key premise of the Port Pirie redevelopment project is to replace the aged sinter plant with modern enclosed bath smelting technology, thereby eliminating the major source of fine oxide and other Pb-based emissions to air. The updraught sinter machine was commissioned in 1956 and although considered best available technology at that time, this no longer the case. Updraught sintering involves a high temperature, pressure forced process, coupled with a suction of Pb laden off gasses to gas cleaning and sulphur capture. The plant consists of numerous open conveyors and dry crushing rolls that give rise to substantial fugitive dust sources due to the physical inability to draft all process stages. The process itself uses approximately 50% recycled materials (predominately sinter), which is comprised chiefly of Pb oxides. As a consequence, the numerous dry handled materials over a geographically large footprint, combined with a high temperature process that is inherently difficult to control, lead to it being the largest source of Pb in air emissions from the site. Section 2.3 summarises the key findings of a separate report by CSIRO (Hibberd 2012), which confirms the source apportionment conclusions summarised above.
A secondary but important source of emissions arises from the blast furnace when treating off-grade or cold sinter. As sinter physically degrades with time and loses its mechanical properties, the blast furnace performance also erodes, leading to characteristic emission events (‘furnace blowholes’). These events result in localised high intensity gas eruptions from the main furnace charge and are difficult to fully capture, despite the ventilation hood fitted over the furnace structure. A move away from sinter to a uniform slag, consistent in physical and chemical properties is expected to translate into consistent blast furnace operating performance, thereby reducing or eliminating the blowhole characteristics. Finally, replacement of the aged sinter plant with modern enclosed bath smelting technology (EBS) will reduce the volume of blast furnace feed, since a proportion of the EBS output is lead bullion, which bypasses the blast furnace. As a result, the blast furnace operational intensity will be moderated, further improving process stability and fume capture.
Other sources of Pb materials that contribute to the Pb in air profile include the secondary materials handling area ‘the pit’, the slag fuming plant and concentrate handling system. It must be noted that the bioavailability of each material is heavily dependent on chemical composition and particle size, with very fine oxides being most bioavailable and coarse sulphide concentrates being least bioavailable.
Appendix L
g SON VCET technology technology VCET ny and Korea), one using ISASMELT (Belgium) (Belgium) ISASMELT using one Korea), and ny and reductionstages in the onevessel. The , both Outotec® Ausmelt and ISASMELT ISASMELT and Ausmelt Outotec® both , nner thatemissions are minimised and or belts through feed ports into the horizontal, horizontal, the into ports feed through belts or ssel. The input and output ports of the vessel, vessel, the of ports output and input The ssel. n a commercial scale to primary lead smelting smelting lead primary to scale a commercial n nd fifteen using SKS technologies (1 in Mongolia, Mongolia, in (1 technologies SKS using fifteen nd nt (early 2000s). Globally, at present there is one is there present at Globally, 2000s). (early nt such that emissions are small in quantity and and quantity in small are emissions that such second compartmentwhere heat is applied by on time, the slag separates from the bullion to to bullion the from separates slag the time, on lting shaft. As this coke sinks through the slag, slag, the through sinks coke this As shaft. lting agents and removal of molten and gaseous gaseous and molten of removal and agents S) processes is that the smelting reactions are are reactions smelting the that is processes S) s at the bottom of the reactor. Due to the slight slight the to Due reactor. of the bottom the at s rate is converted to lead oxide in the flash flash the in oxide lead to converted is rate injection devices (lances or tuyeres) during during tuyeres) or (lances devices injection lished sintering – blast furnace route. Enclosed Enclosed route. furnace blast – sintering lished es and flux agents form a semi-fused slag which which slag semi-fused a form agents flux and es tuyers clear of the slag for tuyere maintenance or maintenance tuyere for slag the of clear tuyers tion(1 Mongolia,in 1 in India,13 in China). he reduction zonewhere pulverised coal is added ture of bullion and slag then flows under a a under flows then slag and of bullion ture ad which then flows back to the oxidation zone. The zone. oxidation the to back flows then which ad d ofd the oxidation zone and primary slag,containin y used for treating secondary lead materials. lead secondary y for treating used process (Boliden in Sweden), two smelters using KI using smelters two Sweden), in (Boliden process 4 5 July 2013 5 July ENCLOSED BATH SMELTING ENCLOSED BATH – REVIEWPROCESS COMPARI AND
The Kaldo process is a batch process, and is mainl process, and is a batch process Kaldo The separation wall from the first compartment into the into compartment first the from wall separation retenti With additional electrodes. carbon ofmeans the leadoxide is reduced to lead bullion. Thismix collects under a layer of coarse coke below the sme the below coke of coarse layer a under collects smelting shaft and a mixture of lead-zinc-iron oxid lead-zinc-iron of mixture a and shaft smelting vessel can be rotated through about 90° to lift the to lift 90° about through rotated be can vessel replacement. concent the in sulphide lead process, KIVCET the In to reduce the lead oxide in the slag to metallic le metallic to slag the in oxide lead the to reduce residual leadoxide, flows counter-currently intot 14 China),in with a furtherfifteen underconstruc (Canada and China), two using QSL technology(Germa and one using Ausmelt technology (both in China), a oxidation the combine processes KIVCET and QSL The In them. between slag or solid molten of transfer a with vessels two require processes SKS and TSL convey from fed is charge premixed process, QSL the tuyere through blown is Oxygen reactor. cylindrical en front the to flows bullion lead the inclination,
4 3.2 (EB smelting bath enclosed of feature essential The ve enclosed an within state molten the in performed required to enable addition of raw materials and re and materials of raw addition enable to required Kaldo the using smelter products, are sealed and/or ‘protected’ in mannera offtake gas the with vessel the in pressure ative neg maintaining by achieved is This controlled. are of changes Similarly, pollutants. remove to treated ma a such in performed be to able be must operation controlled during the change-over period. Globally, most lead smelted is using thewellestab bath smelting technologies that have been appliedo (TSL) smelting Lance Submerged Top QSL, KIVCET, are variants, and SKS. SKS is the most recent developme recent most the is SKS SKS. and variants,
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form two layers. From this compartment, slag is tapped to the slag furnace and bullion is tapped for transfer to the Pb refinery.
In the Outotec® Ausmelt and ISASMELT processes, air, oxygen and fuel/reductant (typically pulverised coal) are injected into the molten slag bath contained in a vertically mounted, cylindrical reactor, by means of a vertically suspended lance. Oxygen enrichment may be used to reduce off-gas volumes and minimise fuel requirements. The Outotec® Ausmelt lead process may include smelting, slag reduction and fuming stages; however, the fuming stage is only necessary if zinc recovery is required. For smaller scale projects each stage (smelt, slag reduction and fuming if necessary) can be conducted as a batch process in a single furnace. To increase production, two furnaces, one performing oxidation and the other reduction, can be employed. Where it has been employed on a large scale, the ISASMELT process has been configured with a single vessel oxidation process operating continuously to produce a molten high lead slag which is tapped, cast and fed as lump to a blast furnace as a replacement for lead sinter.
The SKS process has some similarities to the QSL process in that the reactor is a horizontal, cylindrical vessel with bottom tuyeres. However, as with the Outotec® Ausmelt and ISASMELT processes, the oxidation and a reduction stages are performed in separate reactors. The reduction stage can be performed in a blast furnace, using solidified, lumpy the slag from the oxidation stage, or it can be performed in second bottom-blown reactor (with electrical heating by electrodes) by directly transferring the molten slag from the first stage.
Like the other processes, the SKS reactor is a closed vessel, except for the ports provided for feeding raw materials and the gas offtake for removing gaseous products. It is a bath smelting process which involves injection of gases (and solid particles) into a molten bath to produce conditions that result in rapid reaction through the high heat and mass transfer rates induced by the turbulent conditions in the bath. Like the other processes (to varying degrees), there is a quiescent zone in the reactor to allow lead bullion and slag to separate into layers so they can be removed separately.
In all the technologies (except KIVCET), the lance or tuyeres need to be replaced periodically. This may range from once every several weeks (e.g., Outotec® Ausmelt and ISASMELT processes) to several months, according to the technology (30 - 60 days has been quoted for the SKS process). In all the technologies, this is possible to perform ‘on-the-run’ by temporarily taking the reactor offline. This involves stopping air/oxygen blowing and feeding of raw materials while the lance/tuyere is replaced without having to empty the reactor of the molten bath. The process can then easily be restarted by recommencing air/oxygen injection and feeding of the raw materials. In the case of the QSL and SKS reactors, the reaction vessel is rotated along its axis to expose the lance/tuyeres above the molten bath to enable them to be replaced while the molten bath is in place while for the Outotec® Ausmelt and ISASMELT processes, the lance is simply raised vertically to remove it from the fixed reaction vessel.
Appendix L
lag e G rces using air lead data data air lead using rces g furnaceg remediation of pit footprint. footprint. of pit remediation replacing the plant with a modern EBS EBS modern a with plant the replacing control. Engineering options will be assessed r a ventilation hood to capture any Pb fume fume Pb any capture to hood ventilation a r her residues to be thinly coated over particles of particles over coated thinly be to residues her echnology) fume handling and hygiene ring ring feeds have no fuelvalue), thesite requires ximately 50% recycled materials and results in a a in results and materials recycled 50% ximately m, since the slag from the first stage EBS furnace furnace EBS stage first the from slag the since m, ions, but also substantially reduces blast furnace furnace blast reduces substantially also but ions, d ferrous metals and allow complete enclosure, enclosure, complete allow metals and ferrous d the present sinter feed. Automated blast furnace furnace blast Automated feed. sinter present the process. The general sequence of continuous ssed in the first stage EBS to produce a Pb bullion Pb a to produce EBS stage first the in ssed a zinc rich slag phase as is currently the case. S case. the currently is as phase slag rich zinc a eplacementof the sinter plant and improvements is a physical limit to the proportion of proportion the to limit physical a is esidues (mainly paragoethite from Hobart and lead and Hobart from paragoethite (mainly esidues a solid mass(‘sintered’) thein sintermachine. adles under controlled conditions and transferred sting into finished products.The slag phase will b 5 July 2013 5 July SINTER PLANT REPLACEMENT WITH ENCLOSED BATH SMELTIN Slag fuming improvements- based on pinpointing sou Hygiene air improvements improvements air Hygiene Concentrate handling improvements Recovery of pit materials, followed by closure and and closure by followed materials, of pit Recovery Sinter plant replacement with enclosed bath smeltin bath enclosed with replacement plant Sinter PITRECOVERY OF MATERIALS SEQUENCE OF PROCESSOF SEQUENCE IMPROVEMENTS
• • • • •
3.3.1 3.3.2 high circulating load of intermediates. Since there Since ofintermediates. load circulating high intermediates thatcan besintered (non-sulphur bea existing sinter, before being thermally fused into into fused thermally being before sinter, existing Consequently, sintermachine feedconsists of appro The sinter processrequires new concentrates andot sulphates from Nyrstar zinc smelters) will be proce be will smelters) zinc Nyrstar from sulphates ca and purification for refinery Pb existing the to The general sequence of improvements commences with commences improvements of sequence general The furnace system, complete with BAT (Best Available T Available (Best BAT with complete system, furnace r plant zinc and concentrates of mix A ventilation. and a slag phase. The bullion will betapped into l blast existing the to charging for 'bricks' into e machin casting line straight conventional a on cast and bullion Pb to reduced be will it where furnace, unde performed be will furnace EBS the from casting molten. is slag the while released is that emiss plant sinter the eliminates EBS to change The emissionsthrough improved process performance and syste feed furnace blast the automating to consider than volume charge lower physically a present will 3.3 r involves Pirie Port at transformation process The is thus: Pirie Port at improvements an base of variety a in known well are systems feed system. the EBS similar to in other sources of Pb-based emissions in a staged a staged emissions in Pb-based of sources other in
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surge capacity for the range of Pb, Zn and Cu based plant residues that arise in the normal course of operations. Storage is presently in a 30 hectare open area, with materials segregated by origin and generally wetted with sprays or proprietary dust suppressants. Despite these limited controls, wind mobilisation of dusts is an everyday problem. Slurried materials are also tracked via vehicle tyres around roadways and when dried, represent a physically large and persistent source for dust emissions.
The application of EBS technology allows all pit materials to be substantially eliminated. EBS is a ‘single pass’ system that does not require recycled feed components to carry the new concentrates (unlike the sinter process). As a consequence, it is expected the approximately 20,000 tonnes of intermediate residues currently stored in the pit, including all of the Pb oxide bearing sinter material will be completely consumed within the first full operating year. The closure of the pit will allow for land remediation that will not only eliminate this as a source of wind borne Pb, but also eliminate the source of the slurry material that is carried on vehicle tyres and deposited on the site roadways.
3.3.3 CONCENTRATE AND OTHER FEED HANDLING IMPROVEMENTS
While concentrates are known to be a minor source of Pb emissions on high wind days, the simplified plant layout of an EBS facility will allow a smaller number of conveyor belts used for feed transportation. This lends itself then to simple but effective designs for full enclosure with appropriate hygiene ventilation. Such designs are standard practice in many industries and were observed specifically at the Umicore (Hoboken) and Teck Resources (Trail) multi-metal smelters.
Feed blending is allowed for in the modernised plant design, such that all feed materials are either stored in covered bunkers or metered feed bins with appropriate dust capture.
