Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | - 3 − ffi as an an- 5 . Chemistry 2 and Physics Discussions in Birmingham Atmospheric 3 − for PM 3 − . In the European Union, is readily determined, it is 1 10 5 . 2 and PM 5 . , and J. Yin 2 1 6806 6805 , L. Hu 1 in London, well below concentrations typical of other 3 − , D. C. S. Beddows in London. Concentrations were highly correlated between two Lon- 1,* 3 − This discussion paper is/has beenand under Physics review (ACP). for Please the refer journal to Atmospheric the Chemistry corresponding final paper in ACP if available. National Centre for Atmospheric Science, Division of Environmental Health & Risk also at: Centre of Excellence in Environmental Studies, King Abdulaziz University, P.O. Box the years 2009–2011 (Harrisonsuch et as al., sulphate 2012). and nitrate While to the concentrations contribution of of components PM 1 Introduction The enforcement of legislationtions internationally of is particulate acting to matter,member reduce states measured airborne have as to concentra- PM nual meet mean an by air 2015, quality asmagnitude objective well depends of as upon 25 an µg the exposure m reduction annual target average to concentration be across met qualifying by sites 2020 in whose of potassium-rich emissionsand amounting 0.30 to µg m andon estimated sites 0.08 separated µg m by 4ble. km Data suggesting from that the an aethalometerhigher advected are concentrations, regional depending either source upon supportive is the of responsi- way these in conclusions which or the suggest data are analysed. published data. It iswood concluded stoves that and there fireplaces maylevoglucosan, with be the a two other distinct from high source larger,ciency, organic best modern types, carbon represented appliances one content, by with from potassium. best aa represented very Based conversion high upon factor by of levoglucosan burn-out concentrations 11.2 e trations and from of wood levoglucosan smoke to including wood winterin smoke and Birmingham mass, summer and sampling average periods concen- 0.33 µg arenorthern 0.23 m µg European m urban areas. There may be a further contribution from sources Airborne concentrations of thehave wood been smoke measured tracers, levoglucosan at andsurements urban fine with and potassium a rural multi-wavelength sitesin aethalometer. in cities, The show the low UK United ratios sites, Kingdom of and levoglucosan alongside especially to mea- potassium those in comparison to the majority of Abstract 1 Management, School of Geography, EarthBirmingham, & Edgbaston, Environmental Birmingham Sciences,* University B15 of 2TT, UK 80203, Jeddah 21589, Saudi Arabia Received: 13 January 2012 – Accepted:Correspondence 7 to: February 2012 R. – M. Published: Harrison 5 ([email protected]) MarchPublished 2012 by Copernicus Publications on behalf of the European Geosciences Union. Comparison of methods for evaluationwood of smoke and estimation ofambient UK concentrations R. M. Harrison Atmos. Chem. Phys. Discuss., 12,www.atmos-chem-phys-discuss.net/12/6805/2012/ 6805–6838, 2012 doi:10.5194/acpd-12-6805-2012 © Author(s) 2012. CC Attribution 3.0 License. 5 20 25 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | c ffi culty during ffi c to PM 3 − ffi respectively 3 cients (i.e. the − ffi culties, most estimates of ffi cient). This assumption may ffi erence between seasons. These estimates, ff 6808 6807 mass were only 0.07 and 0.06 µg m erentiated from their Angstrom coe 5 ff . cult to quantify by receptor modelling, and for which erent geographic areas in which measurements were 2 ff ffi cult due to the inhomogeneity of soils and hence the di ffi er substantially in composition dependent upon the source area. A ff cult to quantify the contributions of primary sources such as road tra ffi In this study, we report measurements of the wood smoke tracers levoglucosan and There have been few studies of the source apportionment of particulate matter in the Fine particle soluble potassium has also been recommended as a wood smoke Since the estimation of emissions poses such large di Amongst the sources most di fine K at a number ofsmoke, UK which locations. are These compared are witha used to multi-wavelength estimates aethalometer. estimate derived concentrations from of simultaneous wood deployment of 2 Experimental Four air sampling sites were used as follows: area showing estimated wood smokewinter. concentrations of Even, approximately 3 allowing µgan m for inter-laboratory a comparison, divergence there ofunlikely remains to a a be factor explained very by of large themade. approximately di discrepancy two which revealed seems by method under other circumstances has not been systematically explored. UK atmosphere. Yin etrange of al. organic (2010) source tracers applied including acontributions levoglucosan. to CMB Their annual estimates model of mean wood to PM smoke for chemical urban and data rural including sites, with a measured rather little in di the UKFuller et West al. Midlands (2011) area, based are upon in levoglucosan concentrations sharp measured contrast in to the London data reported by upon the assumption thatand elemental wood carbon smoke, arises which may fromwavelength be only di dependence two of sources, the roadbe tra optical correct in absorption Swiss coe valleysthe under the method atmospheric was inversion conditions developed prevailing (Sandradewi when et al., 2008a,b), but the applicability of the or multi-wavelength aethalometer (Sandradewi et al., 2008a,b). This method depends third method for estimating wood smoke concentrations is based upon use of a dual, tracer (Chow et al.,of 2007). a If source profile itsea in is salt a to and CMB be soil model, usedreliably to then as in airborne most it a situations potassium must specific based be (K).contribution tracer, upon corrected is While as measurements for more the of opposed the di sodium, former to correctionof contributions can part for of taking be the soil soil achieved rather samplessoil tracer. which Soil give in aand the may relevant fine hence ratio particle di of fraction may K/Ca have to travelled for permit significant use distances of Ca as a but the ratio of levoglucosanthe to specific wood wood smoke mass type2007). is being Nonetheless, highly burnt levoglucosan variable, has and dependingwood upon been smoke the widely to combustion organic used conditions carbonCaseiro to (Puxbaum et and estimate al., to et contributions 2009). wood of al., smoke mass (e.g. Puxbaum et al., 2007; factors are highly variable dependingcombustion upon practice adopted the (Kelz type et of al., combustion 2010; appliance, Pio or et open al.,the 2008). source contribution arebased based upon upon a receptor CMB(e.g. modelling modelling Chow methods. approach et using These al, aof may 2007), range studies be of or have compositional measured morecomponent. components anhydrosugars, often of upon This which individual levoglucosan method source is appears tracers. the to predominant The be majority relatively specific to biomass combustion, concentrations, and estimating the secondary organicproblematic aerosol (Pio contribution et is al., especially 2011). emissions inventory data are least reliable,problems. wood smoke Collecting stands activity out data as for posing emissions particular inventories is challenging and emission more di 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | over onto 1 1 − − 880 and , min 3 660 , W). It is in the ◦ 590 , 25.4 cm QM-A What- 520 × , size fraction with a pre- N; 0.21 ◦ 5 . 470 2 , 370 . Data were corrected for loading = 1 inlet operating at 0.5 m λ − 5 . 2 W). It shows a large increment in particle ◦ 6810 6809 for 24 hours with a 20.3 W), 55 km to the southeast of Birmingham and 1 ◦ − N; 0.16 min ◦ 3 − N; 1.38 ◦ cked roads. There is little residential accommodation within ffi (Yin et al., 2010). cked (ca. 80 000 vpd) six lane highway running through a street W) is a urban background site located in an open field within inlet and operates at 4 l min 5 . ◦ ffi 2 5 . 2 N; 1.93 ◦ ects according to the commonly used algorithm of Weingartner et al. (2003). For some of the sampling periods, a Magee Scientific multi-wavelength aethalometer ff providing absorption data at950 nm) was seven deployed wavelengths for the ( measurementwas of fitted black and with brown a carbon. PM e The instrument 24 h onto a Whatmanof QM-A potassium 150 mm and diameter calcium quartzmous Partisol were fibre Plus filter. collected model Samples using 2025and for a sequential fine analysis particle air Rupprecht fractions, sampler and and which47 only Patashnik mm collects data polypropylene-backed dichoto- separate for PTFE coarse the filters fine were fraction used sampled in at the 15 study. l min the sampling location. 