STATE OF CALIFO,RNIA
AIR RESOURCES BOARD
SULFATE CONCENTRATIONS IN THE SOUTH COAST AIR BASIN
TD · JANUARY 197& 885.5 S83 KB COPY
CALIFORNIA AIR RESOURCES BOARD Division of Technical Services
SULFATE CONCENTRATIONS IN THE SOUTH COAST AIR BASIN
(DTS-76-1)
By Dona1d Kurosaka Junior Civil Engineer Under the Supervision of: Jack Paskind, Senior Air Sanitation Engineer
SUMMARY AND CONCLUSIONS
Ambient sulfate concentrations have been measured in the South Coast Air Basin for almost 20 years by the National Air Surveillance Network and for ten years by some of the local air pollution control districts. The Metropolitan Zone of the Southern California Air Pollution Control District, formerly known as the Los Angeles County Air Pollution Control District, has conducted the most consistent monitoring in the Basin. · Since 1965, the annual average sulfate concentrations in Los Angeles County peaked in 1972 and have since declined slightly. In 1975, the most recent year for which monitoring data are available, the highest annual average con centration, 12.4 micrograms per cubic meter (µg/m3), was measured at ~ennox, and the highest monthly and 24-hour average concentrations, 21.0 pg/m and 36.3 µg/m, respectively, were measured at Lennox and Los Angeles. Based on upwind-downwind monitoring near freeways, there is some evidence that the catalytic converters on 1975 and subsequent year model automobiles are currently causing a small increase in sulfate concentrations near freeways. However, as more cars become equipped with these devices during the next few years, the expected increase may be noted. Several collection and analytical methods for the determination of sulfates are being used at the present time. It is recommended that a standard method be adopted for universal use by all of the agencies involved in sulfate measurements.
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SULFATE CONCENTRATIONS IN THE SOUTH COAST AIR BASIN Page
Summary and Conclusions i
I. Introduction ...... 1
I I. Air Monitoring Programs A. Routine Air Monitoring of Sulfates 1 1. Los Angeles Zone ...... 2 2. San Bernardino Zone ...... 3 3. Riverside Zone ...... 3 4. National Air Surveillance Network...... 3 5. CoIT111unity Health and Environmental Surveillance System . . . 4 B. Aerosol Studies ... 4 1. Aerosol Characterization Experiment •. 4 2. Air Resources Board Monitoring Program 6 3. Regional Monitoring of Smog Aerosols 6 C. Freeway Studies ...... •. 7 1. Freeway Aerosol Study...... 7 2. Sulfur Dioxide Conversion Study..•.... 8 3. Impact of Motor Vehicle Exhaust Catalysts on Air Quality...... 9 4. Los Angeles Catalyst Study .....• 10 5. Air Resources Board Freeway Monitoring Study 11 III. Sulfate Concentration Data A. Background Levels. 15 B. Ambient Levels .. 15 1. Annual and Monthly Average Concentrations. 15 2. 24-Ho~r Concentrations •...... 16 3. Two-hour Concentrations .•.... 16 IV. Comparisons of Ambient Sulfate Concentration Data A. Yearly Average Comparison. 29 1. Los Angeles Zone-NASN 29 B. Monthly Average Comparisons. . 29 1. NASN - CHESS ...... 29 2. Los Angeles Zone - CHESS - LACS 29 C. 24-Hour Average Comparison. 30 1. Los Angeles Zone - NASN. 30 Page V. Characteristics of Sulfates in the Atmosphere A. Total Aerosol Breakdown and Light Scattering Contribution ...... •.. 37 B. Particle Size and Size Distribution. 37 C. Diurnal Variation. 38
D. Seasonal Variation 38
E. Trend of Ambient Sulfate Concentrations. 38 F. Relationship Between Concentrations for Different Averaging Times. • • ...... • 39 VJ. Relationship of Sulfur Dioxide and Sulfate Concentrations A. Effect of Sulfur Dioxide Emissions 53
B. Conversion Rates •..• 53
C. Ambient Sulfur Dioxide and Sulfate Concentrations. 53 VII. Review of Measurement Techniques A. Methods for Sulfates .•. 58 B. Methods for Sulfuric Acid 62 VIII. References .••.... 65 I. INTRODUCTION Sulfates are not a new addition to the atmosphere but are of growing concern because of their effects on health and visibility, and because the concentrations of this pollutant in air are expected to increase as increasing quantities of sulfur-bearing oil are burned in the Basin. The major source of sulfates in the atmosphere is the combustion of fuels that contain sulfur. During combustion, sulfur in the fuel is oxidized to sulfur dioxide (S02) which is emitted into the atmosphere and gradually converted to sulfur trioxide (S03), and subsequently, sulfate compounds. These compounds, which exist in the air as solid particles or liquid droplets (collectively termed aerosol or particulate matter), include: sulfuric acid, ammonium sulfate, zinc sulfate, zinc ammonium sulfate, ammonfum actd sulfate, .magnestum sulfate, manganese sulfate, iron sulfate, sodium sulfate and 1ead sulfate. · The catalytic converters on 1975 and newer model year motor vehicles promote the conversion of the sulfur dioxide in exhaust gases to sulfates, giving rise to the concern that these emissions of sulfates will increase ambient concentrations near freeways and heavily used streets. To determine the probable sulfate contributions by these vehicles, special studies are _being conducted near freeways in the South Coast Air Basin. The projected shortage of natural gas for the South Coast Air Basin is cause for even greater concern over future sulfate levels. Fuel oil con taining as much as 0.5 percent sulfur may replace natural gas as an industrial fuel, with a consequent increase in sulfur dioxide emissions and sulfate concentrations in the atmosphere. This report summarizes the findings of programs and studies which deal with the monitoring of ambient sulfate concentrations in the South Coast Air Basin. II. AIR MONITORING PROGRAMS In July of 1975, the Los Angeles, Orange, Riverside, and San Bernardino County Air Pollution Control Districts were unified as the Southern