3.3.4 VENTILATION IMPROVEMENTS
Implementation of EBS relieves a significant load from the existing Pb plant bag house system, since the sinter plant is no longer required to be serviced from this facility. Volume and flow calculations indicate approximately 40% of the existing baghouse capacity will be freed up by decommissioning the sinter plant. This figure includes the volume necessary to fully draught the EBS furnace charge ports, bullion tap and slag tap / casting conveyor. The EBS furnace does not require the large volume draughting required for the sinter plant, since sulphur rich off-gasses are treated via the gas cleaning and acid plant. The smaller volume of hygiene drafting air around the furnace feed ports, slag tap and bullion hearth are minor considerations in terms of overall volume and well within the capabilities of the existing system. Surplus baghouse capacity will be available to reduce and treat fume emissions from other parts of the plant.
Appendix L
e erated continuously under negative pressure. d sampling stations for exclusively capturing capturing exclusively for stations sampling d ically advanced; they pose little technical risk to risk technical little pose they advanced; ically ion ports owing to external air ingress. Coarse Coarse ingress. air external to owing ports ion oat Ramp and Ellen St sampling stations capture capture stations sampling St Ellen and Ramp oat nt monitoring stations be reviewed with a view view a with reviewed be stations monitoring nt furnace, blast furnace and slag fuming plant) is first taken through a waste heat boiler (WHB) (WHB) boiler heat waste a through taken first is discharge. gitive egative pressure (off-gas is suction drafted drafted is suction (off-gas pressure egative chamber and exits via a sealed rotary valve into valve into rotary a sealed via exits chamber and one and an electrostatic precipitator (ESP) to to (ESP) precipitator electrostatic an and one ecord of acceptable emissions performance with with performance emissions acceptable of ecord d determinationd of slag fuming emissionson ocess heating in hydrometallurgical circuits. The The circuits. hydrometallurgical in heating ocess s produced by thereaction vessel. Comprised of ramatically reduced emissions from this section of section this from emissions reduced ramatically accessed through ports to allow inspection and and inspection allow to ports through accessed ith a site on the ‘island’. ‘island’. the on site a ith rade of the slag fuming baghouse stack fan and and fan stack baghouse fuming slag the of rade tion of the gas cleaning and acid plant as these ar these as plant acid and cleaning gas the of tion re re being cooledvia quencha tower and ducted to prior to atmospheric discharge. Systems for gas gas for Systems discharge. atmospheric to prior een removed well upstream of the catalytic catalytic the of upstream well removed een wo distinct gas streams – process off-gases and and off-gases – process streams gas wo distinct 5 July 2013 5 July EMISSIONS CONTROL SLAG FUMING PROCESS AND EMISSION IMPROVEMENTS PROCESS OFF-GAS
3.3.5 3.4.1 respect to metals. metals. to respect industry standard systemswith a long established r
can be readily and separately identified, such as w cleaned, and captured fully are – that air hygiene capture and handling are establishedlong and techn off-gase rich sulphur is the stream gas The primary approximately12-14% sulphur dioxide,this hot gas occasionally is that system enclosed fully a is WHB cleaning whilston line.Because the WHB is under n inspect the escape cannot fume boiler), the through boiler the of bottom the to falls WHB the from dust fu preventing conveyer, hot other or screw sealed a 3.4 t are there smelting, bath enclosed of cases all In slag fuming emissionsplant will enable a considere d has this that view the supports data plant Whilst (EBS performance plant process specific ensuring to pr or cogeneration electricity for steam to produce cycl a through is passed off-gas WHB, the Following determine vector using studies apportionment Source B the present At levels. lead air community ambient motor was conducted,enabling the baghouseto beop of ambie locations the recommended is it plant, the befo dust, particulate of fractions last the remove a variety of potential sources. In 2011 a major upg major a 2011 In sources. of potential variety a the upgrade project. is plant acid sulphuric the from gas tail The plant. acid sulphuric and circuit removal mercury a b having these Pb ofparticulates, free essentially opera the discuss to proposed not is It converters.
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3.4.2 HYGIENE VENTILATION
The second and larger gas stream is broadly referred to as hygiene ventilation and covers point source draughting to control dust and fume emissions. The mode of action is high volume air suction through an appropriately sized baghouse. The baghouse contains purpose designed microfiltration bags designed to remove sub-micron particle matter from the gas stream, before ventilating the cleaned air to atmosphere. Continuous, real-time gas and particle analysers are used to constantly verify compliance with relevant licence conditions. Such an example is the all stack emission monitoring system at Port Pirie which monitors sulphur dioxide and TSP (total suspended particulates), enabling changes to be detected and responded to. Use of baghouse style air filtration is a well established and technically advanced discipline in common use throughout the industrialised world. Recent advances include the use of Gore-Tex and ceramic filters to enable high temperature filtration and reduce the infrastructure requirements (and hence capital and maintenance costs) upstream of the baghouse.
High volume draughting hoods are designed and fitted at all process interfaces where fume or process gas can escape. Primary point sources are the furnace off-gas interface where this cannot be hard-ducted, together with all raw materials feed ports and slag/bullion offtakes. Secondary sources are molten material handling systems (crucibles, transfer launders, casting systems) and dry raw material transfer points. In general, all conveyers used to transport dry materials are enclosed within a conveyer gallery, such that external weather events have no bearing on material containment.
High volume draughting points create a substantial, but localised negative pressure environment such that abnormal emission events can be fully captured. Perhaps the best illustration of this was the observation by the EHWP of the feeding and lance port of the ISASMELT furnace at Umicore Hoboken. The violent nature of the furnace reactions occasionally leads to ejections of fume and small particles from the top of the furnace. The large volume suction hood fitted around this port enabled visibly rapid and complete fume capture; there was no evidence of fume or dust escaping the system.
Appendix L cs, and rie has a dry and hot climate. This has an an has This climate. hot and dry a has rie the delegation in Europe and Canada. lematic, in particular if any quantitative quantitative any if particular in lematic, s including batteries, fuel cells, automotive automotive cells, fuel batteries, including s isonof air quality and blood lead data for ers at both smelters were willing to provide the the to provide willing were smelters both at ers Hoboken since 1887. It is a polymetallic metals metals polymetallic a is It 1887. since Hoboken e e wouldobtain visas and useful environmental mmarises the data and key observations. These These observations. key and data the mmarises smelters operating in the West – Umicore at at Umicore – West the in operating smelters d by face to face discussions. Furthermore, by Furthermore, discussions. face to by face d publicly available however useful interrogation interrogation useful however available publicly anada. anada. n trends that can be observed for each smelter smelter each for observed be can that trends n enium, tellurium, bismuth, antimony,tin and ad, ad, nickel,copper, silver, gold, platinum, al verbal advice that they would not normally put put normally not would they that advice verbal al smelters operating SKS technology in China. China. in technology SKS operating smelters graded. The delegation included RobThomas, cly available. The smelter operators were also also were operators smelter available. The cly logy transformation, the EHWP formed formed a EHWP the transformation, logy imate - Hoboken has a cool and wet climate, Teck Teck climate, wet and cool a has Hoboken - imate performance of the Port Pirie smelter, post- smelter, Pirie Port the of performance less steel, glass industry, flat screens, electroni screens, flat industry, glass steel, less 5 July 2013 5 July UMICORE (HOBOKEN, BELGIUM) UMICORE (HOBOKEN, OBSERVATIONS OF BEST AVAILABLE TECHNOLOGY TECHNOLOGY BEST AVAILABLE OF OBSERVATIONS
4.1 in operating been have predecessors its and Umicore palladium, rhodium, iridium, ruthenium, indium, sel and understanding of the data could only be achieve le including metals of range a produces and smelter of use range a broad have Their products germanium. Hoboken in Belgium and Teck Resources at Trail in C in Trail at Resources Teck and Belgium in Hoboken is smelters both for data environmental the of Much holding detailed discussions, theenvironment manag publi not is that information other with delegation cl different a has smelter Each smelters. different prob comparison direct makes and data the on impact and useful qualitative judgements can bemade. su smelters two the from observations following The likely the on EHWP the for insight critical provide transformation. stain wires, cables, cells, photovoltaic catalysts, 4. In orderto understand likelythe effects of techno up been have that smelters lead visit to delegation Mark Hibberd and AndrewGilbert. Matt Howell joined Ideally the delegationwould have arranged tovisit w that unlikely was it that advised were we However visit lead to made arrangements therefore We data. practic some with delegation the to provide willing in writing. compar the is EHWP the for complications the of One has dry summers andsnow-bound winters, and Port Pi commo are there Nevertheless, analysis is required. various alloys. alloys. various
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They process around 350,000 tonnes of more than 200 different types of raw materials including both mine concentrates and recycled materials. Recycling is an important part of their business and they recover up to 17 different metals from recycled materials. They have a significant research group and its programs are largely focussed on transforming metals into hi-tech materials. Their business model fits strongly with environmental trends – resource scarcity, electrification of the automobile, more stringent emission control and renewable energy.
The company has a strong focus on closing the loop by securing supply and recycling materials and with the aim of also minimizing environmental impact of their operations.
Figure 6 shows the location of the Umicore smelter in Hoboken, a suburb of Antwerp, Belgium. In 1996 the company made a strategic decision to clean up the pollution from the plant and undertake an ‘extreme makeover’. As part of this investment, they commissioned a new enclosed bath smelting technology, ISASMELT, in 1997.
Figure 6. Location of the Umicore smelter in Hoboken, a suburb of Antwerp. The image shows that there is housing and monitoring sites located immediately adjacent to the smelter. Monitoring site locations from (VMM 2009).
Appendix L
, which is
after four years years after four (Figure 7). This led led This 7). (Figure 3 3 (AirBase . 2012) ite adjacent to Umicore smelter shown as as moving shown smelter to Umicore adjacent ite old children) in 1997 to a range of 7 - 10 µg/dL µg/dL 10 7 - of range a to 1997 in children) old h a range of 0.15 – 0.2 µg/m 0.2 – 0.15 of range a h ant measure of overall population performance, performance, overall population of measure ant ofblood lead levels thein surrounding 10 µg/dL) to also be used to assess performance. performance. assess to used be also 10 µg/dL) to sioned in 1997. Data from from Data 1997. in sioned as also increased substantially from 60% (in 2003) 2003) 60% (in from substantially also increased as 5 are forare the suburbof Moretusburg (in Hoboken), y skewed. This requires another measure, the the measure, another requires This yskewed. quality improved dramaticallywith a reduction from e median of data that has a log-normal distribution has of a log-normal median that e data before the transformation to about 0.6 µg/m 0.6 about to transformation the before 3 5 July 2013 5 July . Air lead concentrations at community monitoring s monitoring at community concentrations lead Air . The geometric mean (or geomean) is a measure of th a measure (or geomean) is mean geometric The typically the case for blood lead levels. to a concomitant reduction in the geometric mean geometric the in reduction concomitant to a community from an average of 20 µg/dL (for 2-6 year 2-6 (for µg/dL 20 of average an from community data These 8). (Figure 2012 to 2007 period the for where all houses are between 10 and 650 m from the smelter the boundarym from 650 (Figure 6). and 10 between are houses all where import an is level lead of blood mean geometric The however the blood lead distribution issignificantl
percentage of children belowthe health guideline ( h percentage this that seen be can it 9 Figure From available. not data was 2011; earlier in 90-95% to
5 annual averages. The ISASMELT technology was commis was ISASMELT technology The annual averages. Figure 7 lead air plant, of this introduction the Following an annual average of about 1 µg/m 1 about of average annual an
and then with further improvements to a plateau wit plateau a to improvements further with then and
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Figure 8. Reduction in geometric mean blood lead levels for age groups of children in Hoboken since the introduction of the new technology at the Umicore smelter. From (Nelen and Thys 2011).
Figure 9. Increase in percentage of all children in Hoboken with blood lead levels below 10 µg/dL since the second half of 2003. Data from (Nelen 2005-2012).
It is important to note that blood lead reduction occurs at a slower pace than air lead reduction. This is because air lead reduction is an immediate process. Blood lead reduction, on the other hand,
Appendix L
notified industrial sources from January January from sources industrial notified limit was also applied to these sources. sources. these to applied also was limit 3 05), is 10 µg/dL. µg/dL. 10 is 05), ing at Port Pirie is about 200 metres from the the from metres 200 about is Pirie Port at ing in January 2005. A transitionary value of value transitionary A 2005. January in of Trail, British Columbia (Figure 10). Like Like 10). (Figure Columbia British of Trail, 3 tations in Hoboken are located within the the within located are Hoboken in tations oad range of uses including galvanizing, 11). ree different directions (see particularly the the particularly (see directions different ree g/m ch closer than licence monitoring sites in Port Port in sites monitoring licence than closer ch ne into blood before excretion in urine, all of of all urine, in excretion before blood into ne the right-hand part of Figure 15). Because of the the of Because 15). of Figure part right-hand the Port Pirie, there is housing close to the smelter, smelter, the to close housing is there Pirie, Port metal and chemical products but with an an with but products chemical and metal close to the smelter, in fact it can be seen from from seen be can it fact in smelter, the to close ipal wind directions along the valley), there is an is there valley), the along directions wind ipal d paper production, fertilisers and bleaching rds.htm was set at 0.5 µg/m 0.5 at set was 6 5 July 2013 5 July was applied in the immediate vicinity of specific, vicinity immediate the in applied was 3 TECK RESOURCES (TRAIL,TECK RESOURCES CANADA)
http://ec.europa.eu/environment/air/quality/standa 2005 until January 2010, after which time the 0.5 µ 0.5 the time which after 2010, January until 2005 The blood lead recommendation, following (US CDC 20 CDC (US following recommendation, lead blood The
6 agents. housing is there Pirie, Port and Umicore to Similar th in nearby housing has smelter the that 10 Figure 4.2 town the in 1890s the since operating been has Teck Umicore, it is a polymetallic smelter producing 18 producing smelter polymetallic a is it Umicore, emphasison zinc and lead.Their products have br a an pulp cables, optic fibre screens, LCD batteries, in areas Tadanac and Trail East Trail, West shaded bo like tissues from losses or transfers on depends limited. time are which to similarly that is observation important Another hous nearest (The boundary. the from metres 10 only Primary). West Pirie and St Pirie (Oliver The air lead standard in Europe (princ river the along areas population significant boundaryof the smelter). The mainair monitoring s mu is which 6), Figure (see estate housing adjacent extensive monitoring network thein region (Figure 1.0 µg/m 1.0
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Figure 10. Location of the Teck Resources smelter on the Columbia river in Trail, Canada showing the location of some of the housing in relation to the smelter.