2.1 Sampling procedures Samples for levoglucosan analysis wereume sampler collected operated with at 0.9 a m man Graseby-Andersen high quartz vol- fibre filterimpactor. substrate At the after London selection Norththe of Digitel Kensington DH-80 sampling the automated site, PM sampler samples with were a collected PM with This is a rural location4 km (52.17 to the westan area of of Warwick). hardwood forest Thedomestic and sampler wood was was stoves subject and located to from local in wood the a smoke open clearing emissions burning on both of from the waste edge wood of about 50 m north of Budbrooke, Warwick Sampling Site Marylebone Road, London This is on a heavily tra canyon in central Londonmass (51.52 above neighbouring centralthe urban particle background sources sites influencing (Charron theal. (2011). site et have al., been 2007) identified and tentatively by Harrison et a station of thecepted National as representative Automatic of air Urban quality andclimate across a at Rural large this part Network. site of London has The and been the site analysed air in pollution is detail widely by ac- Bigi and Harrison (2010). and some moderately tra 300 m. Data fromreceptor model this of site PM have previously been used in aNorth Chemical Kensington, Mass London Balance This is angrounds urban of a background school in site a in residential area, West 7 km London to the (51.52 west of central London and hosts EROS (52.45 the Birmingham University campus.of The Birmingham site which has is aof about population 3.5 2.5 km of million over southwest one of population. million the and centre The is part nearest of anthropogenic a sources conurbation are a nearby railway, Elms Road Observatory Site (EROS), Birmingham 5 5 15 20 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | was used ) 1 soil − Ca] / C min ◦ [K × 1 . 0 ects and variations in the ff − C) to approximately 5–10 ml. (1 ◦ ratios for the ions used in the / ) nss m/z Ca C in a dry heater block. After derivati- × ◦ soil Ca] 6812 6811 / [K C refrigerator until derivatization. C for 4 min , a gradient of 20 ◦ ◦ − ) was applied as recovery standard. The addition of 30 H 18 measured non-sea salt. Na = × and was held for 20 min. The 20 µm size fraction which was extracted with water and analysed C. The carrier gas was helium at a pressure of 120 kPa. The tem- 036 1 ◦ . < − 0 − C min ◦ C, followed by 10 min at this temperature, then the temperature increased to ◦ ) was spiked evenly across the aerosol filter segment (1/4) to account for measured 5 0 (K C at 5 12 ◦ = H Quantification was carried out by GC/MS and was based on an internal standard cal- Aliquots of 50 µl of the sample solutions were taken out and derivatied by trimethylsi- The derivatization process was carried out on batches of 10 samples The spiked filters were extracted three times, each time for 20 min with 30 ml of The concentrations of potassium needed to be corrected for the minor contributions 6 ws immediately by GC/MS. ibration procedure with appropriate recoveryof and 1.0 µl blank was corrections. injectedtemperature A into of sample 250 a volume split/splitlessperature injector, program operated was in started theup at splitless to 45 mode 100 at a 315 GC/MS analysis are 204, 217 and 333. using thetrimethylsilyltrifluoroacetamide (MSTFA) trimethylsilylation andtrimethylsilylation 1 % mixture mixture trimethylchlorosilane was (TMCS). freshlywas which performed The made in before a comprised sealed thezation, vial the derivatization for sealed process 60 99 vials min % were which at opened 80 to add of the recovery standard, N-methyl-N- and then analysed in pyridine (200 µl) then kept in the 4 lylation mixture (40 µl).added in to After the sample derivatization,study, and 1-phenyl total a dodecane of (C 10 100 µl µlrecovery final recovery standard sample was was standard to analysed (1 by compensate ppm)GC/MS GC/MS. for In detector injection was this response. volume e dichloromethane under ultrasonic agitation.acidic conditions The by first addition extraction of acetic wastracts acid were performed (200 reduced µl). under with a The rotary combinedThen evaporator dichloromethane the (400 ex- concentrated hPa, 25 extracts were filtered throughorated a under PTFE a filter and stream completely of evap- nitrogen. Finally, the evaporated samples were re-dissolved losses during sample extraction and concentration. K where the subscript nss Levoglucosan Two procedures were used forand the analysis Budbrooke of sampling levoglucosan.et Samples sites al. from were the (2002). EROS analysedC Before according extraction, to an the internal standard method (methyl-beta-D-xylopyranoside, of Zdrahal according to the samewere methods adopted. as The equation the usedis air to as filters. estimate follows: the Therefore, potassium arising site from specific wood corrections smoke (2008). of sea salt andPio soil et to al. the (2008) finesoil which fraction. use and The sodium assumes corrections as a werethe a based mass corrections, tracer on ratio for the the sea of standard methodsoil salt 10 ratio of and calcium for of calcium concentration K/Ca K/Na for wassieving in of a to tracer wood 0.036 estimated collect of in smoke. a by sea the In salt sampling order was of to adopted local generate and soils the followed by Potassium PTFE filters were extracted intosium, water sodium and analysed and by calcium ion according chromatography for to potas- the methods described by Yin and Harrison 2.2 Chemical analysis 5 5 25 15 20 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , c + Q (1) (2) ffi c at 370 nm ffi cients measured ffi C6 isotopically used c. Linear regression ffi 13 values were “despiked” and , values of aerosol attenuation 2 ATN b value which sum to give the total ) dependent λ (950) were derived from attenuation wb , can be derived. When comparing 67 cm α . 370 nm and 950 nm) measured across erent absorption coe 1 abs ect of the particles as the filter becomes = ff b ff = λ A and PM 6813 6814 c ffi tra (370) and c particles (which have a higher of content of black ¨ om exponent c and wood burning has a fixed value (1.0 and 2.0 was wavelength ( ffi ffi c abs ffi c. It follows that abs b cient for both wood smoke and tra tra ffi b α ffi ˚ wb Angstr − levoglucosan. α  − 1 erent wavelengths (  ff − cients cient ffi ffi 950 370 and the filter spot size  950 370 t c and wood smoke have a stronger absorption at the shorter wave-  = are both beam intensity before and after attenuation by the particle- were calculated using ffi c c  = I 6.1 µg g ffi ffi o I I ± abs tra tra wb wb t  b and ATN ∆ o ∆ I a − A Q ¨ 100ln λ om exponent for both tra cients ≡ = ∝ (950 nm) (370 nm) (950 nm) (370 nm) ffi Given the measured values of ATN for each of the wavelengths, the flow rate The absorption coe The absorption coe The two procedures for levoglucosan analysis were intercompared both using a set Samples from London North Kensington and Marylebone Road were analysed ac- abs abs abs abs ATN abs ˚ b b b b b laden quartz tape filter. the sampling time coe in which For both wavelength (370 andsmoothed 950 nm) using channels, an the in-house algorithm,was before applied a to correction account due forloaded. the to “shadowing” Weingartner e (2003) b calculate an absorption coe then correlates these values toCM values. a PM values ATN of the two di a quartz tape filter. ATN and from this relation,the the ratio of thematerial) absorption to by the the absorption woodcarbon), smoke by both tra (which tra has alengths, higher content but of wood organic smokecompared to absorbs 950 nm. significantly This morewood is smoke radiation reflected compared by than to the tra tra typically higher absorption exponents for and wood burning to theblack total carbon) measured can carbonaceous be material, apportioned CMfor using (organic both the matter di sources atAngstr 370 nm andwere 950 nm used, by respectively), the simultaneous aethalometer. equations By can assuming be that derived – the and solved – to internal standard was utilised. of environmental samples and bycontains analysis 81.1 of levoglucosan in NIST SRM 1649B which Aethalometer Using the methodology of Sandradewi et al. (2008a,b) the contributions from tra cording to theThis method method of uses Yue and10 derivatization % Fraser trimethylchlorosilane with (BSTFA-TCMS) (2004) N, with as subsequentilent O-Bis GCMS described Technologies analysis (trimethylsilyl), GCMS on by (GC-6890N trifluroacetamide an plus Yin Ag- (30 plus MSD-5973N) m, et fitted 0.25 mm al. with diameter, a 0.25 (2010). HP-5MS µm column thickness). A levoglucosan-U 5 5 10 20 15 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | c wb ffi and from 3 cients. wb (370) − ffi abs cients took b (370) ffi abs b . 2 c. However, the weekday di- −   cient values. ffi wb cients gave a diurnal profile of ) is rather surprising, especially erence in levoglucosan/K ratios ffi ff wb wb ffi traf traf wb . In this work, the coe wb (950) (370) from tra (370) (950) c absorption components, x (370 nm) ffi c-related concentrations and a nocturnal abs abs abs abs b b ffi b b 351 591 µg m abs   b = and PM c rush-hour periods which look as if they may 6816 6815 # # × c erent diurnal profile and higher concentrations ffi ffi 2 wb wb ff α α c tra c absorption components are + − + ffi