California Air Pollution Control District (SCAPCD) and each county was specified as a Zone of the SCAPCD. Then, in December of. 1975, the SCAPCD redesignated the Zones. The Los Angeles and Orange Zones were renamed the Metropolitan and Southern Zones, respectively; and the eastern valley portions of the Riverside and San Bernardino Zones are to be redesignated as the Eastern Zone, effective July 1976. In this report, the Zones are designated by their county names. A. Routine Air Monitoring of Sulfates Sulfate monitoring in the South Coast Air Basin is performed or supported by the SCAPCD, the Air Resources Board (ARB), and the U.S. Environmental Protection Agency (EPA). The first routine monitoring of ambient sulfate levels was started by the National Air Surveillance Network (NASN). In California, the NASN began operation at downtown Los Angeles and Pasadena in 1954. Since then, the Network has expanded its monitoring program to ten sites in the South Coast Air Basin. The NASN network in Southern California is now operated by the ARB under contract with the EPA. In an effort to relate pollutant levels with adverse health effects in Southern California, the EPA initiated the Conmunity Health and Environmental Surveillance System (CHESS) in 1972. In the CHESS program, sulfates are monitored at six sites in the South Coast Air Basin. In the NASN and CHESS programs; sulfate concentrations are determined from 24-hour high-volume filter samples on glass-fiber fflters. The NASN stations have sampled about every 12 days, collecting about 30 samples a year, and the CHESS stations sample on a daily basis. Foreseeing a need for information on suspended particulate levels, the Los Angeles and San Bernardino County Air Pollution Control Districts (APCD) began monitoring ambient air for total suspended particulate matter, sulfate, nitrate and specific metals in 1965. Riverside County APCD started a particulate matter sampling network in 1974. By 1975, the Los Angeles Zone of the SCAPCD was collecting sulfate samples at seven sites in the Basin, the San Bernardino Zone at eight sites,.and the Riverside Zone at one site. The Zones of the SCAPCD collect 24-hour samples about every six days, using high-volume samplers with glass-fiber media for collection. The validity of sulfate concentration data from the San Bernardino Zone has been questioned because of the large increase in levels measured in recent years. The staff of the Zone believes that this increase is due either to a change in volumetric flowrate of the samplers or analytical procedures; therefore, discretion should be exercised in using these data. The locations, sampling schedules, and methods of collection and analysis used by each of the agencies conducting sulfate monitoring on a routine basis are: 1. Los Angeles Zone, Southern California APCD Sampling Location and History Los Angeles 1965 to present West Los Angeles 1965 to present Hollywood Freeway 1965 &1967 Lennox 1965 to present Reseda 1965 to present Azusa 1971 to present Pasadena 1971 to present Lynwood 1974 to present Samplinq Schedule - Every sixth day
-2- Sampling Method - 24-hour high-volume, glass-fiber filters; filter brand change between 1967 and 1969 Method of Analysis - Barium chloride turbidimetric 2. San Bernardino Zone, Southern California APCD Sampling Location and History San Bernardino 1965 to present Redlands 1965 to present Ria 1to 1965 to present Chino 1965 to present Ontario 1965 to present Fontana 1970 to present Big Bear 1970-73 Crestline 1970 to present Upland 1971 to present Sampling Schedule - Every sixth day Sampling Method - 24-hour high-volume, glass-fiber filter Method of Analysis - Barium chloride turbidimetric 3, Riverside Zone, Southern California APCD Sampling Location and History Riverside - 1974 to present Sampling Schedule - Every sixth day Samp 1i ng Method - 24-hour high-volume, glass-fiber fi 1ter Method of Analysis - Barium chloride turbidimetric 4. National Air · ce Network NASN Environmental rotection A Sampling Location and History Los Angeles 1954, 57-63, 65 to present Pasadena 1954-56, 62, 64, 68 to present Burbank 1960, 64, 66, 68 to present Santa Barbara 1962-64 Glendale 1965, 67, 68 to present Long Beach 1965, 67, 68 to present
-3- Torrance 1969, 70, 72 to present San Bernardino 1968 to present Riverside 1968 to present Ontario 1968 to present Santa Ana 1969, 70, 72 to present Sampling Schedule - Every twelfth day
Sampling Method - 24-hour high-volume, glass-fiber fi 1ter Method of Analysis - Methylthymol blue (1971-present); barium chloride turbidimetric (1954-1970) 5, _Communit Health and Environmental Surveillance S stem CHESS Human Studies Laborator National • Research Center Environmental Protection A Samp 1i ng Location and History Santa Monica 1972 to present Thousand Oaks 1972 to present Anaheim 1972 to present Garden Grove 1972 to present Glendora 1972 to present West Covina 1972 to present Sampling Schedule - Every day Sampling Method - 24-hour high-volume, glass-fiber fi 1ter Method of Ana 1ys is - Methylthymo1 b1ue B. Aerosol Studies To better understand the origins and evolution of the suspended particulate matter in the atmosphere, commonly referred to as aerosols, the ARB has conducted and is conducting several research programs with emphasis on learning more about the nature of the visibility reducing haze that forms in the South Coast Air Basin. Sulfate particulate matter is one of the components of the aerosol that contributes to this degradation of visibility. 1. Aerosol Characterization Experiment (ACHEX) 1 In the Fall of 1971, the ARB sponsored a major experimental program to investigate the sources and evolution of aerosols in urban air. The project, conducted by Rockwell International's Science Center, is known as the California Aerosol Characterization E~periment or ACHEX.