Figure 11. Locations of the four main air quality stations (Birchbank, Butler Park, Warfield and Columbia Gardens) and some of the dustfall monitoring sites () around the Teck Resources smelter in Trail. The main air quality monitoring site at Butler Park is about 2 km from the smelter boundary.
Appendix L
and air and air whichplateaued over the 3 ns in Trail in August (month with highest values values highest (month with August in Trail in ns xperienced a dramatic reduction in air lead lead air in reduction dramatic a xperienced aged 6 months to 3 years) in 1997 to an an to 1997 in years) 3 to months 6 aged because of the snow cover in winter at Trail Trail at winter in cover snow of the because r this are that the monitored population all lives lives all population monitored the that are this r away with the snow melt thus providing better better providing thus melt snow the with away omitant reduction in blood inlead the surrounding been a little better than Umicore – average of of – average Umicore than better little a been by about 50% (British Columbia Ministry of Ministry Columbia (British 50% about by reduction of total air lead emissions by about 80%, about by emissions air total lead of reduction les and different locations of zero for blood lead blood lead zero for of locations and different les annual average (1997) to around 0.5 µg/m 0.5 around to (1997) average annual 3 5 July 2013 5 July Time series of air lead and blood lead concentratio lead lead and air blood of series Time (THEP 2011) lead. period 1998 to 2011 (Figure 12). This led to a conc a to led This 12). (Figure 2011 to 1998 period children (for µg/dL 12 of average an from community 12). (Figure 2011 to 2001 from µg/dL 5 of average 5 µg/dL compared with 7 to 10 µg/dL. The reasons fo reasons The µg/dL. 10 7 to with compared 5 µg/dL concentrations from 1.6 µg/m 1.6 from concentrations reduction. lead air than pace a slower at occurred reduction lead blood Umicore, with As has Teck at reduction lead blood the Interestingly and Teck at than smelter Umicore the to closer much community. the for protection Figure 12. Environnment 2009). Following commissioning, theye sca 2011. different – Note 1991 from blood lead) of which holdsthe fine particles and thenwashes them and a reduction in fine,mobile dust lead loadings they efficiency, processing metal improve d an pollution lead the up clean to order in 1997, In in resulted which smelter, lead Kivcet a installed
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Although the British Columbia objective for annual average lead in TSP is 1.0 µg/m3, the current air quality ‘target’ for Teck is the THEC (Trail Health and Environment Committee) goal of 0.2 µg/m3 at their community monitoring sites at Butler Park and Birchbank. Their blood lead health guideline is 10 µg/dL.
Figure 13 shows a longer history back to 1975 of the geometric mean of blood lead levels in Trail and a comparison with the US average, which was 15 µg/dL in 1975. Figure 14 shows the corresponding percentage of 6-36 month aged children with blood lead levels below 10 µg/dL. This has increased from 30-40% before the technology upgrade to values above 90% post KIVCET.
Figure 13. History of geometric mean of blood lead levels in children in Trail since 1975 compared to US averages. (THEP 2011)
Appendix L
2011. 2011.
(THEP 2011)
with blood lead levels below 10 µg/dL since since µg/dL 10 below levels blood lead with l children over two decades spanning two the over l children ren above or below 10 µg/dL are metrics metrics are µg/dL 10 or below above ren el. The figure shows the dramatic shift to the left the to shift dramatic the shows figure The el. at Trail, but also the continued presence of a a of presence continued the also but Trail, at
velsin the population (Figure 15),which showsthe c mean of 13 µg/dL in 1991 decreased to 5 µg/dL in in decreased µg/dL 5 to 1991 in µg/dL c 13 mean of -hand part of the figure. figure. the part of -hand
5 July 2013 5 July Change in distribution of blood lead levels in Trai in levels blood lead of distribution Change in History of percentage of 6-36 month aged children aged month 6-36 of percentage History of (THEP 2011)
Figure 15. geometri The technology. KIVCET the of installation right the in shown are & 3 2 of Areas locations The 1991. 1991. child of percentage the and mean geometric the Both Figure 14. le lead blood of distribution full the from derived
proportionof the population ateach blood lead lev of the distributions since the 1997 transformation transformation 1997 the since distributions of the levels. lead blood higher with children of fraction
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4.3 CONCLUSION RE LIKLEY POST-TRANSFORMATION PERFORMANCE AT PORT PIRIE
Despite the differences between the Umicore and Teck smelters, both sites recorded major reductions in air lead and blood lead levels following the introduction of new smelter technology. To assist with estimating the likely changes that would occur at Port Pirie following the proposed Transformation, the data on air lead and blood lead reductions at Hoboken and Trail have been combined in Figure 16 and Figure 17. The data show significant scatter because of year-to-year variations in climate and production levels as well as the impact of ongoing improvements. Indicative trend lines (drawn by eye) show that halving of air lead levels occurred after 1–4 years, whereas halving of blood lead levels took about 7-9 years. However, blood lead levels in Port Pirie (Figure 29) are already significantly lower than pre-transformation levels at Trail and Hoboken; the results in Section 7 provide a better understanding of the relationship between reductions in air lead and blood lead. Legacy lead (Section 6.3.3) can also make a significant contribution to blood lead levels.
Figure 16. Comparison of the rate of reduction of air lead concentrations following technology transformations at Umicore and Teck (data replotted from Figure 7 and Figure 12).
Appendix L
evels following technology transformations at technology transformations following evels Figure 12). 5 July 2013 5 July Comparison of the rate of reduction of blood lead l of reduction of the of rate Comparison
Figure 17. and 8 Figure from replotted (data and Teck Umicore
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5. AIR QUALITY DATA FOR PORT PIRIE
5.1 SPATIAL VARIATION IN AIR LEAD CONCENTRATIONS
Nyrstar currently operates a dozen monitoring sites across Port Pirie with high-volume samplers collecting 24-hour TSP (total suspended particle) samples, which are analysed for a range of metals including lead. Figure 18 shows the distribution of annual average concentrations across the city from the last five years (2008-2012) with fitted smoothed contours shown in yellow.
Figure 18. Five-year (2008–2012) average air lead concentrations (units of µg/m3) at the Port Pirie monitoring sites with fitted smoothed contours shown in yellow.
The shape of the contours is strongly influenced by the dominant wind directions (see Figure 1) with the highest concentrations at a given distance to the southeast of the smelter and lower
Appendix L at
7 e dominant source of air lead in Port Port in lead of air source e dominant average rainfall and 60% more rain days than than moredays rain 60% and rainfall average not from the smelter sector) were less than than less were sector) smelter the from not trations at the licence monitoring sites monitoring licence the at trations crease of 11% p.a. in annual average average annual in 11% p.a. of crease likely due to higher than average rainfall – the the – rainfall average than higher to due likely -year average concentrations were used to to used were concentrations average -year nsistently lower than at any time in the previous previous the in time any at than lower nsistently the result of a wide range of tenby10 projects to to projects tenby10 of range wide a of result the ith each value plotted at the end of the averaging averaging of the end the at plotted value each ith l to the ratio of the annual averages in Figure 18 Figure in averages annual of the ratio the to l at Pirie West Primary School. The 30-year record record 30-year The School. Primary West Pirie at have been filled using surrogate data fromother rogate data. Note that the vertical axis is a log scale log a is axis vertical the that Note data. rogate study of the Nyrstar smelter (PAE Holmes 2012) 2012) Holmes (PAE smelter Nyrstar the of study y School and Olivery Street. and School . This confirms that current smelter sources are th are sources smelter current that confirms This . 3 5 July 2013 5 July HISTORICAL AIR LEAD TRENDS
The licence monitoring sites are Pirie West Primar (determined from days when thewind directionswere µg/m 0.005
7 5.2 is network Nyrstar the of site running longest The record the in gaps few A axis). time the on period five The southwest. and south the to concentrations of running annual averages is given in Figure 19 (w equa applied factor scaling a with sites monitoring minimise scatter due to year-to-year variations. variations. year-to-year to due minimise scatter emissions fugitive the in latest reported Analysis showed that 2010/2011in background air lead concen sur the with site the at that to Primary West Pirie fit exponential an decade, recent most the on g Focussin clearly. more changes proportional to show de average an been has there that shows data the to concentrations with lead levels since 2008 being co being 2008 since levels lead with concentrations most are 2011 in concentrations lower The years. 25 above 30% had 2011 June to 2010 July from months 12 average. The reductions over the last ten years are years ten over the last The reductions average. smelter. the of impact environmental the reduce Pirie.
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Figure 19. Running annual average lead concentrations at Pirie West Primary School over the last 30 years. Some gaps in the record at this monitoring site have been filled using data from other monitoring sites in Port Pirie. See text for details.
The monitoring sites used for assessing EPA compliance are the Pirie West Primary School and Oliver Street sites. Figure 20 shows the 14-year record of annual average air lead concentrations from the Oliver Street monitoring site, again with some surrogate data adjusted as described for Figure 19. As at Pirie West Primary School, an exponential fit shows that there has been an average decrease of 11 % p.a. over the last decade and with a similar rainfall-induced dip in 2011. Indeed analysis of data from each of the monitoring sites show average reductions of 8–12 % p.a. over the last decade, with the decrease at the Terrace averaging 17% p.a., probably because of its closer proximity to the pit, which was the target of significant improvements as part of the tenby10 projects.
Appendix L
s in Port Port in s
. r Street monitoring site over the last 14 years. years. last 14 the site over monitoring Street r r lead and deposited lead dust. Figure 21 shows shows 21 Figure dust. lead deposited and lead r hich contribute to the lead reservoirs discussed discussed reservoirs lead the to contribute hich y is via ingestion rather than by inhalation, it is it inhalation, by than rather ingestion via is y lead deposition rates across the Port Pirie Pirie Port the across rates deposition lead are considered in more detail in Section 6.3.3. 6.3.3. Section in detail more in considered are entration is a useful measure of the amount of lead amount the of measure useful a is entration e been filled using data from other monitoring site monitoring other data from using filled been e annual averages at these sites in Figure 18 Figure in sites at these annual averages 5 July 2013 5 July Running annual average lead concentrations at Olive lead concentrations annualRunning average LEAD DEPOSITION RATES
As the primary route for entry of lead into the bod the into of lead entry for route primary the As 5.3 dust of lead sources various The 6.3.4. Section in Figure 20. Some gaps in the record at this monitoring site hav site monitoring at this record gaps the in Some the of scaled by ratios been the have which Pirie, w smelter, the from emissions to due deposited dust
the strong linear correlation between air lead and and lead air between correlation linear strong the conc lead air that indicates This sites. monitoring important to understand the relationship between ai
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Figure 21. Relationship between average lead deposition and average air lead concentrations at the Nyrstar monitoring sites across Port Pirie.
The ratio of lead deposition rate to air lead concentrations in Figure 21 is 1.0 ± 0.3 (mg/m2/day) per (µg/m3). This compares with a slightly higher ratio of 1.8 for the Butler Park site in Trail8, although data are only available for the month of August, and a much larger ratio of about 8 at Hoboken9. The reasons for the differences have not been investigated but it is postulated that there is a higher proportion of coarse dust (with deposits more quickly) at Hoboken than at Trail or Port Pirie.
8 Butler Park is in Area 3 (Figure 15), so the average August dustfall in Areas 2/3 from 2008-2010 of 0.85 mg/m2/day can be compared with the average August TSP air lead concentration at Butler Park for these years of 0.48 ug/m3 (THEP 2011).
9 The lead deposition rate at site HB01 (Figure 6) was 1.3 mg/m2/day in 2009 and the annual average air lead concentration in PM10 was 0.17 µg/m3 (VMM 2009). Note that this air lead concentration is in PM10, whereas the results for Trail and Port Pirie are in TSP. Comparisons of Port Pirie data from Oliver St and Ellen St monitors show that TSP air lead concentrations are on average 2.3 times larger than PM10 air lead concentrations, but this TSP/PM10 ratio depends on the relative proportions of the various dust sources and is expected to vary from smelter to smelter.