1 1 c ffi 950 950 370 370 erentiated in Fig. 2 showing the clear seasonal depen- tra ff wb ) traf traf λ α α ( + − 196 438 and c2

1 1 = abs 950 nm erence between the BC values measured at 370 nm and 950 nm b (950 nm) 950 370 950 370 ff + BC abs c − " " ffi b they are regressed against the total daily carbonaceous matter con- = = tra × )   1 λ traf ( c 370 nm , respectively. = abs ) BC traf (370) (950) (370) (950) b 5 (950) . as is normally observed for CO or NO = 2 = abs abs abs abs c ) abs ffi b b b b λ b (950) (   tra During the course of the work, the Delta-C method was proposed by Wang et Combining the above equations gives the following matrix: Having solved for the wood burning and tra abs abs a typical rush hour-related patternelevation in to the the wood tra smoke, with a lesser diurnal variation at weekends when houses Data from this siterather were limited than to sampling two throughcosan/K campaigns appear the in in summer entire Table and 1, year.summer winter and and winter respectively, the Basic data relationship statistics aredence between di and of the concentrations, ratios variables but no of inbetween obvious Fig. seasons. levoglu- systematic 2. The di middle panels The inand Fig. wood 3 smoke show diurnal estimated variations fromIn in this PM the from case, aethalometer tra these data conform using to the expectations default in coe terms of the shape of both profiles, with the concentration reductions during tra be an artefact ofseen the on weekends method. are more The in di line with expectations. 3.2 North Kensington variation with elevateding concentrations is from required October andMarch to to consistently September. February very Basic low whenTable statistics 1 concentrations home and and of ratios heat- the around ofsonal levoglucosan/K relationship 0.01 µg are variation between m summarised in the in ratio variablesthe appears was aethalometer in evident. data Fig. (Fig.PM 2. Calculation 3) of using No wood the clearurnal smoke default sea- pattern coe concentration for estimated from wood burning smoke (PM 3.1 Elms Road Observatory Site (EROS),This Birmingham was the longest campaign,tions lasting of in all levoglucosan for are 11 summarised months. The in measured Fig. concentra- 1. This shows the expected seasonal using the aethalometer and the in-built absorption coe Delta-C 3 Results where each term corresponds tothe PM following values: c1 al. (2011) and datasimply have taken also as the been di analysed according to this method. Delta-C was CM(PM and centrations, CM where the woodb burning and tra b 5 5 20 25 15 10 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | c wb ffi , probably cients (see ws ffi erence between ff cients strongly sug- 85 57 ffi . . 0 0 c emissions of 0.3–0.4 = = ffi coe 2 2 2 r r r c particles was estimated and ffi ) ratios ws 97 . 0 3 − 3 = − 2 r c contribution. A summary of the measured ffi 6818 6817 05); . 0 002 µg m . 015 µg m ± . 0 0 − 03( − . 0 − erence for N. Kensington in the median, but not the mean ff 87NK 141NK . . 0 1 = = 03)BC . 0 ± MR ratio than winter emissions from wood burning stoves. However, this 57( ws . cient for levoglucosan than potassium is not readily explained, but may 1 mass concentration. ffi = c ffi c coe ffi tra 2 r tra 5 ws . 2 The analysis of aethalometer data for this site using the default coe These gradients of close to one and moderate to high In the case of the N. Kensington data, a mass of tra is an area of Londonbe with infrequent. high density Greater housing degradation where of garden levoglucosan bonfires in are summer expected than to winter (Hennigan 4.1 Levoglucosan: Potassium (levoglucosan/K The range of levoglucosan/K ratios (10–90thconsiderable. percentile) Negative shown values for arise all from sites occasionallyassociated in negative with values Table advection 1 of of is K soils withcorrection. a The low seasonal K/Ca di ratio, thereforeis causing in an excessive the expectedlevoglucosan/K direction, with summer garden bonfires expected to have a higher Fig. 3) showed profiles ratherthan similar PM to North Kensington, but with much higher PM 4 Discussion a wide ratio ofAnother levoglucosan/K consequence ratios of was the expected,cosan mixed and sources and was was K observed that seen (see thelevoglucosan/K in Table correlation ratio 1). Fig. between showed 2 levoglu- a was strongWe much interpret seasonality weaker this (Fig. than as for 4) reflecting thein not a other the seen greater sites. contribution at warmer to the At months, woodemissions. other this smoke with sites. from site the open the low burning ratio in January dominated by the home heating This campaign ran from Novemberson 2009 most to April impacted 2010 byinfluences and wood both therefore included of smoke. the local sea- from and As forestry regional outlined activities. sources above, The of the latter wood involved site smoke burning was from of home subject wood heating in to the and the open air, and hence 3.4 Budbrooke, Warwick mercial buildings, rather thanconcentrations. domestic, and this has the slightly higher levoglucosan for levoglucosan MR (Note: The subscript “ws”studies has from been those derived used from to the distinguish aethalometer, the designated results “wb”.) gest of a chemical rather tracer uniform distributionlower of wood smoke markersreflect across greater central localised London. emissions of The to the explain former as than the the Marylebone latter Road marker, site but is this surrounded is largely hard by institutional and com- data appears in Table 1, showingRoad concentrations to of be levoglucosan and very Kbetween similar at the in Marylebone sites magnitude gave to the following those relationships: atfor North K Kensington. Regression plots estimated by Harrison andratio Yin of (2008) and around Pio 1.5,particle et mass. which al. is (2011), high together with suggesting an a3.3 OM:OC modest over-estimation of Marylebone the Road, London tra Air samples were collected overNorth the same Kensington. one The month period sitesthe as are two the separated has winter by often campaign about been at 4 used km to and infer the a di tra regressed upon the mass of black carbonPM (BC). This showed a very close relationship. The gradient is consistent with a primary OC:EC ratio in tra may be occupied throughout the entire day. 5 5 25 20 15 10 25 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 1 ∼ − are 5 . 