-4- The initial phase of the study was directed toward the develop ment of methods and systems for the acquisition of a variety of data characterizing aerosols. The second phase concentrated on the analysis of aerosols on days which were predicted to have high oxidant concentrations. The air monitoring program used an elaborately instrumented mobile laboratory which was stationed at several sites selected to provide information on air quality in source areas, receptor areas and non-urban areas with marine and desert backgrounds. During the first phase of the project (1972), the mobile laboratory operations were supplemented by the permanent monitoring stations at Riverside and Pasadena in the South Coast Air Basin and at San Jose in the San Francisco Bay Area Air Basin. During the second phase (1973), the stations in the South Coast Air • Basin were replaced by four stations: Anaheim, downtown Los Angeles, Pomona, and Riverside, The basic air monitoring programs at these sites were supplemented by two-hour sequential samplers for inorganic and organic aerosols and by nephelometers. The locations of the mobile laboratory sites were: ACHEX Phase I Pasadena August-October 1972 Riverside August-October 1972 Harbor Freeway September-October 1972 Pomona October 1972 · ACHEX Phase II Pomona August 1973 West Covina July-August 1973 Dominguez Hills September-October 1973 Riverside August-September 1973 During both phases, suspended particulate matter samples were collected for two-hour and 24-hour periods and analyzed for sulfate and elemental sulfur. Samples were collected on cellulose filters using high-volume samplers, teflon foils, stjcky_y_oly- _ ethylene foils, Lundgren impactors with glass-fiber after-filters,· and total filters (membranes). The barium chloride turbidimetric and AIHL microchemical methods were used for the analysis of sulfates. X-ray fluorescence was used for the analysis of total sulfur and electron spectroscopy.for chemical analysis (ESCA) was used to quantify reduced or excited states of sulfur.
-5- Although the ACHEX program provided valuable information on aerosols, the duration of sampling was brief and discretion should be exercised in using the results of the study as generally representative of the characteristics of aerosols in the South Coast Air Basin. Some of the analytical results are contained in Tables III-8 and V-2 and Figures Ill-3, V-2, V-3 and V-4. 2. Air Resources Board Monitoring Program To continue the objectives of the ACHEX program, the Atmospheric Studies Section of the Air Resources Board initiated an air monitoring program to collect data on aerosol concentrations in the South Coast Air Basin. The objectives of the program were to determine the chemical composition, diurnal variation and geographical nature of aerosols. Monitoring began in the • summer of 1973 and is continuing. The sites and the periods of monitoring are: Los Angeles Summer 1973, 74 to present Pomona Summer 1973, 74 to present Riverside Summer 1973, 74 to present Anaheim Summer 1973 El Monte Summer 1974 to present Sequential two-hour samples were collected using low-volume samplers with glass-fiber filters during 1973, but, because of the un reliability of the results obtained with glass-fiber filters, membrane filters were introduced in 1974. During the summer of 1973, samp 1es were co 11 ected almost daily between 0400-1800 hours at.four selected sites. During the summer of 1974, one of the monitoring sites was replaced and samples were collected between 0600-1600 hours for about 15 to 22 days each month. The samples are being analyzed by x-ray fluorescence, which is specific for the determination of total particulate sulfur; however, the results are expressed as sulfate since most of the ambient total particulate sulfur is sulfate. Summaries of the data are shown 1n Tables III-9 and V-3.