Appendix L
he e is larly e in this report, the aim is for continual continual for is aim the report, this e in er decilitre (μg/dL) and that children’s lead lead children’s that and (μg/dL) decilitre er closed in 2003-4. 2003-4. in closed Australian Premier’s seven strategic priorities — — priorities strategic seven Premier’s Australian alth collects about Port Pirie children’s blood blood children’s Pirie Port about collects alth n hadn blood lead levels above 10μg/dL (Figure ith blood ith lead levelsabove 10μg/dL after f thef 130 children aged0-4 years had blood lead fficult as child-activity patterns may be different be may patterns child-activity as fficult ave been discussed in Section 4; the smelter at at smelter the 4; Section in discussed been ave years after the 1997 smelter technology technology smelter 1997 the after years ent NHMRC recommendation: that all Australians Australians all that recommendation: NHMRC ent d 0-4 years because this is the population that is is that population the is this because years 0-4 d bsequently is the data that has been collected for for collected been has that data the is bsequently er the age of 3 years had blood lead levels above above levels lead years blood 3 ofhad age the er losed or significantly reduced its lead emissions, lead emissions, its reduced or significantly losed blood lead levels were reported from Cockle Creek Creek Cockle from reported were levels lead blood the child’s exposure – the dry climate in Port Piri Port in climate dry the – exposure child’s the areas havesubsequently reduced. Three cities have e, lead exposure pathways, andcontributors to lead rity is intended to concentrate efforts and drive t drive and efforts concentrate to intended is rity ill provide better health outcomes for Port Pirie Pirie Port for outcomes health better provide ill in Port Pirie is to ensure that residents, particu residents, that ensure to is Pirie Port in technology transformation 5 July 2013 5 July HISTORICAL HISTORICAL PERSPECTIVE INTRODUCTION INTRODUCTION LEAD EXPOSURE IN PORT PIRIE PIRIE IN PORT EXPOSURE LEAD
children, have blood lead levels that meet the curr the meet that levels lead blood have children, should have blood lead levels below10 micrograms p exposure shouldminimised. be As discussed elsewher South of the one with aligns aim This improvement. prio strategic This child’. every for chance ‘every
9), and at Trail, 9% of the 106 children tested und tested children 106 of the 9% Trail, at 9), and most sensitive to the health effects of lead and su and of lead effects health the to sensitive most 6.2 c either has smelter lead active an where cities In children’s blood lead levels in nearby residential He SA that data to comparable is that data recorded h Trail and Hoboken at reductions – the levels lead Australia Wales, South New Boolaroo, Cockle Creek, w remained children young some cities, three all In 14 2011, In closure. smelter or reduction emission transformation in Hoboken, about10% of allchildre that time last the 2005-6, In 14). (Figure μg/dL 10 o 7% closed, smelter lead the after years three and di is Comparison 22). (Figure μg/dL 10 above levels exposure. The discussion is limited to children age children to limited is discussion The exposure. time. of period extended an of smelter aim The to contributes soil bare which to extent the is as This section discusses sources of lead in Port Piri Port in of lead sources discusses This section 6. 6.1 children. hildren, particularly in the first five years of of years five first the in particularly children, for outcomes health improve to government of work w levels lead blood reducing that clear is It life. conducive to bare soil. soil. bare to conducive
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Figure 22. Changes in percentage of children with blood lead levels above 10 µg/dL in Cockle Creek following smelter closure in 2003.
6.3 LEAD EXPOSURE FOR CHILDREN
6.3.1 BLOOD LEAD RECOMMENDATIONS
The National Health and Medical Research Council (NHMRC, 2009a) states:
‘Based on the research evidence on the effects of low-level exposure to lead, it is not possible to make a definitive statement on what constitutes a ‘safe level’ or ‘level of concern’ for blood lead concentrations.’
Therefore the Council published a recommendation in 2009:
• All Australians should have a blood lead level below 10 µg/dL. • All children’s exposure to lead should be minimised. • All women are advised to minimise their exposure to lead both before and during pregnancy and also while breastfeeding.
The World Health Organisation (WHO) also maintains a guideline of 10 μg/dL.
In 1999-2000 the geometric mean blood lead level in the US was 2.4 µg/dL for 12-14 month old children. In 2012, the US CDC (CDC, 2012) replaced its ‘level of concern’ with a childhood blood lead reference value based on the 97.5th percentile of population blood lead levels in children aged 1-5
Appendix L t n
d reproductive age), and 15 µg/dL (womenwho ncentrations in the child’s environs (i.e. at the the at (i.e. environs child’s the in ncentrations nt Australian standard (NOHSC 1994) is that is 1994) (NOHSC standard Australian nt vides the values of 3.5 μg/dL for children aged 3- aged children for μg/dL 3.5 of values the vides s, Figure 25 shows the strong impact of reducing reducing of impact strong the shows 25 Figure s, re 23 and in more detail in Figure 27, as well as as well as 27, Figure in detail more in 23 and re children with blood lead levels below10 µg/dL. than those for the general population. These These population. general the for those than ren aged 1-5 years who have blood lead levels levels lead blood have who years 1-5 ren aged between smelter leademissions and children’s factors contributing the and (blue) sources minated dust and soil) thein child’s living y have a blood lead level of 50 µg/dL (all men and and men (all µg/dL 50 of level lead blood a y have on and particularly not for children, but the the but children, for not particularly and on to other factors. These include individual individual include These factors. other to nce that lead has effects at very low levels. It is It levels. low very at effects has lead that nce eflecting the complexity of the relationship. For a For relationship. the of complexity the eflecting ng a child’s blood lead level, not just the air lea air the just not level, lead blood child’s a ng versus the annual average air lead concentration a concentration lead air average annual the versus n explain less than 30% of the variation in their their in variation of the 30% than less explain n 5 July 2013 5 July FACTORS INFLUENCING CHILDREN’S BLOOD LEAD LEVELS
6.3.2 their residence shows a wide scatter (Figure 24), r 24), (Figure scatter wide a shows residence their
Figure 23 shows the complexity of the relationship relationship the of complexity the shows 23 Figure estimated that there are currently 450,000 US child US 450,000 currently are there that estimated blood levelslead withmultiple variables —the lead influenci many factors are there That is, (orange). concentration. A plotofeach individual child’s blood lead levels air lead concentratio in variations the individual, blood lead levels, leaving 70%of the variation due years. This is recent most currently the on 5 μg/dL, based andwillyears 4 be updat every ed population surveys. Its rationale is basedon evide μg/dL. 5 above pro percentile 95th of value reference a Germany In Figu in shown pathways, exposure lead in variations environment and uncertainty surrounding air lead co child receptor). However, on a population-wide basi of number the increasing on concentrations lead air 14 years, 7 μg/dL for women and 9 μg/dL for men. men. for μg/dL 9 and women for μg/dL 7 years, 14 Occupational health standards are generally higher or breastfeeding). are pregnant conta (lead contamination lead legacy in variations standards are not relevant for the general populati general for the arerelevant not standards numbers are listed here for completeness.The curre if the jobs lead-risk from be removed workers shall of (women µg/dL 20 age), of reproductive not women
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Figure 23. Schematic diagram of lead exposure for children showing lead sources (blue) and contributing factors (orange) that influence the child’s exposure level.
Appendix L hildren hildren PA e the with
(Cantrell 2008). in Port Pirie with blood lead levels below 10µg/dL below levels blood lead with Pirie Port in he 12-month average air lead concentrations concentrations lead air average 12-month he fficulty in reducing exposure and green the least, least, and the green exposure reducing in fficulty at Pirie West Primary monitoring site, one of the E the site, of one monitoring Primary West at Pirie these. The two lines denote regression models c for models regression denote lines these. two The tainty in both variables bothtainty in variables iscussion in text. text. in iscussion 5 July 2013 5 July Regression of percentage of 1–4 year old children children old year 1–4 of percentage of Regression Scatter plot of individual blood lead levels and t levels blood lead individual of plot Scatter in high risk (red) and low risk (blue) areas. See d See areas. (blue) risk and low (red) risk high in yellow and blue have a level of difficulty between between of difficulty a level have and blue yellow licence sites. The bivariate fit accounts for uncer for fit accounts bivariate The sites. licence against the annual average air lead concentrations concentrations air lead annual average the against exposure index, where red indicates the greatest di greatest the red indicates index, where exposure d’s place of residence (in 2005). The colours denot colours 2005). The (in residence place of d’s chil to the closest site by monitoring the measured
Figure 25.
Figure 24.
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6.3.3 LEAD SOURCES
The source of lead that Port Pirie children are ultimately exposed to is principally smelter derived with rare contributions from other sources, occasionally lead paint. Smelter lead emissions can directly deposit into home reservoirs (contemporary contamination) or feed into home reservoirs via a number of steps (legacy, also called historic, contamination of dust and soil in Port Pirie environs by smelter emissions and motor vehicle emissions over previous years).
Contemporary lead exposure arises principally from fugitive emissions from the smelter site rather than stack emissions, the latter of which are estimated to make up about 10% of smelter lead emissions and a smaller proportion of air lead concentrations measured in Port Pirie due to the better dispersion from elevated sources. These fugitive emissions originate from smelting processes and on-site lead deposits (e.g. stock piles of raw materials and deposits on roads, roofs, tarmacs, bare soil, etc.). The time that elapses between emission of a lead particle from the smelter and ingestion of the particle by a child is unknown. Both contemporary lead exposure and legacy lead exposure are smelter sourced, but separated temporarily by some unknown period of time.
Lead dust particles travel downwind at a distance dependent upon particle size and wind strength and other complex meteorological parameters. Particles may land on other surfaces and be re- entrained into the air. This latter process is energy intensive requiring high wind gusts such as those observed on hot windy days prior to a synoptic front. Houses are readily penetrated by airborne lead particles and are very effective in retaining them—the age of housing stock is a key feature that determines dust particle entry.
Lead dust particles can also be mechanically transported, where lead particles lodge onto objects such as clothes (an important direct source from the smelter if workers wear their on-site clothes home), shoes, animal fur, wheels of children’s prams and strollers, etc. These contaminated objects may then be directly handled and mouthed by the child, e.g. pets or wheels of stroller. Alternatively, as these objects pass across the floors of homes, lead can be transferred onto other surfaces, particularly adding to the carpet lead reservoir.
6.3.4 LEAD RESERVOIRS
Lead that is emitted from the smelter, or entrained by wind, or mechanically transported, adds to lead reservoirs that feed, to varying extents, into exposure pathways of the child. Lead reservoirs in a child’s living environment consist of lead-contaminated dust or soil inside or outside the child’s house or a building or facility where the child spends significant time such as child or day-care centre, kindergarten, grandparent’s house or playgrounds. Lead reaches home reservoirs in the vicinity of the child over days, months or years.
Appendix L he rpet moves lead particles in the vertical vertical the in particles lead moves rpet rd with exposed soil is the primary lead lead primary the is soil exposed with rd the leakiest. Homes in close proximity to the the to proximity close in Homes leakiest. the and and dust ingress also needsto be considered ets and yard soil is an option but re- but option an is soil yard and ets pet dust is located in the lower quarter of the of the quarter lower the in located is dust pet days. In general, thecondition of houses in s of air-borne lead and are, in general, older general, in are, and lead of air-borne s of the exposure risk posed by contaminated contaminated by posed risk exposure the of g the home. Wet-dusting and HEPA-filtered HEPA-filtered and Wet-dusting home. the g are constantly being re-supplied, evenvigilant d objects that leave the house, either remain remain either house, the leave that objects d the myriad of surfaces that comprise children’s children’s comprise that of surfaces myriad the emitted from the smelter deposits to the ground ground the to deposits smelter the from emitted in the lead reservoirs are the child’s residential residential child’s the are the lead reservoirs in ng that children are placed on impermeable impermeable on placed are children that ng ead contamination is lower in more southerly southerly more in lower is contamination ead ffectivenessof theseoptions under current bly matches the age of the homes – with poorer poorer with – homes the of age the matches bly This is the most accessible lead in the home for for home the in lead accessible most the is This ,even forthe most fastidious cleaner and esidential premises and is readily and constantly exposure. exposure. to a home is determined, in part, by the leakiness leakiness the by part, in determined, is home a to wling are at most risk of lead exposure. exposure. of lead risk most are at wling ucing with downwind distance from the smelter smelter the from distance downwind with ucing ng spaces are the primary lead reservoirs of the the of reservoirs lead primary the are spaces ng which compounds the issue of residential elling in a southerly direction from the smelter. T smelter. the from direction southerly a in elling controls to some extent the lead reservoirs in the the in reservoirs lead the extent some to controls INFLUENCE OF HOUSE LOCATION AND ITS DUST-PROOFNESS
5 July 2013 5 July 6.3.4.1
location and the dust-proofness of the house. Lead Lead house. the of dust-proofness the and location red smelter, the from distance to relative rates at concentration highest the with impinged are smelter clean surfaces, their hands are washed and dried an dried and are washed hands their clean surfaces, emission conditions. lead of amount the influencing factors primary The l environmental that such 21) Figure and 18 (Figure location residential Therefore, city. the of parts are homes weather-board – old envelope house of the wind-speed between relationship The homes. leakier exposure pathways(depicted in Figure 27). Because ensuri towards directed is attention much surfaces, re-enterin washed before thoroughly are or outside, vacuum cleaning isencouraged, but since reservoirs e the reduces carpets, of especially contamination, child’s environs and subsequently the child’s lead in particles of lead entry of ease the Furthermore, along with house related behaviours on hot or windy inevita Pirie Port in found gradient socio-economic families living in the highest lead impinged areas, Inside the home, carpet,soft furnishings and ceili home reservoir.Outside the home, an undeveloped ya car most that demonstrated has CSIRO The reservoir. difficult extremely removal makes This pile. carpet ca contaminated on Walking cleaner. vacuum powerful surface. the reaching particles some with direction cra are who children reason, this for and children, r within motion constant in is lead containing Dust on deposited and lead reservoirs from re-mobilised carp of Replacement them. eliminate cannot cleaning trav best, to poor of gradient a follows Pirie Port smelter. the to proximity
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To summarise, the high lead-exposure risk areas are Pirie West, Solomontown and the CBD (Figure 26). These suburbs are subject to greater lead-contaminated dust concentrations and greater lead load per unit surface area because they are in close proximity to the smelter and downwind from it and contain aged and poorer housing. Distance from the smelter and the south-west sector of Port Pirie in general provides the most protection, along with good quality homes (brick veneer has proven to be effective), and limited surrounding exposed soil, including yards, parks and footpaths.