2 ratios, these ws N. Kensington > in between, with no in a forest fire (Pio et 5 ratios in summer. Tak- . ratio. Levoglucosan as a 2 ws ws EROS quercus > . Ranges reported for PM 10 and relationships appear plausible: pinus ws with or under-estimation of levoglucosan as might 6820 6819 relationships revealed by Fig. 2 is not suggestive ws ws eucalyptus in a US fireplace (Schauer et al., 2001) to 50 for spruce in ratio is highly sensitive to combustion conditions with high ws quercus to 4.9 for ratios is clearly out of line with earlier studies, and requires explana- . While these are not independent of one another, there still appears 1 ws − 20 % carbonaceous content. Particulate emissions from the other four de- acacia < ates (Kelz et al., 2010)sodium in present which (T. potassium Brunner, personal dominated communication, withreported 2011). only that minor Boman alkali amounts et metals al. of dominate (2004) the mass of inorganic particulate matter from temperature flaming combustion leadingganic to carbon a content and more hence complete aproportion burn-out low of levoglucosan/K of wood the smoke or- (Puxbaum particles et is reported al.,Rasmussen to (2003), 2007) range the from in102 abundance 43 mg g published to of 309 K studies, mg g to in while be wood much according smoke scopeported can to for in range levoglucosan/K the Khalil ratios literature. fromfrom well Kelz and 1.6– modern et outside al. state-of-the-art the (2010) and range comparedvices older particulate of included combustion matter those appliances. a emissions re- Theand pellet modern tiled boiler, de- stove, wood and chipstove. the boiler, older The devices logwood particulate comprised boiler,inorganic, a while matter logwood the logwood from stove modern boiler the woodchipwith and boiler modern logwood and logwood pellet boiler boiler emittedvices particles was were predominantly almost carbonaceous 100 with % organic ca. compounds. 60–90 % The elementalcarbon emissions carbon and from content the contained three 70–90 % modern alkali devices with metal lowest sulphates, chlorides or carbon- the levoglucosan/K Three explanations for low levoglucosan/K Schmidl et al. (2008) measured a range of organic compounds and metals in emis- The ranking of levoglucosan/K ratios of Budbrooke There appears to be a huge variation in levoglucosan/K ratio according to the wood 1. in winter as might be anticipated (Fig. 1), and relate inversely to temperature (Fig. 5). ture of the activitieslevoglucosan/K local to the threetion. sites. The form of However, the the levoglucosan/K of absolute any systematic magnitude over-estimation of ofbe the K reflected in a large intercept. The concentrations range from low in summer to high combustion in open air sources leads to high levoglucosan/K ratios, given the na- Marylebone Road is in the order anticipated if the contribution from smouldering sions from an old type ofratios domestic tiled ranged stove (from from 1994). 19.5 Thecommented reported to that levoglucosan/K the 216 abundance forthan of the in ionic various species many wood (including previousthe types. studies K) burn. in due However, This their to these is work samplesbiased likely authors was being to the lower taken have levoglucosan at not data only theconsidering biased the start upwards the entire and leading K combustion. middle to data of downwards, unreliable it levoglucosan/K will ratios also have if type. According to datastudies reported in by an Goncalves Austrian-design et woodas al. stove, 0.19 (2010) levoglucosan/K for derived ratios from cansystematic combustion vary variation from between as hardwoods and low softwoods. an Austrian wood stove (Schmidl, 2005),narrower, from both 33.3 for PM for softwood inwood a in US a woodstove US (Fine fireplace etof (Fine al., ratios et 2004) from al., to 6.25, 2001). the foral., Caseiro recent soft- 2008) et literature, to al. 200 ranging (2009) from from alsoal. softwood provided 0.11 (2007) burned a report for in review chemical a PM profiles woodstoveoglucosan/K (Schmidl of ratios et hardwood are al., and 0.77 2008). softwoodspanning combustion and Chow in the et 0.15 which values for lev- measured hardwood in and this softwood, study. respectively, nicely ing the gradients of Fig.were 2 respectively as 0.74, the 0.34, bestand 0.18 representation of and N. levoglucosan/K 0.15 Kensington for respectivelyal. Budbrooke, (2007) and EROS, from fall Marylebone published studies. Road wellfrom The outside ratios reported of the data 1.1 from range for Puxbaum cited et al. by (2007) Puxbaum range et et al., 2010) would be expected to reduce levoglucosan/K 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | - ff ws ws 25) 5.9. . 0 = = 0.63) in 2 r = 2 r erent. Levoglu- ff . Figure 6 shows ws erence in estimated ff 25). Wang et al. (2011) . 0 may be di = 2 r ws erences between levoglucosan and K will ff cient combustion and lower levoglucosan/K ffi fraction, it seems likely that the atmospheric 6822 6821 5 . 2 ce buildings, etc. 2) and at North Kensington (winter) the two variables . ffi 0 = 2 ering a more e r ff erential lifetimes relative to deposition. It is likely that levoglucosan and K plot was 4.0 ( ff ws erence between the seasons, except at Budbrooke, where summer ratios are ff cient for black carbon at both wavelengths and taking the di There is an unrecognisedlarger source in of winter than K.sibility summer To cannot and be be to significant, entirely correlate excluded, this with the would levoglucosan. probability need is While thought to this to pos- be be low. be a minor influence upon the airborne ratios. The atmospheric lifetimes ofcosan has levoglucosan a and potential K man for et atmospheric al., degradation 2010), (Hennigan whereasto et K reaction does al., with not. 2010; a The Ho as typical lifetime 0.7-2.2 of days summer levoglucosan (Hennigan concentration with etlower of respect al., than hydroxyl those 2010). in radical As summer, is such winterThis degradation concentrations estimated will alone of be therefore hydroxyl appreciably seems are slower in unlikelyeven winter. if to the influence majority the of levoglucosan/Kdecomposition wood ratio of smoke greatly, levoglucosan is would advected lead fromter to distant higher than sources. levoglucosan/K Appreciable summer, ratios for indi which win- Table 1 giveshigher no for clear reasons support, explained withfrom earlier di little in systematic this paper.co-exist in Another the same possible particles, influenceparticle but is size. with No a range informationas of is the ratios available which on sampling may the waslifetime depend respective of will upon size-associations, be the but several PM days and any di the combustion of pelletised biomass fuels.to Potassium be and chlorine the were dominant reported elements.open There fireplaces is and a wood lackburning burning of stoves stoves information most in on in the UK use. relativethe homes, use use However, or of there of on wood has as the been athe types a domestic prices of fuel considerable of in natural increase wood recent gas in years, andof accompanying electricity. modern the There rapid designs may, therefore, rise o be in aratios. preponderance There has alsosystems for been schools a and significant o uptake of larger wood-burning heating ffi 3. 