3. Regional Monitoring of Smog Aerosols 2 In a program initiated by the ARB in 1973, the Crocker Nuclear Laboratory, University of California at Davis, is developing a method to measure the elemental composition and size distribution of atmospheric aerosols in California. The purpose of these measurements is to establish the concentrations of medium and heavy elements in aerosols, to identify natural and manmade
-6- aerosol sources, to correlate aerosols with visibility, to identify transport patterns of aerosols under a variety of weather conditions, and to provide a warning of high concentra tions of contaminants such as lead or mercury. The initial sampling network consisted of 14 sites, four of which were located in the South Coast Air Basin. In 1975, the number of sites was reduced to 11, with five sites in the South Coast Air Basin, The locations and periods of monitoring are: Azusa 1973 Los Alamitos 1973-74 Los Angeles 1973 to present Riverside 1973 to present • San Bernardino 1974 La Habra 1975 to present Temple City 1975 to present Lennox 1975 to present A modification of the Lundgren impactor was chosen as the monitoring device so that elemental, chemical and optical analyses could be made of a number of particle size ranges for each aerosol sample. Particle size separation was achieved in three ranges, using mylar-coated two-stage rotating drums with after-filters, Based on recent studies which found that the size distribution of aerosol particles is bimodal, one particle size cut-point between stages was set at approximately 3.0 microns, The three size ranges collected were 20 to 3.6, 3.6 to 0,65, and 0.65 to 0,1 microns. Analysis of the samples for elements sodium through lead, including sulfur, was performed by ion-excited x-ray emission (IEXE). The information obtained is being reduced to determine minimum, average and peak values of each element. C. Freeway Studies The catalytic converters on 1975 and subsequent model-year motor vehicles, which oxidize hydrocarbon and carbon monoxide exhaust emissions, also oxidize much of the sulfur dioxide in exhaust gases to sulfates, The increased sulfate emissions from these cars have been of considerable concern, particularly in areas of heavy motor vehicle traffic. Several studies have been or are being conducted to determine the contribution of sulfates from catalytic-equipped vehicles to ambient air concentrations. 1. Freeway Aerosol Study3 Sponsoring Agency - California Air Resources Board
-7- Conducting Agency - Crocker Nuclear Laboratory, University of California at Davis Objective - The purpose of the "Freeway Aerosol Study," was to examine the contribution of vehicular emissions to airborne particulate matter, especially in the vicinity of freeways, and to assist in developing a simulation model of particulate matter concentrations for various freeway cross-sections. Although the study dealt mainly with lead concentrations, elemental sulfur concentrations were also measured. Summary - Suspended particulate matter samples were collected on nine days during February to August in 1972, at four locations: two sites on the San Diego, one on the Harbor, and one on the Santa Monica Freeway. Sampling was done with four-stage rotating drum Lundgren impactors fo 11 owed by a fifth-stage after-filter, one instrument upwind of the freeway, and four downwind. The • sampling period was two hours. Only data obtained when the wind direction was approximately 45° to the freeway were used in the analysis. The particulates on the impaction media and filters were analyzed for several elements, including sulfur, by ion induced x-ray fluorescence analysis. The free~iay contribution of particulates to the atmosphere was obtained by subtracting upwind from downwind concentrations. Results of the analyses indicated trace contributions of sulfur particles greater than about 0.5 µmin diameter due to freeway traffic. The Whatman 41 cellulose filters used for sampling were found to pass particles less than about 0.5 µm. Therefore, it is probable that some sulfur was not measured. 2. Sulfur Dioxide Conversion Study4 Sponsoring and Conducting Agency - California Institute of Technology Objective - The Sulfur Dioxide Conversion Study was conducted to determine the conversion rate of sulfur dioxide to sulfate particles and to estimate the impact of catalytic converters on sulfate levels in urban atmospheres. Summary - In this study, sulfur dioxide and sulfate concentra tions were measured near major stationary sources (Dominguez Hills) and at a downwind receptor site (Pasadena) in the Los Angeles Basin. Samples of particulate matter were collected for one-hour periods using a total filter sampler and a cascade impactor and analyzed by a newly developed technique of sulfur volatilization. Gas phase sulfur was monitored continuously ~11th a flame photometric detector, coincident with the particulate sampling.
-8- The particulate-to-gas-phase sulfur ratios obtained at source and receptor sites were used to estimate the apparent S02 to so conversion rates. These rates ranged from 1.2 to 13.0 percent/ hour,4 with a mean value of 7.1 + 3.8 percent/hour, based on data taken on three days in July 1973. Some calculations were made to estimate the probable influence of auto exhaust catalytic converters on sulfate levels near roadways and at the receptor sites. In making these calculations, it was assumed that all cars were equipped with catalytic converters, the conversion of sulfur in gasoline to sulfate by each car was 50 percent and gasoline contained an average of 0.075 percent sulfur. Under these assumptions, an increase of 76 µg/m3 in sulfate, above the levels due to other sources, was estimated for areas near freeways at rush hour. Approximately a 10 percent increase in the ambient sulfate level was predicted for Pasadena, after the introduction of two model years of catalyst equipped vehicles. 