Figure 26. Map showing the zones used by SA Health to specify risk of lead exposure.
6.3.5 LEAD EXPOSURE PATHWAYS
Children live within a complex web of lead exposure pathways. Each pathway has two distinct stages:
1. The passage of lead particles from the lead source, whether direct from smelter or indirectly via the environmental lead reservoir (e.g. lead-contaminated soil and dust) to the lead reservoirs in the vicinity of the child (home reservoirs). 2. The passage of lead particles from the lead reservoirs in the child’s environment into the child’s body.
Appendix L
, , , , etcetc screenscreen , , wheelswheels PramPram fabric fabric entranceentrance doordoor seatseat carcar baby baby handlehandle (Kranz B. 2004) school, child care, playgroup, playgroup, playgroup, care, care, child child school, school, , , friendsfriendsplayground playground homes, homes, trolleys,trolleys, shopping shopping dummydummy beddingbedding bottle teatteat bottle bottle babybaby toystoys clothing,clothing, of surfaces is a natural behaviour and is and behaviour natural is a of surfaces d’s environment tion of lead particles is to contaminate an an contaminate to is particles of lead tion ome particles will be absorbed. Ingestion is the the is Ingestion absorbed. be will particles ome sure. Simon et al (2007) estimated that that estimated (2007) al et Simon sure. he most efficient and effective exposure exposure effective and efficient most he derived from its mother. Since lead is chemically chemically is lead Since mother. its from derived lounge or hard surface to an object that is is that object an to surface or hard lounge is, the child’s age is a primary factor in the lead the in factor primary a is age child’s the is, d therefore the foetus is exposed, achieving the the achieving exposed, is foetus the therefore d e the respiratory route of exposure for a child child a for exposure of route respiratory e the toy, a dummy or food. When the object is is object the When or food. dummy a toy, SmelterSmelter siblingssiblings parentsparents outside leaded dust dust leaded leaded outside outside outside toys, pets pets toys, toys, outside outside sofasofa blinds blinds ,, , , shoesshoes udyudy carpet carpet floorfloor blanketblanket curtains curtains near babybaby near near suspended dustdust suspended suspended , , INFLUENCE OF CHILD’S AGE air flow, including including including flow, flow, air air activity activity and and fans fans by by ,,
sills sills skirtingsskirtings 5 July 2013 5 July Schematic of the lead exposure pathways in the chil the in pathways lead the exposure of Schematic mantles etc.etc. mantles mantles 6.3.5.1 NotNot directlydirectly associatedassociated withwith thethe homehome High Pb loading in in study in study HighHighthis this PbPbloading loading HighHigh expected,expected,Pb Pb notnot testedtested inin thisthis studystudy LowLow to to moderate moderate Pb Pb in in this this study study •• •• •• •• Low Low toto moderatemoderate PbPb expected,expected, notnot testedtested in in thisthis stst
As explained above, the most important as well as t as well as important most the above, explained As highly age-related, beginning at 5weeks old. That Figure 27. primary route for entry of lead into the body; whil body; the into of lead entry for route primary expo total to contribution small extremely an makes carpet, as such reservoir, lead the from is pathway mouthed—most commonly the hand or fingers. Mouthing an mother the by absorbed is it calcium, to similar object that the child will mouth such as a hand, a a hand, a as such mouth will child the that object s swallowed, if and mouth, the enters lead mouthed, inhalation to contributes contribution less its than estimated 2% whereas 2007) the (USEPA US EPA 1%. be exposure pathway. is newborn of the load lead the mouthing, to Prior destina penultimate the but complex are stages Both
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same blood lead level as the mother. Furthermore, pregnancy mobilises the mother’s calcium stores to ensure that the growing foetus is not deprived of calcium, which also releases lead into the blood because lead is stored in the same bone-stores as calcium. The mother’s body burden of lead together with her blood lead level determines the blood lead level and body burden starting point of a newborn.
On birth, the child’s exposure is limited to incidental lead contamination, such as re-entrained lead and lead on clothing or bed linen. However, once motor control begins to develop, the natural exploratory behaviours of the child increases its range and the potential for lead exposure increases rapidly from this period onward. The most critical stage is when the child begins to crawl because it is almost certain that the child will not be protected from contaminated surfaces without severely curtailing natural behaviours (e.g. placing the child into a ‘playpen’). It has been found that as a child transitions from crawling to standing he or she will have reduced hand-lead contamination at each behavioural milestone. A toddler is likely to have a lower exposure indoors than when he or she was crawling. However, if the toddler is allowed to explore the contaminated outdoor environment he or she can quickly become highly exposed. In exceptional circumstances some children exhibit a pattern of behaviour called ‘pica’, that is eating of non-food objects. These children are at particular risk of excessive exposure to lead. The decrease in blood lead levels with age is also seen in the data from Umicore in Figure 8.
6.3.5.2 INFLUENCE OF SOCIO-ECONOMIC STATUS (SES)
In addition to the impact of social economic status (SES) on housing condition and the lead reservoir (section 6.3.4), SES also impacts on other aspects of lead exposure within the caring environment of the child. For example, lower SES is associated with poorer nutrition, reduced focus on hand and house hygiene, less resources available for cleaning and barriers against lead reservoirs e.g. mattresses, high chairs and educational disadvantage (especially care-givers) reduces the effectiveness of exposure-reduction education, which all contribute to a higher risk of lead exposure.
6.3.6 LEAD METABOLISM
Lead enters the body via the mouth and the particles are solubilised (or digested) prior to absorption from the gut. Lead is best solubilised in highly acidic media (low pH) such as the fasting stomach environment. Lead absorption is reduced by preventing children from fasting because non-fasting stomachs have higher pH that is less conducive to absorption. All children are therefore encouraged to have breakfast and to snack between meals.
Lead solubilisation takes time. The extent to which a dose of lead becomes available for gut absorption depends on particle size (large particles take longer), lead type (oxides of lead solubilise
Appendix L ts and the extent to which a dose of of dose a which to extent the and h asmuscle and brain, and then into teeth gut motility. Some of the solubilised lead is is lead solubilised of the Some motility. gut but easier in children. Lead chemically chemically Lead children. in easier but and stores it in bone. Absorbed lead is excreted excreted is lead Absorbed bone. in it stores and nder is excreted in faeces. The extent to which which to extent The faeces. in excreted is nder lead toxicity. toxicity. lead blood and then rapidly transferred inside red be readily excreted. Lead is then slowly slowly then is Lead excreted. readily be lead excretion, unlike chemicals that stay in the the in stay that chemicals unlike excretion, lead bio-accessibility
is is stored in bone– it is nearly impossible adulin bio-availability. bio-availability. 5 July 2013 5 July
absorbed in the upper small intestine and the remai and pH, stomach ore–galena), lead than much faster its called is absorbed be to available made is lead serum(liquid partof the blood), and therefore can suc tissue soft into – firstly partitionedorgans various into Lead absorbed from the gut is transferred into the the into transferred is gut the from absorbed Lead further reduces markedly location This cells. blood lead is transferred into the blood is called its its called is blood the into transferred is lead (except during bone remodelling and osteoporosis), it absorbs body the why is which calcium, resembles by thekidney, making kidneythe targeta organ for and bones. It is difficult to extract lead once it it once lead extract to difficult is It bones. and
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7. RELATING AIR LEAD AND BLOOD LEAD IN PORT PIRIE
This section presents an analysis of blood lead and air lead data from Port Pirie and by including data from Teck and Umicore establishes a number of robust correlations.
A principal aim of the technology transformation is the reduction of lead emissions from the smelter and hence reductions in air lead concentrations in Port Pirie, which are regulated through Nyrstar’s environmental licence. All else being equal, there is a linear relationship between the annual lead emissions and annual average air lead concentrations. For example, halving lead emissions (from a fixed set of sources) will lead to a halving of air lead concentrations due to these sources. However, the relationship between blood lead levels and air lead concentration is somewhat more complicated.
The trend in blood lead levels in 1-4 year old children over the last 28 years in Port Pirie (Figure 28) shows a dramatic improvement since 1984 with an overall upward trend in the number of children with blood lead levels below 10 µg/dL, except for the period 2003-2005. However, currently there are still approximately 25% of children above 10 µg/dL.
Figure 28 Historical trend in Port Pirie blood lead levels represented by the proportion (percent) of 1–4 year old children <10 µg/dL.
Figure 29 shows the relationship between blood lead levels and air lead concentrations using data from Port Pirie (for 1-4 year old children) with air lead data from each of the licence monitoring sites,
Appendix L
3 he lines
s and annual average air lead concentrations lead concentrations air and annual average s pe and doublethe intercept. The reasons for he Umicore data also shows a good correlation correlation a good shows also data Umicore he ndenceon air lead concentrationsof the year old children). There is very close agreement agreement close very is There children). old year in Sections 6 and 8, it is not only the mean blood blood mean the only not is it 8, and 6 Sections in 10 µg/dL. The data is from the same sources as as sources same the from is data The µg/dL. 10 in than scatter greater is There levels. lead blood he guideline value of 10 µg/dL that is important important is that µg/dL 10 of value guideline he avenot been included in determining theoverall fit showing a slope of about 9 µg/dL per µg/m per µg/dL 9 about of slope a showing fit he Hoboken he population tothe smelter than at the gherdust deposition for givena APb at Hoboken (as olds), Trail (½–3 years) and Hoboken (2–6 years). T years). and (2–6 Hoboken years) (½–3 Trail olds), to the respective data. data. respective to the 5 July 2013 5 July Relation between geometric mean of blood lead level blood lead mean of geometric between Relation percentage of children with blood lead levels below er rath available), data only the was (this children l al for is data Hoboken the that except 29 Figure in than just younger1–4 year old children, thoseso h trends becauseolder children generally have lower from a health perspective. Figure 30 shows the depe the shows 30 Figure perspective. health a from based on historical data from Port Pirie (1–4 year year (1–4 Pirie Port data from on historical based 2008) (Cantrell fits bivariate are As mentioned in Section4and discussedmore fully lead levels butalso the numberof children belowt Figure 29. between the Port Pirie and Trail data with the best the with data Trail and Pirie Port the between Trail (children aged 6-36months) and Hoboken (2-6 noted in Section 5.3) and the closer proximity of t of proximity closer the and 5.3) Section in noted sites. two other and an intercept of BPb = 3–4 µg/dL when APb = 0. T = 0. APb when µg/dL 3–4 = BPb of intercept an and slo the double almost with but APb, and BPb between hi the to related possibly are but unclear are this
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Figure 29 but the trends are quite robust. The trend lines were determined using bivariate fits (Cantrell 2008), which allow for uncertainties in both variables. Extrapolating the Port Pirie and Trail curves to APb = 0 indicates that in these two towns adjacent to primary lead smelters we would still only expect about 95% of children to have blood lead levels below 10 µg/dL even if air lead concentrations were reduced to zero. The remaining 5% above 10 µg/dL probably reflects the residual background exposure due to legacy sources (see Section 6.3.3).
Figure 30. Relation between percentage of children with blood lead levels below 10 µg/dL and air lead concentrations based on historical data from Port Pirie (1–4 year olds), Trail (½–3 years) and Hoboken (all children).
The skewed nature of the blood lead distributions was shown for Trail data in Figure 15 and is shown more clearly for 2011 Port Pirie data in Figure 31. This figure also includes a log-normal fit, which is seen to fit the data extremely well. The geometric mean of 5.7 µg/dL is close to the peak in the distribution and the long tail to the right indicates that there is a small but non-zero probability of blood lead levels that are several times higher than the geometric mean.
Appendix L
bution. bution.
from Port Pirie children tested in 2011. Also Also 2011. in tested children Pirie Port from air lead concentrations and the fraction of the the of fraction the and concentrations lead air 9 and Figure 30.) Extrapolating the fits to the the to fits the Extrapolating 30.) Figure 9 and o predictions in Section 9 about the likely likely the 9 about Section in predictions o ansformation on blood lead levels. lead levels. blood on ansformation ident in the very high correlation in the data from data the in correlation high very the in ident eedances of 10 µg/dL if the geometric mean was was mean geometric the if µg/dL 10 of eedances iscombines the dataon geometricmeans and µg/dL in Hoboken. The strong correlation between between correlation strong The Hoboken. in µg/dL tionship between fraction of the population below a below population of the fraction between tionship well and emphasises the skewed nature of the distri nature the the of skewed and emphasises well 5 July 2013 5 July Frequency distribution histogram of blood lead data blood lead of histogram distribution Frequency
impact of the reduced emissions from the smelter tr smelter the from emissions reduced the of impact population below 10µg/dL, which gives confidence t Figure 31. rela is a linear there distributions For log-normal given value and the geometric mean. This is also ev also is This mean. geometric the and value given between link the demonstrates parameters two these data very the which fits fit, a lognormal is shown 2 Figure from µg/dL 10 below children of percentage exc few very be would there that indicates axis top about3 µg/dL Portin Pirie, 4 µg/dL Trailin and5 the each of the three sites shown in Figure 32. (Th 32. Figure in shown sites three the of each the
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Figure 32. Relation between percentage of children with blood lead levels below 10 µg/dL and geometric mean of blood lead levels based on historical data from Port Pirie (1–4 year olds), Trail (½–3 years) and Hoboken (all children).