2. it needs to beis borne not a in direct mindDelta-C/K measurement that of Delta-C wood smoke is mass.were a uncorrelated. At surrogate Budbrooke, for Wang the woodtheir et gradient smoke al. winter of mass (2011) the dataset, and found andratio a measured lower at Delta-C/K Budbrooke. values slope The in ofseen generally low spring in 6.2 correlations our and ( between data, Delta-C fall, and andcorrelations K broadly the is suggestive fact consistent of that with an these interference the fall (possibly below by the SOA) values in of the the Delta-C levoglucosan-K method. and at the Northalso Kensington showed site a (winter relationship data) to wassoil. potassium 6.5 although ( Our this was data not forthe corrected both black for sites sea carbon salt showed measurements or values a at of very the Delta-C poor two in relationship wavelengthsurnal the to profiles together Budbrooke K in with and Delta-C the North with the calculated Kensington strong winter evening datasets. maximum look These extremely plausible di- but Wang et al. (2011) have recentlyand shown that 880 nm the enhanced in absorptionwith between the 370 wood nm two smoke wavelength markers,culate aethalometer although wood (referred they smoke masses. to docoe not as Delta-C propose Delta-C) is a calculated correlates black factor using carbon the with concentration. conventional which The absorption to gradientter observed data cal- (giving by Wang the et greatestIn al. range our of (2011) data, concentrations) in was their the Delta-C/levoglucosan win- ratio Delta-C/levoglucosan at the Budbrooke site was 4.5 ( 4.2 Comparison with Delta-C method 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | at 5 . 2 3 − ecting sites ff and biomass /levoglucosan cult to propose ws ffi ws 3 cient larger biomass − and levoglucosan, we ffi erent K ff ws used in non-domestic boilers 3 − 1 − concentrations and the mass of ws 6824 6823 35 cult to estimate the airborne wood smoke con- . to make up around 50 % of the mass of such 7 ffi × ws levoglucosan is far smaller than the 322 PJ yr = 1 − is considerably less close at our sites than was reported by Caseiro et ws According to the studies reviewed by Puxbaum et al. (2007), OC represents between Puxbaum et al. (2007), based on a review of literature data available at the time, A survey of consumption of solid fuel in the UK and Ireland (Ecosolidfuel, 2008) has al. (2010), itaerosol is which quite would feasible imply for an K additional contribution of biomass burning to PM Budbrooke, Warwickshire (November 2009–April 2010) 0.42 µg m The literaturesmoke is mass. far However, given thethink less very it likely high clear that ratios there betweenburning on is installations K a generating the separate emissions with sourcehave a category relationships very of little low highly between organic influence e content upon which K would airborne levoglucosan. Judging from the work of Kelz et derived: Birmingham, EROS (May 2009–March 2010) 0.23 µg m London, North Kensington (June 2010 and February/March 2011) 0.33 µg m Biomass smoke OC 51.3 and 100 %wood of stoves PM presented from by biomasssmoke Puxbaum mass combustion. et and al. levoglucosan Using can (2007),give the be the a derived data relationship range and for the between of fireplacesapplied various biomass 4.51 to and studies to reviewed the there 24.6 measured with levoglucosan data, a the mean following value average of concentrations 11.2. are If this value is adopted and by the modern devices tests bya Kelz et specific al. factor (2010). between Consequently, itwood either is smoke di levoglucosan particles. or K propose use of the relationship: domestic boilers having a much lower levoglucosan to potassium ratio as exemplified relative to potassium. On the other hand more advanced domestic boilers and non- suggested the following split:stove 0.1 %; open domestic fireplaceof boiler 11.5 %; around 66.3 %. 75 closed PJ yr fireplacewith However, outputs 22.1 the of %; energy up pallet to consumption aroundlatter 500 in are KW this more (R. Stewart, form likelyrequire personal to communication, combustion be 2011). of The used solid inrequirements. fuels cities, It consequently in where seems in devices likelysuch the demonstrated that as the UK to EROS UK smoke meet urban and control emissions specificopen London a regulations fireplaces emission North and Kensington closed devices comprise which a are mixture likely to of be wood relatively burning rich in in levoglucosan rise to the questionsured as data. to At whether Budbrooke, more thisand than open is one burning clearly source of the wood type caserelationships. which is with However, would the influences influencing be situation both the expected is of mea- to less wood give clear stoves di for the other sites. Our levoglucosan/K ratios are entirelywe out think of it line inappropriate withcosan to Schmidl and use et K these al. data (2008)al. and directly. (2009) hence The from relationship measurements between inreported levoglu- Vienna, by Graz Saarikoski and et Salzburg.sium al. It in (2008) four is central also between and lower northern monosaccharideDelta-C than European anhydrides cities. and that and Additionally, levoglucosan the potas- is relationship weaker between the than fact that that observed their data by were Wang not et corrected al. for (2011) potassium despite from other sources. This gives From single marker data,centrations. it is The very factor di ofto 10.7 Austrian between conditions levoglucosan reported and byas wood Schmidl indicated smoke et mass above, al. relating this (2008) may has be been widely an adopted, over-estimate but for the entire combustion process. 4.3 Estimation of wood smoke concentrations 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 3 − as 5 . 2 3 − of biomass 3 − 3 , almost four times the mean cult due to the lack of a flue − 3 ffi − of biomass smoke, although very 3 ratios as follows: − 0.3 in biomass smoke which implies ws = . If this is assumed to be 20 % of biomass 3 in winter. In the light of our current data, the − 6826 6825 3 − (winter campaign) which are far closer to the cur- and very much lower than some other estimates 3 3 − − cient installations, then the two sets of concentrations ffi culty of achieving an accurate split between elemental and ffi of wood smoke, which would cause a marked seasonal variation in 3 − in summer and 0.08 µg m 3 − samples were collected between June to September 2007 and January to May which is not observed. 