3. Impact of Motor Vehicle Exhaust Catalysts on Air Quality5 Sponsoring Agency - California Air Resources Board ConductinT Agencies - Air and Industrial Hygiene Laboratory (AIHL) of the Ca ifornia Department of Health, Rockwell International Science Center and U.S. Navy Weapons Center (China Lake). Objective - This study was initiated to establish the contribution of automobile traffic to roadside concentrations of particulate sulfate, nitrate and ammonium as catalytic converters come into use. Samples are collected for certain months of the year next to a major freeway. This three-year project began in 1974. Summary - In the initial phase, measurements of sulfate and total sulfur were made from August to September of 1974, prior to the introduction of catalyst-equipped cars, so that a baseline for sulfate concentrations near roadways could be established. Data were obtained by sampling on both sides of the San Diego Freeway in West Los Angeles. Two mobile research laboratories were used, one upwind and one downwind of the freeway. Because of the prevailing westerly wind, the sulfate contribution due to the freeway traffic was determined by subtracting the upwind (western side) sulfate concentration from the downwind (eastern side) sulfate concentration. The sampling was performed on 12 days during the two-month period, using total filter samplers with membrane filters to collect particulates less than approxi mately 20 µmin diameter and cellulose filters to collect particulates in the refined range of less than approximately 3.5 µm. Samples were collected for two-hour periods between
-9- 0600-2000, each day, X-ray fluorescence was used for the analysis of total sulfur; and the methylthymol blue and AIHL microchemical methods were used for the analysis of sulfates, The sulfate concentrations ranged from a low of two µg/m 3 to a high of 36 µg/m3, The elemental sulfur particulate values ranged from one to 14 µg/m3. An analysis of the total particulate (<20 µm) sampler data indicated that there was no sulfate attributable to vehicular traffic, The refined particulate (<3,5 µm) sampler data indicated only a small contribution of about T.4 µg/m3, which was considered to be within experimental error, due to the differences in flow calibration between the two samplers. The results suggested that preliminary field evaluations of the equivalence of the samplers be made before future monitoring is conducted, Comparison of expected and_observed ammonium levels indicated that all of the NOj and so can be accounted for as ammonium salts, suggesting no acids 4were present. Approximately 65 percent of the sulfate particulates collected were found to be in the size fraction .::_3,5 µm. Because of sampling errors, this figure is a lower limit value, The present data indicate that only a few percent of the sulfur are present as sulfides or elemental sulfur. 4, Los Angeles Catalyst Study6 Sponsoring Agency - Environmental Protection Agency (EPA) Conducting Agency - Environmental Monitoring Branch (EMB) of the Environmental Monitoring and Support Laboratory (EMSL) Objectives - The purpose of the Los Angeles Catalyst Study (LACS) was to obtain ambient sulfate data before and after the intro duction of the 1975 model-year automobiles in order to determine if the catalytic converter is a significant sulfate emission source, especially in areas adjacent to heavily traveled freeways. Surrmary - Monitoring was conducted adjacent to the San Diego Freeway, between Sunset and Wilshire Boulevards. High volume samplers were placed at locations 100 and 25 feet east and 25 and 110 feet west of the edge of the freeway, The monitoring began in June 1974 with four-hour (6-10 a.m. and 3.7 p,m.) and 24-hour sampling periods at each site. Thus, it was possible to compare several combinations of pairs of cross freeway concentrations. The high-volume samples are analyzed for total suspended particulate matter, ammonium, lead, nitrate and sulfate, Concentrations of carbon monoxide, oxides of nitrogen, nitrogen dioxide, sulfur dioxide and total sulfur are also measured at each site.
-10- The study defined a favorable sampling period as a period during which the average carbon monoxide (CO) concentration at the downwind site divided by the average CO concP.ntration at the up wind site was greater than or equal to two. Conditions least favorable for collecting samples occurred during periods when the wind direction was parallel, rather than perpendicular to the freeway. These occurrences were most prevalent in December, January, and part of February. Sometimes, conditions during the morning were also unfavorable. For the first twelve months, monthly avjrage sulfate concentra tions ranged from about four to 24 µg/m for the 24-hour • intervals, 16 to 35 µg/m3 for the 6-10 a.~. (changed to 8-12 a.m. January 1975) intervals and 10 to 32 µg/m for the 3-7 p.m. intervals. The differences between upwind and downwind sulfate concentra tions indicate that there was no statistically significant contribution of sulfate originating from the freeway in late 1974 and early 1975. The data did indicate occasional trace increases of sulfate concentrations between sites, but there were no consistent patterns. This lack of increase in sulfate was foreseen for two reasons. First, the percentage of catalyst equipped motor vehicles was low. Only one-half to one percent of the Los Angeles area motor vehicles were catalyst-equipped (estimated at two or three percent by the end of February 1975). Second, meteorological conditions from November through February were not conducive to identifying an increase in sulfate. 5. Air Resources Board Freeway Monitoring Study Sponsoring Agency - California Air Resources Board Conducting Agency - Atmospheric Studies and Air Quality Surveillance Sections of the ARB. Objective - The purpose of this study is to monitor some of the pollutants associated with motor vehicles, giving special • attention to the effects of catalyst-equipped vehicles on the ambient air.