Appendix L
d withother jurisdictions. Guidelines for and is likely to continue to be produced.This pulation since 1995. In these mitigation mitigation these In 1995. since pulation value was decreased to 10 µg/dL. The The µg/dL. 10 to decreased was value tories. These are in line with the the with line in are These tories. tralia has taken a balanced and measured measured and a balanced taken has tralia atters have moved to the need for control and and control for need the to moved have atters ing ing mined and thosein places where lead is over the years. In 1981 the value was 30 µg/dL, µg/dL, 30 was value the 1981 In years. the over sure and onthe basis of that developed a need for its extraction. This is not a new new a not is This extraction. its for need a the hazard does not translate into risk. Since Since risk. into translate not does hazard the use anxiety among the recipients of this of this recipients the among anxiety use in loweringin general population blood lead levels in levels of lead exposure. The guidelines are are guidelines The exposure. lead of levels in . This. emotive, pejorative language is unhelpful in tates and territories that then remain to be be to remain then that territories and tates in ourin bodiesor to have blooda lead the same will apply to Australia although no no although Australia to apply will same the e experienced increased exposure to lead. The The lead. to exposure increased e experienced
les and other forms of transport contain one or one contain transport of forms other and les 30years have diminished general urban and lead on focused has attention Inevitable e. ly insoluble and consequentially of limited y used when there is no evidence of any health health any of evidence no is there when y used d ubiquitously present ourin environment. For e presentationof informationon healthoutcomes us. We use lead in many ways, especially for lead- for especially ways, many in lead We use us. d hazard tothose carrying out the mining and mes associated with lead exposure and with the the with and exposure lead with associated mes gulations and legislation. 5 July 2013 5 July HEALTH OUTCOMES ASSOCIATEDLEAD WITH HEALTH EXPOSURE FRAMEWORK FOR MANAGING LEAD EXPOSURE EXPOSURE LEAD FOR MANAGING FRAMEWORK
associated language. An issue at present is that th that is present at issue An language. associated This section is a narrative to do with health outco health with do to narrative a is section This 8. 8.1 ca to calculated language used has exposure of lead information.The term ’lead poisoning’ is frequentl illness or syndrome clinical of form or any outcome National Health and Medical Research Council in Aus in Council Research Medical and Health National position onevaluation of the outcomes of leadexpo guidelines on the possiblehealth outcomesof certa terri and states the to recommendations as provided trying to deal with the real needs of those who hav who of those needs real the with deal to trying an Organization World Health of the recommendations be are ores lead-bearing where that places in means lea a be will there recycled and refined extracted, blood lead concentrations Australiain have changed re their into territories and states the by adopted an crust Earth's the in present element, an is Lead lead no have to impossible be would it reason that suburban the environmental as such exposure programs to leadMitigation thein world. developed succeeded have paint and petrol in lead of removal that One can assume world. the of parts various in measuresof change have madebeen thein general po programs the low-lying fruit has been plucked andm regulationof other less evident sourcesof exposur of lead. sources on geological areas and producing areores relative most lead-containing Fortuitously phenomenon.Lead has been producedsince antiquity which was lowered to 25 µg/dL in 1987. By 1993 the the 1993 By 1987. in µg/dL 25 to lowered was which s the to recommendations - that just are guidelines past the over taken Actions zero. of concentration is all around hazard lead However, bioavailability. vehic motor of majority The batteries. storage acid sound is containment the as long As batteries. more created we have lead use to decided has society our
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extraction and to those in close proximity to these operations. The hazard translates into risk when exposure is not managed adequately.
8.2 ENVIRONMENTAL JUSTICE
In the United States the EPA defines Environmental Justice thus:
‘Environmental Justice is the fair treatment and meaningful involvement of all people regardless of race, color, nationality, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. It will be achieved when everyone enjoys the same degree of protection from environmental and health hazards and equal access to the decision-making process to have a healthy environment in which to live, learn, and work.’
If a decision were made to transfer lead production to a developing nation from Australia a profound ethical issue would arise. As a developed nation we need lead as a commodity for our industrial base. We currently produce lead subject to increasingly rigorous regulation aimed at protection of the general population and the workers producing the metal. If production were transferred to a developing nation with less effective environmental regulation, either as part of legislation or through enforcement, we would carry the ethical responsibility for the populations involved as part of environmental justice. Advocates of environmental justice make the argument that socially disadvantaged populations often undertake environmentally hazardous activities because they have few economic alternatives and/or are not fully aware of the risks involved. Environmental issues have lesser importance in socially disadvantaged groups faced with pressing socio-economic issues such as income, education, nutrition and employment. Their voice is seldom heard on matters relating to the environment, as an extension of their lack of awareness of environmental justice. A combination of this lack of awareness and lack of political and economic power makes poor minority communities a frequent target for environmentally hazardous activities, which are also hazardous to their health.
Respect of equality of opportunity and protection of both humans and the environment in which they live enhances the environment’s ability to sustain human well-being. The nexus between health and wealth means that those who are relatively wealthy gain disproportionate benefits from the economic activities that degrade the environment, while those who are relatively powerless and poor typically bear disproportionate costs.
Appendix L
e and lead exposure below 10 µg/dL is difficult. difficult. is µg/dL 10 below exposure lead e defined clinical outcomes. Before blood blood Before outcomes. clinical e defined lable in which chelation therapy is only only is therapy chelation which in lable me reasonable expectation of exposure. of exposure. expectation reasonable me atter currently being evaluated by NHMRC NHMRC by evaluated being currently atter aemia can only start to be seen at relatively relatively at seen be to start only can aemia any detailed recommendationson this until ished in ished an individual, all potential aetiological bles the assessment of outcomes is categorised categorised outcomes is of assessment the bles elation. A hierarchical treatment and and treatment hierarchical A elation. individuals. of blood lead are derived from the various various the from derived are lead blood of d the National Toxicology Program (NTP 2012) in in 2012) (NTP Program Toxicology National the d /dL. The review carried out by the National National the by out carried review The /dL. ount in any of these descriptors of outcomes outcomes of descriptors of these any in ount ng the ng levelof epidemiologicalreliable evidence blood measurement.lead anyIn circumstances the 95th percentile of the population population the of percentile 95th the rried out in populations as epidemiological opulation,which lies above discrimination a limit. lead exposureon the basisof population norms. NTP there has been a shift away from the concept concept the from away shift a been has there NTP rim we note the following. Assessment of lead of lead Assessment following. the we note rim ement of blood lead. Hair lead measurement is of of is measurement lead Hair lead. of blood ement on-based approach, which has also been taken in ealth outcomes of lead exposure. Numerous articles articles Numerous exposure. of lead outcomes ealth imit is the 97.5th percentile of the population. Th population. the of percentile 97.5th the is imit The most recent are publications this year (2012) (2012) year this publications are recent most The r blood lead rangesof <5 and<10 µg/dL, in adults 5 July 2013 5 July A A DISTRIBUTIONAL APPROACH OUTCOMES, MANAGEMENT & TREATMENT OF LEAD EXPOSURE
It is notable that in the publications from CDC and CDC from publications the in that notable is It of absolute numerical guidelines to description of These population normsor population distributions 8.4 HANES) studies in USA. This approach remains remains approach This USA. in studies HANES) (N Survey Examination Nutrition and Health National populati This Australia. in use for evaluated to be p the of subset that identifying on relies Germany, (NHMRC2009). Itwould be inappropriateto provide at set been has limit discrimination the Germany In 8.3 m a is it exposure of lead treatment and Management inte the In completed. is review their as time such measur out by carried best is status individuals in ch by treated be not should exposure Lead value. no µg 15 than greater – concentrations lead blood high l the USA the In levels. lead of blood distribution management program for overexposure to lead is avai lead is to overexposure for program management ar there where circumstances extreme in implemented an and renal disease of as development such Changes ToxicologyProgram in USAis helpful in understandi lead measurements are undertaken there has to be so be to has there undertaken are lead measurements for indicators not are ADHD or IQ of low Diagnoses from outcomes health of measurement The (2012). USA ta summarial the In outcomes. these with associated as being ‘sufficient’, ‘limited’ or ‘inadequate’ fo where individual adverse health outcomes are establ are outcomes health adverse individual where factors should be considered. h the describe to section this in unnecessary is It detail. great in that just done have years past in an 2012) (CDC, Disease Control for Centres from the acc into taken be to has that aspect important most children. Without exception all the studies were ca were studies the all exception Without children. investigations. None were associated with change in change with associated were None investigations.
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from lead exposure is that all are derived from the epidemiological studies of very large populations. Information derived in this way gives guidance on acceptable levels in populations but cannot and should not be used in understanding of outcomes of lead exposure of individuals.
In pursuing a distributional approach of the nature described above, decisions have to be made at a political level on the proportion of the population that will be protected. As indicated above, the United States of America has adopted protection for 97.5% of the population. The distributions generated this way are always skewed (for example see Figure 15 and Figure 33), which means that arithmetic means of the blood lead concentrations in the population are inappropriate. For this reason geometric means, which more properly describe the peak of the distribution, have generally been adopted.
8.5 RELIABILITY OF MEASURES OF EXPOSURE AND OUTCOMES OF EXPOSURE
A key issue in understanding the relationships between exposure, outcomes and blood lead concentrations is that all of these measures have a substantial level of variance. Blood lead conventionally measured is likely to have a 10% or more variance on the laboratory results and probably more at the lowest levels of measurement. This would be combined with variance associated with sampling and personal physiology. IQ is a very imprecise measure and is normally broken down into different components all of which have substantial levels of variance. Exposure is a combination of a large number of different inputs, measurements of which has always been fraught with difficulty.
This tells us that we should not ascribe excessive levels of accuracy to relatively imprecise measures. More pertinently we should seek to make the action on exceedance of guidelines or other regulatory limits match the degree of over-exposure.
8.6 LEAD KINETICS
In describing the relationship between lead exposure and the body burden of lead, the assumption that the relationship is linear is incorrect. Blood lead concentrations are taken as a surrogate measure of body burden. Most studies have shown that the relationship is non-linear, with the greatest rate of change in blood lead being observed at the lowest levels of exposure. This is true for both gastrointestinal exposure and pulmonary exposure. There is a complex relationship between vectors of lead exposure and the bioavailability of the different lead species in the source.
Appendix L
lity but would 3 hat all lead in the air will exist as particles of of particles as exist will air the in lead all hat to follow non-linear relationships. It is thus thus is It relationships. non-linear follow to tural and anthropogenic (see section 6.3.3). 6.3.3). section (see anthropogenic and tural er there are multifactorial drivers of drivers multifactorial are there er loped for a large population to describe to describe population large a for loped insufficiency, especiallydeficiency iron (see ganisms and various biochemical outcomes is outcomes biochemical various and ganisms particularly fraught association. Increased lead lead Increased association. fraught particularly satiety state of the individual. Gender and age age and Gender individual. of the state satiety lead exposure from the air and blood lead is is lead blood and air the from exposure lead rise but are not tied to any clinical changes at at changes clinical any to tied not are but rise d graphs of log/linear relationships which place the presence of lead. Its activity decreases decreases activity Its of lead. presence the the same gastrointestinal absorption route as as route absorption gastrointestinal same the t is also inappropriate to use these these to use inappropriate also t is ed at very low levels of lead exposure but in in but exposure of lead levels low very at ed ion of gastrointestinal lead is very variable, from very variable, is lead gastrointestinal of ion residual a be still will there 0 near to reduced be Such particles Such a have relatively high bio-availabi al outcome. For example the enzyme 5- enzyme the example For outcome. al Pirie. Port for 29 Figure in shown as µg/dL 3 round through the upper respiratory tract to the deep deep the to tract respiratory upper the through ssible tomeasure changes longin nerveconduction the general population other factors are probably probably are factors other population general the to lead smelters. This relationship would suggest suggest would relationship This smelters. lead to h a h gradient of around9µg/dL per µg/m onmental levels of exposure the inhibition is not not is inhibition the exposure of levels onmental tical. Lead species are not gaseous or liquid or liquid gaseous not are species Lead tical. h children and women in their childbearing years 5 July 2013 5 July LEAD IMPACTS ON BIOCHEMISTRY & INTELLIGENCE
suggest that even if air lead concentrations could could concentrations lead air if even that suggest na both - sources other from exposure of background
8.7 The relationship between the presenceof lead in or observ be often can effects These curvilinear. also outcomes in any individual. a is IQ and exposure lead between relationship The general are not associated with any specific clinic specific any with associated not are general to sensitive is highly dehydratase aminolaevulinate epidemiological relationships, which have been deve exposure does contribute to diminution in IQ. Howev cri size is particle lead, to exposure For airborne (excepting some alkyl leadcompounds) which means t can pass particles smallest the Only sizes. various absorption. potential for alveoli lung of the space envir At rise. concentrations as lead curvilinearly po also is It outcome. clinical any with associated concentrations lead as slowed are which velocities, also e IQ follow chang non-linear relationships.of The lead-related that measures unsurprising an 100 is population any for IQ for value normative I inappropriate. are 100 than greater intercept the in exposure lead of levels current At intelligence. environmental exposure levels. These too would seem would too These levels. exposure environmental Larger particles are likely to be swept by muco- by swept be to likely are particles Larger ratio. volume to area surface high of their because ciliary action intothe oesophagus and there follow absorpt of rate diet. The in materials lead-bearing are also drivers of the bioavailability of lead wit of lead ofbioavailability the aredrivers also less than1% to 20+%, andhighly contingent onthe mineral of lead because more absorb to more likely section 6.3.5). 6.3.5). section On an international basis the relationship between all proximal sites of different a number similar at that there is an intercept on the blood lead axis a axis lead blood the on intercept an is there that wit is fairly shallow relationship the of The graph
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more important in development of intelligence. In particular environment, genetic background, education, nutrition, gestation and birth weight are all material factors in development of IQ pre-and post-natally. The same applies to exposed populations in whom lead is another factor in development of intelligence.