5 cient small appliances such as wood stoves and fireplaces, and on the other hand . 10 2 ffi The only other UK data of which we are aware are from Fuller et al. (2011) who re- Further indirect evidence is available from the study of Heal et al. (2011) in which Birmingham, EROS (May 2009–March 2010)London, 0.08 North µg m Kensington (June 2010If and there February/March are 2011) two 0.30 distinct µg m source types, i.e. on the one hand wood burning in relatively C was measured in aerosol collected at the EROS site in 2007/08. In all, some 75 wood in domestic premises islevoglucosan concentrations largely correlate limited so to strongly rural between areas the of Marylebone the Road UK and and the fact that are very low atfor well the below UK (Fuller 1 µg et m those al., measured 2011). elsewhere It in is Europethere recognised (e.g. may Puxbaum that be et these good al., concentrations reasons 2007, arehave for Bari far fireplaces this. et below and al., Most the 2010) modern but and fitting urban chimney. dwellings of Most in wood UK the stoves urban UKthe is areas no use are very longer of subject di many to kindslessly. smoke of There control solid are fuel orders very other which limited than prohibit suppliesareas in of for devices logs designed purchase and to wood by burn products domestic them available consumers within smoke- urban for combustion. Consequently, burning of 5 Conclusions This work is suggesting that annual mean concentrations of biomass smoke at UK sites uncertain due to theorganic carbon di in thesmoke, samples is not and strongly the out ofanalysis uncertainty line above. surrounding with the the estimate %EC for EROS in derived biomass from levoglucosan ported mean winter levoglucosan inconcentrations London of measured 176 in ng m our studyto in about winter 3 at µg m NorthPM Kensington. They equate this total carbon equating tosmoke around (Schmidl 0.1 et µg m al., 2008),smoke. this The equates figure to of EC a being concentrationMinguillon 20 et of % of al. 0.5 biomass µg (2011) m smoke assume is aan highly ratio EC uncertain of content – of EC/OC for below example 14 %. The value of 0.5 µg m of the days selected. The average contemporary elemental carbon was only 2 % of CMB method have shown(summer higher campaign) and concentrations 0.36 µg at m rent North dataset. Kensington of 0.23 µg m 14 PM 2008 and a subset of 26contemporary samples elemental were carbon analysed is for their interpreted “fraction asthis modern arising again carbon”. from showed The rather biomass little combustion and seasonal variation which could once again be an artefact lack of an obvioussampling seasonal for only variation five is daysit surprising of is each but possible month the that asoverall sampling opposed the period to regime of concentrations daily sampling. involved measured in Nonetheless, wereterms the the not of current two the datasets work wholly are magnitude and representative not of of strongly concentration. out the More of recent line unpublished in data also using the should be approximately additive for a given location. 4.4 Comparison with earlier UK data There are two sets ofvant to earlier intercompare. data Yin for et thecalculated al. Birmingham, source (2010), EROS contribution using site estimates a with for Chemical0.07 which Mass wood µg m it Balance smoke is (CMB) as rele- model, a contributor to PM ine combustion in larger more e the urban locations with very low levoglucosan/K 5 5 20 25 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 10 doi:10.5194/acp- cked London site?, ffi cient to cause a sig- ecting concentrations of ffi ff , in Proceedings, European 10 c emissions were expected to ffi ) at a heavily tra 3 − ecting carbonaceous aerosol in central ff emissions from woodstove combustion of knecht, G.: Temporal variation and impact ff 10 6828 6827 concentrations such as would lead to a distinct 10 limit value (50 µg m , last access: 15 February 2012, 2008. 10 or PM ) in the UK atmosphere, Atmos. Environ., Atmos. Environ., 46, 5 5 . . 2 2 The authors acknowledge financial support from Defra under contract , 2007. www.ecosolidfuel.org common woods grown in Portugal, Atmos. Environ., 44, 4474–4480,England, 2010. Atmos. Environ., 42, 1413–1423, 2008. spectra collected on a major highway, Environ. Sci. Technol., 45,fine 5522–5528, particulate 2011. matter (PM Aerosol Conference, Manchester, September 2011. H., and Carvalho, F.: Characterisation of PM and Magliano, K. L.:portionment Evaluation at of the Fresno organic Supersite, markers Atmos. for Chem. chemical Phys., mass 7, 1741–1754, balance source ap- from the wood stove combustion21, of 705–721, prevalent 2004. United States tree species, Environ. Eng. Sci., Kelly, K. J.: Contribution of biomass burning to London’s PM for exceedences of the 24Atmos. h Environ., PM 41, 1960–1975, 2007. 7-1741-2007 from fireplace combustion ofTechnol., woods 35, grown 2665–2675, 2001. in the northeastern United States, Environ. Sci. in three Austrian regions, Atmos. Environ., 43, 2186–2195, 2009. matter from residential combustion2004. of pelletized biomass fuels, Energ. Fuel., 18, 338–348, site, Atmos. Environ., 44, 2004–2012, 2010. The multi-wavelength aethalometer calculations suggest higher concentrations but of wood smoke pollution3823–3832, on 2010. a residential area in southern Germany, Atmos. Environ., 44, Harrison, R. M., Laxen, D., Moorcroft, S., and Laxen, K.: Processes a Harrison, R. M. and Yin, J.: Sources andHarrison, processes R. a M., Beddows, D. C. S., and Dall’Osto M.: PMF analysis of wide-range particle size Goncalves, C., Alves, C., Evtyugina, M., Mirante, F., Pio, C., Caseiro, A., Schmidl, C., Bauer, Fuller, G. W., Tremper, A.H., Baker, T. D., Yritt, K. E., Butterfield, D., Mudway, I. S., Dove, R., and Fine, P., Cass, G., and Simoneit, B. R. T.: Chemical characterization of fine particle emissions Chow, J. C., Watson, J. G., Lowenthal, D. H., Chen, L. W. A., Zielinska, B., Mazzoleni, L. R., Charron, A., Harrison, R.M. and Quincey, P.: What are the sources and conditions responsible Ecosolidfuel: Fine, P., Cass, G., and Simoneit, B. R. T.: Chemical characterization of fine particle emissions Caseiro, A., Bauer, H., Schmidl, C., Pio, C. A. and Puxbaum, H.: Wood burning impact on PM Boman, C., Nordin, A., Bostrom, D. and Ohman, M.: Characterization of inroganic particulate Bigi A. and Harrison R. M.: Analysis of the air pollution climate at a central urban background Acknowledgements. et al. (2011) in thedata United and States ignore suggests that theof we more the can extreme place method concentration trust ofcollected estimates in Sandradewi in the deriving a et levoglucosan from Swiss al. Valley application be where (2008a,b) the wood which only smoke significant was and sources