• Su!TITiarf - The ARB is conducting studies at three locations, on the Ho lywood, San Diego and Riverside Freeways. The Hollywood and San Diego Freeway studies are being conducted by the Atmospheric Studies Section of the ARB and the Riverside Freeway study is being conducted by the Air Quality Surveillance Section. a. Hollywood Freeway Study This study was initiated in March 1975 to monitor concentra tions of carbon monoxide, sulfur, lead, vanadium and other metals. Sampling is being conducted on the roof of a building located between the north and southbound lanes of the Hollywood Freeway near Vennont Avenue. In August 1975, a reference
-11- site ~1as added a few hundred feet upwind, on the roof of another building. Both of the buildings are at about the same height as the elevated freeway. The aerosol samples are collected for two-hour periods using sequential samplers and the elemental concentrations . of the samples are determined by x-ray fluorescence. Sulfur concentrations are expressed as sulfate. The two-hour sulfate concentrations for the period f om March to July 1975 ranged f§om about three to 75 ~g/m 3 with a mean of about 22 ~g/m at the do~:nwind site. Simultaneous sampling at the two sites began in August and an evaluation of this • data, which is currently underway, will determine if the freeway is contributing significant amounts of sulfate to the ambient air. b. San Diego Freeway Study Since May of 1975, the ARB has been sampling at the San Diego Freeway near Ohio Avenue, between Santa Monica Boulevard and Wilshire Boulevard, using a mobile van. This is the same site used by Rockwell International (page 9). Continuous measurements are made to determine concentrations of carbon monoxide, total hydrocarbons, sulfur dioxide, nitric oxide, nitrogen dioxide, and oxidant. Solar radiation, relative humidity, temperature, b-scat (light extinction coefficient resulting from scattered light), wind speed and wind direction are also measured. Aerosols are monitored for two-hour periods using sequential samplers on the roof of the van located 20 feet east of the freeway, and at another site several hundred yards west of the freeway. Analysis of the particulate matter samples, as in the case of the Hollywood Freeway study is performed by x-ray fluorescence. From May to July 1975, the two-hour sulfate co~centrations at both sites rang d from about five to 96 µg/m , with a mean of about 29 µg/m 3, and indicated a • small but statistically significant contribution of sulfate from the freeway. c. Riverside Freeway Study Near the Riverside Freeway, high-volume samples are being collected every third day, at t~JO sites - 7002 Magnolia Avenue and 3044 Horace Avenue in Riverside. The Magnolia site is about one mile west (upwind) and the Horace Avenue site is about one-half mile east (downwind) of State Highway 91. From May through September 1974, samples were collected on both cellulose and glass-fiber filters and analyzed for lead, sulfates and total suspended particulate matter. Similarly,
-12- samples were collected on both media from March through June of 1975 and analyzed for the same materials, plus nitrates and organic matter. The samples collected initially will provide a baseline to determine the net sulfate contri bution from catalyst-equipped motor vehicles in future years. The results of the Riverside Freeway sampling during 1974 and 1975 shown in Table II-1 were similar, though the monitoring took place during different periods of the year. Lead concentrations upwind, during both years, were found to be higher than downwind, the reverse of what was expected . • Total suspended particulate matter also showed· a similar pattern, but to a lesser extent. The higher concentrations of lead at the upwind site are believed to be due to nearby street traffic, which may be heavier than the freeway traffic. Sulfate concentrations observed during 1974 indicated a slight, but not statistically significant increase in downwind levels over upwind levels. The data for 1975 does not show this effect. Sulfate concentrations in 1974 and 1975 ranged from about three to 42 µg/m3 and three to 28 µg/m3, with monthly means of about 13 µg/m3 and 11 µg/m3, respectively. Average concentra tions for comparable months (May and June only) at both sites indicated an increase from 12.3 to 13.1 µg/m3 from 1974 to 1975, using th~ glass-fiber filters, and an increase from 11.5 to 14.3 µg/m from 1974 to 1975, using the cellulose filters. Additional air monitoring is planned at all three sites •
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TABLE II-1 ARB RIVERSIDE FREEWAY STUDY 1974 & 1975
Statistical Summary*
Mean Mean Significance of the Difference Upwind Downwind Between Downwind and Concentr~tion Concentr~tion Upwind Concentrations (µg/m ) (µg/m) at the 95% Confidence Level Pollutant 1974 1975 1974 1975 1974 1975 Sulfate (Cellulose filter) 12 .11 l 0. 64 12 .81 l 0. 85 No No Sulfate (Glass-fiber filter) 13 .14 l 0. 43 13 .47 9.99 No No Lead (Cellulose filter) 2.05 l. 41 1.47 0.98 Yes Yes Lead (Glass-fiber filter) 2.73 l . 59 l .81 1.12 Yes Yes I ~_,,. Total Mass (Glass-fiber filter) 150. 4 127. 3 143.6 126. 7 Yes No I * 1974 Data for May-September period (44 paired observations for all, except lead on cellulose, 10 pairs) 1975 Data for March-June period (29 paired observations for sulfate and lead, 31 paired observations for total mass).
Comparative Summary Average of Upwind and Downwind Concentrations May-June 1974 &1975
.·• ~·:, . .~- . . Mean ·-.~... · }/· . Concentr~tion (µg/m ) Pollutant 1974 7975 Sulfate (Cellulose filter) 11 .5 14.3 Sulfate (Glass-fiber filter) 12. 3 13 .1 Lead (Cellulose filter) 1.2 1.3 Lead (Glass-fiber filter) l. 5 Total Mass (Glass-fiber filter) 133 153 .,r' . ~ . ;: ! · ,- \'.
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•
' III. SULFATE CONCENTRATION DATA A. Bae kg round Levels Atmospheric sulfate concentrations consist of contributions from both anthropogenic and natural sources. The portion from natural sources constitutes the background level and includes material from several sources. The ocean is probably the primary source. Sulfur reducing bacteria in the ocean produce hydrogen sulfide, which is oxidized to sulfate by dissolved oxygen; the sulfate is then trans • ferred to the air as sea spray. Another natural source is decaying plant and animal tissue, from which hydrogen sulfide, dimethyl sulfide and other organic sulfur containing gases are released. These compounds are subsequently oxidized to sulfates in the atmosphere. Small amounts of sulfur-containing gases are also emitted from hot springs and volcanoes. The estimated global background level of sulfate, which would ex!s B in the absence of anthropogenic contributions, is about two µg/m. 7• Aerosol studies of sulfates in the South Coast Air Basin hgve shown the background level there to be approximately four µg/m3,9 B. Ambient Levels 1. Annual and Monthly Average Concentrations Since sulfates are not monitored for periods exceeding 24-hours, annual and monthly average concentrations are determined by averaging the available 24-hour concentrations for the specified period. The number of 24-hour samples comprising a monthly average generally ranges from two to 30. For an annual average concentration, the number of samples generally ranges from 25 to 360. The number of samples in the average depends on the sampling schedule of the monitoring agency. The National Air Surveillance Network usually collects two to three 24-hour sulfate samples a month or 25 to 30 a year; the local Zones usually collect five to seven samples a month or 60 to 80 a year; the Community Health and Environmental Surveillance System collects samples daily. Annual and maximum monthly average sulfate concentrations for the years 1965 to 1975 are shown in Tables III-1 and III-2; These concentrations typically (excluding San Bern~rdino data - see page 2) range from ~bout five: to 20 µg/m on an annual average basis and 10 to 45 µg/m on a monthly average basis. The geographical distribution of the highest annual average sulfate concentrations in the Basin for the period of 1972 to 1974 is shown in Figure III-1. These concentrations appear fairly uniform across the Basin, but the highest averages are generally in the inland areas.