8.8 THE HISTORICAL BACKGROUND IN PORT PIRIE
In the particular circumstances of Port Pirie, examination of lead exposure and blood lead concentrations has been pursued over many years. The record from 1984 onwards shows a continuous downward trend in mean blood lead concentrations. This is consistent with the continued attention to minimisation of exposure and mitigation of effects of exposure. The various curves in Figure 33 describe the distribution of blood lead concentrations in Port Pirie in
• 1984, • 2011, • post-introduction of new technologies for lead smelting, and • distribution in a population of infants in NSW described by (Gulson, et al. 2008).
The distributions demonstrate that in 1984 most subjects exceeded 10 µg/dL but at that time the guidance value was higher (30 µg/dL). The situation now shows that about 25% of the population have blood leads greater than 10 µg/dL. This is consistent with the process of continuous improvement over the past 27 years. The projected situation post-transformation suggests that there would still be some subjects with blood lead concentrations greater than 10 µg/dL. This takes into account residual non-airborne exposure resulting in mean blood leads of about 3 µg/dL (see Figure 29). If further actions are taken to minimise these parallel routes of exposure there could be further diminution in the percentage of subjects with blood lead greater than 10 µg/dL.
In a continuous distribution it is obvious that in the ‘tail’ of values, even for a suburban population in NSW (far removed from a lead smelter), some will have BPb > 10 µg/dL. A corollary to this is that the discrimination limits of 30 µg/dL in 1984 and 10 µg/dL presently are not descriptors of health outcomes. A shift from 9 µg/dL to 11 µg/dL does not imply a sudden shift of health outcomes, merely a 2 µg/dL change in BPb in a continuum of change.
Appendix L
s for Port Pirie in 1984, now (2011), and (2011), now 1984, in Pirie Port for s iate educationand training givenon matters n by USA the 97.5th percentile might be used. used. be might percentile 97.5th the USA by n y being collected. The need now is to define the the define to is now need The collected. being y reasons for individual excess exposure and on of metals. Such factors need to be actively actively be to need factors Such metals. of on action to mitigate lead exposure should be be should exposure lead mitigate to action indicated previously, gender and age are drivers drivers age are and gender previously, indicated to other vectors. These are not the only potential potential only the not are These vectors. other to rticularly important and in some circumstances circumstances some in and important rticularly cheme of management of exposure, a shift from from shift a of exposure, management of cheme bgroup of the population whose blood lead lies s merit. The data for Port Pirie occupational occupational Pirie Port for data The merit. s n Sydney population. population. n Sydney 5 July 2013 5 July Schematic representation of blood lead distribution representation blood lead of Schematic A A DISTRIBUTIONAL APPROACH AND SUBSEQUENT MANAGEMENT
projected Post-transformation, compared with a urba with compared Post-transformation, projected 8.9 s rational a place in put to and change evaluate To Figure 33 arbitrary guidelines to population distributions ha is alread exposure population general and exposures % point in the distributionabove whicha scheme of implemented. Forconsistency with theapproach take su the with deal to action for need a then is There As concentrations. lead blood increased for reasons of absorption.Mineral balance and nutrition are pa hyper-absorpti to may contribute altered physiology outsidethe desired97.5% population envelope. The absorption needto be sought and managed by appropr exposure and dust to exposure hygiene, to relating
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sought and managed in the individual to minimise their uptake of lead. Experience has shown that the outcome of lead mitigation measures takes some time to become evident. It is important both politically and publicly to make this clear since impatient demands for instant outcomes are unlikely to be realised.
Appendix L o osure of the Cockle Creek smelter smelter Creek Cockle the of osure nce 2005nce withthe ‘Ten by 10’ and chnologies (SKS) and they advised that it is is it that advised they and (SKS) chnologies fume reduction using surplus baghouse ative impacts on the socio-economic and hence hence and socio-economic the on impacts ative nd annd understanding ofthe other sources, it environment would be required to reduce all sulated bath smelting technology. EHWP EHWP technology. smelting bath sulated th performance post-transformation, it is useful is useful it post-transformation, performance th issions from the smelter site by more than 50%. 50%. than more by site smelter the from issions quo)or smelterclosure. ams have seen actionon bothexposure reduction rie smelter is the sinter plant. Nyrstar proposes t Nyrstar proposes sinter plant. the smelter is rie current dominance of sinter plant emissions emissions plant sinter of dominance current ous improvements described in Section 3.3 (e.g. (e.g. 3.3 Section in described improvements ous were still 7% of young children above 10 µg/dL. µg/dL. 10 above children young of 7% still were more, although not considered in this report, report, this in considered not although more, continues to contribute to children’s exposure. exposure. children’s to contribute to continues class of enclosed bath smelting technologies. technologies. smelting bath enclosed of class rther improvements in air leadand blood lead mated that the transformational upgrade of the the of upgrade transformational the that mated ce by more than 50%. In the following, we assume we assume following, the In 50%. than more ceby s replaced with modern technology. technology. modern with replaced s Results on blood lead reductions following the cl the following reductions lead blood on Results The improvements in blood lead levels achieved si achieved levels lead blood in improvements The 5 July 2013 5 July LIKELY POST-TRANSFORMATION PERFORMANCE INTRODUCTION INTRODUCTION POST-TRANSFORMATION PERFORMANCE PERFORMANCE POST-TRANSFORMATION
9.2 Pi Port the at emissions of lead source primary The to note the outcomes from continuing as-is (status (status as-is continuing from outcomes the to note Before describing the likely environmental and heal 9. 9.1 Status quo. air halved approximately have latter The plant. the from reductions emission and community the in the but 19) (Figure 2005 since concentrations lead fu marginal only to 2 points Section in highlighted levels being possible untilthe aged sinter plant i Smelterclosure. approximately 25% of children still have blood blood have still of children 25% – approximately off level to started have programs Them’ for ‘Ten progr These 28). (Figure µg/dL 10 above levels lead sformation of the sinter plant with further further with plant sinter of the sformation tran technology the to due reduction 50% initial an reductionsoccurring as a resultof ongoing continu pit remediation, improvedconcentrate handling and replace the existing sinter plant with modern encap modern with plant sinter existing the replace general the in practice of best example fide’ ‘bona redu also will concentrations lead air that follows smelter closure would be likely to have extreme neg extreme have to likely be would closure smelter te these of newest the review to CSIRO commissioned esti is 2 it Section in described work the on Based sinter plantwill reduce amountthe of lead dust em Basedon standard dispersionmodelling principles a Thus, even with smelter closure, remediation of the of remediation closure, smelter with even Thus, Further level. acceptable an to exposure children’s residents. Pirie Port of outcomes health This is because lead from soil and house reservoirs house and soil from lead This is because (Figure 22) show that even after three years there there years three after even that show 22) (Figure
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capacity). It is estimated that over the next 10 years this is likely to produce total reductions of 75% of current values.
Observations by the EHWP of best practice smelters (in Belgium and Canada) summarised in Section 4.3 show that a halving of air lead concentrations took from 1–4 years (Figure 16) so we have assumed an average of these figures for the Port Pirie transformation. These estimates have been used to show the projected reductions schematically in Figure 34. Current annual average air lead concentrations of about 0.4 µg/m3 at licensed EPA monitoring sites will drop to 0.2 µg/m3 over a couple of years with further reductions during the decade to possibly produce values as good as 0.1 µg/m3. The EHWP believes that an annual average of 0.2 µg/m3 could be achieved consistently while 0.1 µg/m3 could be achieved much of the time but not consistently.
Figure 34 Schematic diagram of projected reductions in air lead concentrations at EPA licensed monitoring sites (Oliver Street and Pirie West Primary School) following the introduction of EBS (encapsulated bath smelting) technology in 2016 and implementation of a continuous improvement program.
Using the results presented in Figure 30, we can estimate that a reduction of annual average air lead concentrations to 0.2 µg/m3 will increase the percentage of children with blood lead levels below 10 µg/dL from the current value of about 70-75% to about 85%. However, as shown in Figure 17 for other best practice smelters, the timescale for blood lead reductions is longer, typically 7-9 years.
Appendix L
for air lead, for air 3 ge of children with blood lead levels below below levels blood lead with children of ge ram, a large percentage of the population population the of percentage large a ram, lustration in Figure 35 of the projected projected of the 35 Figure in lustration changes in the blood lead distributions using
ove the NHMRC recommendation to around 40 40 around to recommendation NHMRC the ove et the aspirational goal of 0.1 µg/m 0.1 of goal aspirational the et a decade after the transformation. This equates equates This transformation. the after decade a 0 µg/dL reach 85-90% about 8 years after the 8 after years about 85-90% reach µg/dL 0 from those reported from urban Sydney in 2006. 2006. in Sydney urban from reported those from ed levels below 10 µg/dL. µg/dL. 10 below levels ed mpact of the transformation on blood lead levels levels lead blood on transformation the of mpact These projections show that with the the with that show projections These am. lated bath smelting) technology in 2016 and 2016 in technology bathlated smelting) 5 July 2013 5 July Schematic diagram of projected increase in percenta in increase diagram projected of Schematic to a decrease from around 200 children currently ab currently children 200 around from decrease to a program described in Section 9.3 are 9.3 are Section in described program abatement lead community targeted the with together 1 below children of percentage the see to projected 95% about to increases further with transformation transformation. the after decade a children implementation of the targeted lead abatement progr abatement lead targeted the of implementation 10 µg/dL following the introduction of EBS (encapsu EBS of introduction the following µg/dL 10 In orderto provide a better understanding ofthe i projected the shows 36 Figure community, the within different no are that levels lead blood have would Figure 35 the results of the analyses presented in Section 7. Section in presented analyses of the results the prog abatement lead targeted the and transformation il schematic the to produce used were numbers These increase thein percentageof childrenwith blood l Further targeted projects to reduce emissions to me to emissions reduce to projects targeted Further
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Following the transformation, there will still be some contamination from other smelting site sources, such as the Slag Fumer, and therefore ongoing smaller-scale upgrades will be required. However as air quality improves (post-transformation) it is unlikely that further CAPEX will bring about another step-change in blood lead levels as the contamination from historical sources of lead will become a relatively larger part of the ‘residual exposure’.
Figure 36 Schematic of current and projected blood lead distributions in Port Pirie compared with distribution among children in Sydney in 2006 (Gulson, et al. 2008).
9.3 TARGETED LEAD ABATEMENT PROGRAM
In order to manage this ‘residual exposure’ risk, Nyrstar and the South Australian Government have established a working group to develop objectives and recommendations for the implementation of a new Targeted Lead Abatement Program (TLAP) in Port Pirie.