based tra of originally absorbing aerosol. upon data tention that wood smoke concentrations in London and Birminghamwe are relatively discount low. these onthe the fact basis of that their theto inconsistency interference aethalometer with from method the HULIS (humic-like levoglucosan whenSince substances) data this applied within interference and to is secondary variable, organic UK theremay aerosol. is locations strongly no will correction over-estimate for beDelta-C it concentrations. subject and and therefore levoglucosan the The method in fact our that measurements the is similar relationship to between that obtained by Wang AQ0707 and from thetre for Natural Atmospheric Environment Science. Research Council for funding the National Cen- References Bari, Md. A., Baumbach, G., Kuch, B., and Sche the datasets from Birmingham,seasonal EROS variation, and the London, estimated North woodnificant Kensington smoke show perturbation masses a in are marked PM insu seasonal pattern. Such aBigi pattern and is Harrison not (2010) observed for at London, UK urban North sites Kensington), (see further for supporting example the con- North Kensington sites may imply an advected rural source of wood smoke. While 5 5 30 25 20 15 10 15 10 25 20 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ˜ nano, ˜ nuelas, at road- 10 in the UK, Atmos. and PM cient by means of 5 . 5 ffi . 2 2 ¨ , PM a, K., Seco, R., Pe , 2011. 0 . 1 ects, in 18th European Niomass ff c aerosols in an Alpine valley using a ffi c emission contributions to particulate matter, ffi 6830 6829 organic compounds from fireplace combustion of wood, ¨ uller, M., Hansel, A., Burkhart, J. F., Baltensperger, U., 29 doi:10.5194/acp-11-12067-2011 –C 1 ¨ , H., Schnaiter, M., Streit, N., Bitnar, B., and Baltensperger, U.: Ab- a, M. K., Saarnio, K. M., Hillamo, R. E., Pennanen, A. S. and Salonen, ¨ ff a ˆ ot, A. S. H., Weingartner, E., Schmidhauser, R., Gysel, M., and Bal- ˆ ot, A. S. H., Szidat, S., Perron, N., Rami Alfarra, M., Lanz, V. A., Weingart- – Quellenprofile von Holzrauchemissionen aus Kleinfeuerungen diploma ´ ev er, A., Decesari, S., Moretti, F., Hillamo, R., Teinil ´ ev ff 10 C analyses to source apportionment of carbonaceous PM 14 ˆ ot, A. S. H.: Fossil versus contemporary sources of fine elemental and organic ´ ev ´ on, M. C., Perron, N., Querol, X., Szidat, S., Fahrni, S. M., Alastuey, A., Jimenez, J. L., man, D., Tilgner, A., Ilnuma, Y., and Herrmann, H.: Atmospheric stability of levoglucosan: ff side, urban background and rural sites, Atmos. Environ., 42,particles 980–988, 2008. at urban background841–851, 2010. and rural sites in the UKTexAZS atmosphere, 2000, Atmos. Atmos. Environ., Environ., 38, 3253–3261, 44, 2004. sorption of light byaethalometers, soot J. Aerosol particles: Sci., 34, determination 1445–1463, of 2003. the absorption coe of residential wood combustionSci. Technol., particles 45, using 7387–7393, 2011. the two-wavelength aethalometer, Environ. thesis, Vienna Univ. of Technol., Vienna, Austria, 2005. and Puxbaum, H.:combustion Chemical of characterisation common woods of43, 126–141, growing fine 2008. in particle mid-European emissions Alpine from regions, wood Atmos. stove Environ., ner, E. and Baltenspergertative U.: determination Using of aerosol wood burning lightEnviron. and Sci. absorption Technol., tra measurements 42, 3316–3323, for 2008b. the quanti- from air pollution sources. 3.Environ. C Sci. Techol., 35, 1716–1728, 2001. Legrand, M., Preunkert, S.for and assessing Pio, C.: the Levoglucosan impactGeophys. levels Res., of at 112, biomass background D23S05, sites combustion doi:10.1029/2006JD008114, in 2007. on Europe the European aerosol background, J. tensperger, U.: Amulti-wavelength Study aethalometer, Atmos. of Environ., 42, wood 101–112, burning 2008a. and tra and Pr carbonaceous particulate matter duringChem. Phys., the 11, DAURE 12067-12084, campaign in Northeast Spain,B., Atmos. Sanchez de la Campa,Re-thinking A., the Artinano, Approach B., for Matos Apportionment M.:bon, between OC/EC Atmos. Primary Ratio Environ., Observations 45, and in 6121–6132, Secondary Europe: 2011. Organic Car- Sanchez-Ochoa, A. and Gelencsering A.: the Chemical 2003 composition summer of intense forest atmospheric fire aerosols period, dur- Atmos. Environ., 42, 7530–7543, 2008. R. O.: Impact of biomassEurope, combustion Water Air on Soil urban Pollut., fine 191, partiuclte 265–277, matter 2008. in central and northern 1222, 2003. Mohr, C., Ortega, A. M.,F., Kiss, Day, G., D. A., Ho Lanz,J., V. A., Metzger, Wacker, L., A., Reche, Schallhart, C., Cusack, S., M., M Amato, A detailed laboratory and modeling study, Environ. Sci. Technol., 44,modern 694–699, biomass 2010. combustion systemsConference, 1231–1243, and edited their by: health2010, ETA-Florence e 2010. Renewable Energies, Lyon, France, May biomass burning particles exposeddoi:10.1029/2010GL043088, to 2010. hydroxyl radicals, Geophys. Res. Letts, 37, L09806, 115–124, 2012. plication of Environ., 45, 2341–2348, 2011. Yin, J., Harrison, R. M., Chen, Q., Rutter, A., and Schauer, J. J.:Yue, Source Z. apportionment and of Fraser, M. fine P.: Polar organic compounds measured in fine particulate matter during Yin, J. and Harrison, R. 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L.: Levoglucosan stability in Heal, M. R., Naysmith, P., Cook, G. T., Xu, S., Raventos Duran, T., and Harrison, R. M.: Ap- 5 5 30 25 20 15 10 30 20 25 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ws ws 2.115/2.26 0.477 0.281 0.534/1.074 0.295 0.331 0.459/2.346 0.168 0.656 − − − Levoglucosan/K ) and levoglucosan/K 3 − ws ) data (µg m ws 0.011/0.1770.018/0.037 0.074 0.007 0.075 0.002 0.001/0.165 0.076 0.053 − − − 6832 6831 10th percentile/90th percentile Mean Median 10th percentile/90th percentile Mean Median 10th percentile/90th percentile Mean Median SummerSummerSummer 0.005/0.02 0.010 0.007/0.023 0.009 0.014 0.012 0.007/0.029 0.016 0.013 0.02/0.092 0.049 0.045 0.017/0.057 0.037 0.035 0.146/0.517 0.307 0.316 0.326/0.723 0.495 0.427 Summary of levoglucosan and potassium (K quantifying levoglucosan and relatedand monosaccharide application anhydrides to in747–753, atmospheric samples 2002. aerosols from urban and tropical locations, Environ. Sci. Technol., 36, Marylebone Rd WinterBudbrooke Winter 0.024/0.085 0.050 0.046 0.012/0.14 0.059 0.039 0.039/0.362 0.204 0.221 0.141/1.202 1.349 0.249 SiteEROSNorth Season* Ken. Winter Winter Levoglucosan 0.008/0.058 0.031 0.022/0.069 0.045 0.026 0.044 0.073/0.444 0.251 0.236 K 0.111/0.455 0.356 0.165 Summer: April to October * Winter: November to March Table 1. ratios. Zdrahal, Z., Oliveira, J., Vermeylen, R., Claeys, M., and Maenhaut, W.: Improved method for 5 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