-15- 2. 24-Hour Concentrations Ambient sulfate concentrations are monitored routinely by the Los Angeles and San Bernardino Zones of the SCAPCD, NASN and CHESS. The maximum 24-hour concentrations for data collected from 1965 to 1975 are shown in Table III-3. These concentrations typically range from about 20 to 80 µg/m3. The individual . 24~hour concentrations col 1ected before 1975 by the San Bernardino · . Zone are not available, because analyses were performed on a ~omposite of samples for three month periods . . .Siilfate concentrations during the third quarter of the year have · specfa.l significance because the levels are generally high at . ·the .same time oxidant concentrations are often high. Some . statistics of the sulfate data during this period are shown in . the)ollowing tables. Table III-4. Maximum 24-Hour Sulfate Concentrations . ·.. Table III-5. Average of the Monthly Maximum 24-Hour Sulfate Concentrations .Table III-6; Average 24-Hour Sulfate Concentrations Table.III-?. Percent Frequency Distribution of 24-Hour Sulfate Concentrations The geographical distribution of the maximum 24-hour sulfate concentrations in the Basfn for 1972 to 1974 is shown in Figure III-2. The data indicate that sulfate concentrations in inland areas are relatively higher than those in coastal areas. 3. Two-Hour Concentrations Concentrations of sulfates were monitored for two-hour periods at various locations in the Basin during selected months of 1972 to 1974 in the Aerosol Characterization Experiment (ACHEX) and in the ARB aerosol monitoring programs. • A summary of the two-hour sulfate samples in the ACHEX study is shown in Table III-8, together with a summary of 24-h~ur samples. The two-hour levels range from zero to 70 µg/m with a mean of about 20 µg/m3. The two-hour samples collected by the ARB, shown in Table III-9~ show similar results, with a range from about tv10 to 75 µg/m . The geographical distribution of the maximum two-hour sulfate concentrations in the Basin is shown in Figure III-3.
-16- TABLE 111-1 '
ANNUAL AVERAGE SULFATE CONCENTRATIONS SOUTH COAST AIR BASIN (Micrograms Per Cubic Meter)
·llil ill§. 1967 ~ 1969 1970 ill! 1972 lfil !fil 1975 Anahefm-NASN 9,7 9,8 10,7c 9,5c 12.st NA Anaheim--CHESS 10. JC 12.,c 10.zc 11 .2c Azusa lJ,56 15,8 12.9 10.8 10.9
9,4. 9,5lC Burbank-NASN -- 3 11,0 9.] 8,16 11. 2c 14,gc 18,;c NA Chino'. 4., 8,2 2.8 11.4 4,0 11,7 15. 1 20,5 30.4 11.91 Crestl fne * 6,5 6,8 13,5 15.9 5.6
Fontana"' 12.2 14.7 24,0 28.B 12.2 4 Garden Grove-CHESS 9.2 C 13.0c 10.8~c 10,4< Glendale-NASN 10.5 12.3 10.8 11,2 . 8.8 10,JC l0,4C 9.0 NA
G1tndora-CHESS -- 1' -- 11. le 14,2c 10,51< 9.sC \!ollywood Frwy, 7.rl 8.3, -4_96 7 -- Lennox 6.8 8,3 · 9.8 8,8 13,4 13.5 14.8 14.8 13.4 11.6 12,4
Long Beach-NASN 14,9 13.4 15.3 · 14.4 8.6 11.t 10.6° 14,olc NA -9.71 Los Angeles 10,37 11,3 8.8 16.2 14.8 16.2c 14. 9c 15.Jc 12.~ 12.2 Los Angeles--NASN 14.4 8.0 12. l 12.9 11,2 13.2 10.5 11. 1 12.3 13,9 NA
f.ynwood 9.8 10.2 Ontario* 5.7 4,9 2.3 12.4 1.3 11.2 15.9 16.1 28.9 NA Ontario-NASN 9.9 11,9 . 8.5 1o.11' 10.st 13_75c NA
Pasadena 10.8$ 12.3 13,f 9,2 10,8 Pasadena-NASN 10,8 · lz'.2 12, l 11. 9 2C' 13, 11. 53c NA -j,93 1 Redlands* 9,8 1.7 10.1 3.7 12.0 13.2 17,0 23.4 7.e •
Reseda* 8.~ 5.8 10.8 10.3 13.0 16.9 15,8 10.5 10 .1 Rialto 5.1 3,3 2.7 11.5 2,3 17 .2 17,0 24,4 34,1 11.8 Riverside 15,3 NA
Rfversfde--NASN 9,8< 13.lc 8.9 11,43c -s.53 NA San Bernardino* 3.5 2.2 8,5 3.9, 11.2 12.4 19.0c 25.4c 10.9 San Bernardfno--NASN 9.8 14,5 11.5 11. ,c 15.7 12.3 NA
Sa.nta Ana-MSN ·9,8 9;4 11,7 8,0 11.5 NA Santa Monica-CHESS 4 9.4~ 12,4< 11 33C 9.66c Thousand Oaks-CHESS 8.1 10,9< . 8·,3c 8.a6c
Torrance-NASN 10,7 8,2 11,Bc 11,zC 11,6c Upland" NA 11,3 15, 14c 21,8c 33.0lC NA West Covina-CHESS 11. 0 14.2 11,1 11.5c
8 3 West Los Angeles 9,0 6, 1 5,6 3,2 9.0 9.4 9,4 11,9 10.3 8,8 9,3
-Numerical exponents represent mor.ths of m1ss1nq data fn specified period. c-Su1fate by methylthymol b:ue ana1ys1s; all others by barium chloride turb1d1metr1c analysis. NA-Data not available. ••Analysis of sulfates by the San eernard1no Zone bPfore 1975 are for a seasonal year (Decem~er 01" pre.vious year to Nov~ber of computed year) ar,d are <1uarterly composited (e.g.' 3rd quarter 1s composite of June, July and /l.ugust data).