The TLAP working group will identify current and potential future community lead exposure reduction strategies and assess which are likely to have the greatest impact in reducing children’s
Appendix L notified industrial DARDS limit was also applied 3 in January 2005. A A 2005. January in (12 month average) and and average) month (12 3 3 at all Australians should have blood lead have blood should at Australians all e blood lead reduction program has been the sue the TLAP for a period of 10 years in order order in years of 10 period a for TLAP the sue eing the numerous work streams that need to to need that streams work numerous the eing nication and communityengagement tothe proposed construction and d the most recent ‘Thumbs up for low levels’. levels’. low for up ‘Thumbs recent most the d gies will continue post commissioning to to commissioning post continue will gies l bel engagedto provide input intothe onsidered a natural progression of these nging environmental conditions thein r implementation by the Port Pirie Pirie Port the by implementation r be vital. vital. be s reduced to 0.5 µg/m which time the 0.5 µg/m 0.5 the time which ct to proceed. Leading up to this milestone, milestone, this to up Leading to proceed. ct During this time the program will need to be be to need will program the time this During for air lead is 0.5 µg/m 0.5 air lead is for mostin of Europe(but see below forGermany) d ensure the transformation objectives are met. met. are objectives transformation the ensure d ich it expects to complete by late 2013 or early early or 2013 late by complete to expects it ich here here have been three community blood lead ureto lead shouldminimised. be NHMRC is e transformation project and the subsequent subsequent the and project transformation e orking group is to provide details ofthe proposed was applied in the immediate vicinity of specific, of vicinity immediate the in applied was 3 5 July 2013 5 July LIKELY PERFORMANCE COMPARED WITH INTERNATIONAL STAN
sources from January 2005 until January 2010, after 2010, January until 2005 from January sources Prevention recommendation of 10 µg/dL (US (US µg/dL 10 of recommendation Prevention and Control Disease for Centers US 2005 follows the 2005). CDC to these sources. The blood lead intervention level intervention lead blood The sources. these to cornerstone of its success since 1984. Since 2006 t 2006 Since 1984. since success its of cornerstone constantlyevaluated andmodified to respond to cha community during and post-transformation. Community engagement and ownershipof the Port Piri an Them’ For ‘Ten 10’, by ’Ten campaigns, awareness c is Program Abatement Lead Targeted Pirie Port The of th success the to critical and programs previous regarding the TLAP process and implementation will will implementation and process TLAP the regarding pur to commitment a made have State the and Nyrstar program. ofthe objectives term long the to achieve reduction communityin blood lead levels. up lead the in 2014 in commence to expected is TLAP minimise exposure to historical lead disposition an developmentof TLAP. In this process,ongoing commu Strate 2016. in technology new of the commissioning 9.4 (NEPM) standard quality air Australian The current be delivered by the endof 2013 to enablethe proje wilof areas range from a key stakeholders numerous program and its implementation for consideration fo overse group the Committee, Steering Transformation w TLAP the for milestone first A levels. lead blood transitionary value of 1.0 µg/m 1.0 of value transitionary the current NHMRC recommendation (NHMRC 2009) is th is 2009) (NHMRC recommendation NHMRC current the levels below10 µg/dL andthat all children’sexpos currently undertaking a reviewof its guidelineswh 2014. 2014. wa Europe in average) (annual standard The air lead
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The US EPA introduced a new air quality lead standard in 2008 of 0.15 µg/m3 (rolling 3-month average). This replaced the 1978 lead standard of 1.5 µg/m3 (quarterly average) (USEPA 2008), although there was a transitionary arrangement for areas designated nonattainment for the 1978 standard, that the 1978 standard remained in effect until implementation plans to attain or maintain the 2008 standard were approved. However, this new standard drove the closure (slated for the end of 2013) of the last lead smelter in the US (Herculaneum).
The US Centers for Disease Control and Prevention (CDC 2012) recommended in 2012 that its previous recommendation of 10 µg/dL be replaced by a reference value based on the 97.5th percentile of the blood lead levels of children 1-5 years old (currently 5 µg/dL), which should be used to identify children with elevated blood lead levels for whom public health actions should be initiated. They noted that there are currently approximately 450,000 US children above this reference level.
In Germany a reference value of the 95th percentile has been set, which is currently 3.5 μg/dL for children aged 3-14 years, 7 μg/dL for women and 9 μg/dL for men. There are currently approximately 400,000 German children aged 3-14 years above this reference value.
In summary, the worldwide trend is to continue to drive blood lead levels down further. However, as discussed in Section 8, at blood lead levels below 10 µg/dL, the health outcomes from lead exposure are all derived from epidemiological studies of very large populations, and cannot be used in understanding the outcomes of lead exposure of individuals. Certainly the term ‘lead poisoning’ is inappropriate when there is no evidence of any clinical syndrome or illness; there is need to try and move the media away from this term to one of ‘acceptable levels’ with ‘minimal effects’.
Appendix L n
ildren ofildren PortPirie 12 months). at the licensed monitoring monitoring licensed the at 3 (consistently)and therewill be 3 ), factorsother than the reduced 3 mation occurs. occurs. mation to 0.3-0.4 ug/m 0.3-0.4 to t Port Pirie, we can expect air quality to to quality air expect can we Pirie, Port t and backtracking analysis from Port Pirie Pirie Port from analysis backtracking and 3 concentrations in Port Pirie by an average of average an by Pirie Port in concentrations of 0.2 ug/m 0.2 of toric lead contamination, play a more significant significant more a play contamination, lead toric air lead concentrations within 1-4 years years 1-4 within concentrations lead air about 85-90%. 85-90%. about ologies will aperform tohigh environmental toreplace the sinter plantwith modern best ldren in thecommunity. tion is significantly skewed such that there may may there that such skewed significantly is tion ver, with more than 50% of current lead dust dust lead current of 50% than more with ver, endemonstrated that thesinter plant (and ren withren blood levelslead µg/dL 10below will tedthat there wouldonly marginal be further lities are properly retro-fitted. show that we can expect that reducing air lead lead air reducing that expect can we that show echnologies are usedworldwide including KIVCET, f the health guideline (the ‘tail’). We expect that expect We ‘tail’). (the guideline health the f a series of improvements (mainly as part of the ‘Te the of part as (mainly improvements of series a 50% of air lead emissions from the smelter – the the – smelter the from emissions lead air of 50% will reduce the geometric mean of blood lead in ch in lead of blood mean geometric the reduce will 3 will be achieved (but not consistently over a full a over consistently not (but achieved be will 3 5 July 2013 5 July CONCLUSION
11% p.a. over the last decade, from around 0.8 ug/m 0.8 around from decade, last the over p.a. 11% by 10’ program) has reduced annual average air lead average annual reduced has by 10’ program) over the next 8 years or so the percentage of child of percentage the or so years 8 next the over to 70-75% about of value current the from increase (below 0.2 further are reduced ug/m concentrations As air lead . While the mean blood lead level is indicative of of indicative is level lead blood mean the While . years 8 next the about over 4 ug/dL to ug/dL 6 from overall performance, the distribution in the popula still be significanta number ofchildren outsideo improve to an annual average air lead concentration lead air average annual an to improve following commissioning. Following transformation a A review of best practice technologies at smelters in Belgiumsmelters and at Canadashowed that technologies their practice of best review A average halved at least transformations technology emissions coming from the sinter plant, it is expec is it plant, sinter the from coming emissions transfor technology proposed the until improvements sites at Pirie West Primary and Oliver Street. Howe Street. Oliver and Primary West Pirie at sites Analysis of data from Trail (Canada) and Port Pirie Port and (Canada) Trail of data from Analysis 0.2 ug/m to concentrations
10. to of lead emissions order reduce to in Pirie Port at smelter the transform to requirement a is There air and hence reduce blood lead levels in young chi be has 2, it Section in described work the on Based associated activities) is responsible for at least least at for is responsible activities) associated evidence comes from bothfugitive emissions studies sites. monitoring is transformation of the premise key the Therefore y, thereby eliminating the major source of of source major the eliminating thereby y, technolog (EBS) smelting bath encapsulated practice t practice of best range A emissions. lead fugitive techn these of All SKS. and ISASMELT, Outotec, QSL, standard as long as best practice gas handling faci handling gas practice best as long as standard that shows Pirie Port at data quality air Historic periodswhen 0.1 ug/m emissions from the transformed smelter, such as his as such smelter, transformed the from emissions
5 July 2013
role. Thus a targeted lead abatement program is recommended to manage this ‘residual exposure’ risk.
With ongoing improvements to the plant to reduce emissions to meet the aspirational air lead goal of 0.1 µg/m3, the targeted community lead abatement program described in Section 9.3 is projected to see the percentage of children below 10 µg/dL reach 95% about a decade after the transformation. This equates to a decrease from around 200 children currently above the NHMRC recommendation to around 40 children a decade after the transformation.
While the objective of the targeted lead abatement program should be to ensure that all children are below the guideline, the reality is that even in a suburban population (such as Sydney) a small number of children will still be above the guideline. At this stage there is a need to shift the management of blood lead levels from guideline values to a ‘distributional approach’ such as that recently adopted in the US and Germany. In the meantime, a focus on mean blood lead improvements and a targeted program for the children who continue to have higher blood lead levels (post-transformation) is the way forward for Port Pirie.
The next steps require preparation of the Engineering Feasibility Study, Environment Improvement Program, Targeted Lead Abatement Program and Development Assessment reports. They all rely on the concepts and principles outlined in this document – the Environment and Health Feasibility Study – and further work should ensure that they build on these concepts. In some cases further work will lead to increased confidence around the concepts put forward however it is unlikely that this will lead to substantial changes in the projections for air quality and blood lead levels.
Appendix L
d- Focus
/pdf/teck-cominco.pdf, ct Hoboken,ct Wijk -focus-06.pdf, 2005. 2005. -focus-06.pdf, a from Port Pirie Monitoring Sites. Monitoring Pirie Port from a
in children from Hoboken). all for Primary Prevention. Report of the the of Report Prevention. Primary for all pdf, 2012, 65. 65. 2012, pdf, pdf, 2011. 2011. pdf, ondheid/zware_metalen/, 2005-2012. 2005-2012. ondheid/zware_metalen/,
ns/new36new37. ns/new36new37. 8 (2008): 5477–5487. 5477–5487. (2008): 8 _html;www.eea.europa.eu/data-and- -6. ention. 12. Base.” 2012. 2012. Base.” or andor routes of leadexposure in pregrasping quares fitting of data and application to to application and of data fitting quares tedelements bloodin of healthy young children.” Provinciaal Instituutvoor Hygiëne, Profiles on remediation projects - Teck Cominco Lea Cominco Teck - projects remediation on Profiles 22 (2008): 206-214. 206-214. (2008): 22 The Port Pirie Lead Implementation Program: Future Future Program: Implementation Lead Pirie Port The 14, no. 4 (2004): 14: 300-311. 300-311. 14: (2004): 4 no. 14, Atmos. Chem. Phys. Bevolkingsonderzoek blood. lood Antwerpenin Distri www.env.gov.bc.ca/epd/remediation/project-profiles www.health.sa.gov.au/pehs/PDF-files/ptpirie-future Preliminary Analysis of meteorological and Lead Dat 5 July 2013 5 July Loodgehalten bij kinderen uit Hoboken (Lead levels levels (Lead Hoboken uit kinderen bij Loodgehalten J Exp J Exp Anal Environ Epidemiol Low Level Lead Exposure Harms Children: A Renewed C Renewed A Children: Harms Exposure Lead Level Low REFERENCES REFERENCES
Zinc Smelter, Trail,BC. Smelter, Zinc 11. data quality European Air the 6 - “AirBase AirBase. http://acm.eionet.europa.eu/databases/airbase/index maps/data/airbase-the-european-air-quality-database British ColumbiaMinistry of Environnment. 2009. 2009. least-s linear methods for of “Review Cantrell, CA. problems.” chemistry atmospheric CDC. Advisory Committee Childhood Lead on PoisoningPrev J. J. Trace Elements Medicinein and Biology infants.” CSIRO, 2012. 2012. CSIRO, Kranz B., SimonD.L., andLeonardi B..“ The behavi and Directions. Nelen, V. www.cdc.gov/nceh/lead/ACCLPP/Final_Document_030712. CDC,.“Update onBlood Lead Levels Children.”in 20 www.cdc.gov/nceh/lead/ACCLPP/blood_lead_levels.htm. Gulson, B, etal. “Longitudinal monitoringof selec Hibberd, MF. www.provant.be/leefomgeving/onderzoek/milieu_en_gez Thys. G and V, Nelen, Moretusburg-Hertogvelden. Verslag najaar 2011. www.provant.be/binaries/HobokenNJ11_tg_tcm7-145267. NHMRC. 2009.www.nhmrc.gov.au/guidelines/publicatio Maynard, EJ, LJ Franks, and MS Malcolm. MS and EJ, LJ Franks, Maynard,
5 July 2013
NHMRC,. “Blood lead levels for Australians - Information Paper.” 2009a. www.nhmrc.gov.au/_files_nhmrc/publications/attachments/gp2-lead-info-paper.pdf.
NOHSC. National Standard for the Control of Inorganic Lead at Work; NOHSC:1012. National Occupational Health and Safety Commission, ww.safeworkaustralia.gov.au/sites/swa, 1994.
NTP. “NTP Monograph on health effects of low-level lead.” 2012. http://ntp.niehs.nih.gov/NTP/ohat/Lead/Final/MonographHealthEffectsLowLevelLead_prepublicatio n_508.pdf.
Ohmsen, G. Bio-accessibility of Pb, AS and Cd in smelter materials and indoor air-fall dusts. SA Department of Health, 2006.
PAE Holmes. “Nyrstar Port Pire - Fugitive metals emissions study.” 2012.
Simon, D L, E J Maynard, and K D Thomas. “Living in a Sea of Lead - Changes in Blood and Hand Lead of Infants Living Near a Smelter.” J Exp Sci Environ Epi 17 (2007): 248-259.
SKM. “Fugitive Particulate Emission Study, Pasminco Port Pirie Smelter.” 1999.
THEP. “Fall 2011 Blood Lead Report.” 2011. www.thep.ca/upload/resources/13/fall11bloodlead_original.pdf.
US CDC. Preventing lead poisoning in young children. www.cdc.gov/nceh/lead/publications/prevleadpoisoning.pdf, 2005.
USEPA. Lead air quality standards. 2008. www.epa.gov/air/lead/standards.html.
USEPA. “Review of the NAAQ standard for lead: policy assessment of scientific and technical information OAQPS Staff Paper: EPA-542/R-07-013.” 2007, 5-16.
VMM. Studie van de luchtverontreiniging in de omgeving van de Umicore vestiging in Hoboken; Jaarrapport 2009. http://publicaties.vlaanderen.be/docfolder/21170/rapport_Hoboken_2009.pdf, 2009.
Nyrstar Port Pirie Smelter Transformation Proposal Public Environmental Report