= 0.32 2 r = 0.68 = 2 r

) 003 0. ± ( X + 0.013X + (±0.008) measured at EROS (04/05/2009–

X + 0.007X +

) ws 01 0. (±0.03) ± ( Y = 0.18 = Y

Y = 0.15

6834 6833

= 0.27 = 2 = 0.44 = r 2 r

2) 00 0. ± ( X 0.002+ (±0.007)

X + 0.009X +

) 02 0. ± (±0.06) (

Y = 0.74 Y = 0.34 -a λ ∝ Relationship between levoglucosan and K Monthly variation of levoglucosan measured at EROS between 23/06/2008 and abs 29: Corrected Figure 1, page Proof Corrections: acp-2012-37 acp-2012-37 Corrections: Proof 12, equation (2): Page 10, line b 31/03/2010) (top left plot) andKensington Budbrooke (19/11/2009–08/04/2010) (filled (bottom left circles plot) representsent and North winter) summer (16/02/2011–15/03/2011) (03/06/2010–29/06/2010) and15/03/2011) (top (bottom open right right circles plot). plot) repre- All and are fitted Marylebone using a Road RMA (16/02/2011– regression. Fig. 2. Fig. 1. 31/03/2010. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

6836 6835 at Budbrooke according to month of observation.

ws

Diurnal variation of PMwb and PMtraf measured at EROS (04/05/2009–31/03/2010) Ratio of levoglucosan: K

Fig. 4. Fig. 3. (left panel)(20/11/2009–08/04/2010) , (right panel). North (Topweekends; panel Kensington middle plot: panel (16/02/2011–15/03/2011) average plot: day average including (middle week day; both bottom week panel) panel and plot: and average week Budbrooke end day) Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

6838 6837 Average diurnal variation in black carbon estimated at 370 and 880 nm with the

Variation of levoglucosan with temperature at EROS site.

Fig. 6. aethalometer and Delta-Cpanel). at Left Budbrooke plot: weekday; (top right plot: panel) weekend. and North Kensington, winter (bottom Fig. 5.