ARB 1975 -17- • TARLE 111-2 MAXIMUM MONTHLY AVERAGE SULFATE CONCENTRATION SOUTH COAST AIR BASIN (Micrograms Per Cubic Meter)
1965 1966 1967 1968 1969 1970 1971 1972 1973 1971 1975
Anahe1m-NASN 20.ac 22, 1 C 20.6c 17 ,4C Anaheim-CHESS 6 Azusa zj_ , 35,0 29,4 25,9 19.9
Burbank NA 21.5 Chino• 1 Crestl 1ne• 10.4
Fontana• 19.9 Garden Grove-CHESS iz.64c 23. le 18.,c 11.oc G1 endal e-NASN
0 23.9C 32,7C 21.41 C 15.9 C Glendora-CHESS -- 7 -- 1 6 Hollywood Frwy 15, 47 15.2 9.0 Lennox 14.3 15.52 21.7 16.6 27.7 23.2 27.4 23.4 31.5 25.0 21.0
Long Beach-NASN Los Angeles 19.77 ia.11 20.8 15. 7 28,5 24.9 31.7 32.7 32,3 24.7 19.4 Los Angeles-NASH
Lynwood 23.5 17.2 Ontario* NA Ontario-Nft.SN
6 Pasadena 20.1 24.2 26.6 20.0 19.6 Pasadena-NASN 1 Redland~ ii.1
8 Reseda 16.2 12.B 20,4 17.1 26.0 45.8 39,0 24.0 19.5 Rf alto* 20.7 Riverside 28.6 NA
Rfverside-NASN San BernardinO"' 19.2 San Bernardino-NASN
Santa Ana-NASN Santa Monica-CHESS i2_74c 22.7c is.43c iz.85c 6 Thousand Oaks-CHESS 14.1 4c 22.oc 1a,9c 12. 4 c
Torrance-NASN Upland• NA West Covina-CHESS j5. 74c 34.0c 20.91c ,a.sc
8 3 West Los Angeles 16, 6 11.5 10.8 5.5 18.7 23.1 15.7 21.6 25.1 20.8 16.1
-Numerical exponents represent month~ of mfssfng data fn specified period. c-Sulfate by methylthymol blue analysis; all others by barium chloride turb1dimetr1c analysis. NA•Oata ~ot available. *•Analysis of sulfates by the San Bernardino Zone bP,fore 1975 are for a seasonal year {December of preVious year to NOVe""~er of computed year) and are auarterly composited (e.g. 3rd quarter is composite of June, July ind August data). •NAS~ ~ata are not shown d•Je to 1nsuff1c1ent samples.
ARB 1975 -18-
TABLE 111-l
MAXIMUM 24-tlOUR SULFATE CONCENTRATIONS SOUTH COAST AIR BASIN (Micrograms Per Cubic Meter)
JJ65 1966 1957 12.@. 1959 ill!l. 1971 1972 lli.L ill! 1975
Anahefm-NASN 40.1 38.4 43.Bc 21.8c 41.8c NA Anaheim-CHESS 60.Bc 65.8C 47.4c 49.oc Azusa 44.96 56.5 39.3 40.4 32.6
Burbank-NASN 2).0 38.7 49.7 43.4 3o.olc 36.9c 55.lc 45.2c NA Chino• 39.51 Crestl 1ne • -- 23.6
Fontana• 41.5c Garden Grove-CHESS 26.lc 55.7c 46.t;c 43.6 Glendale-NASN 49.5 45.5 29.3 42.7 24.0 37.9c 36.0c 34.4 NA
Glendora-CHESS 55_5c 71. 5c 49_5lc 47.ef' Hollywood Frwy. NA NA NA Lennox 25.1 7 32.21 43.4 35.6 44.0 45.7 54.9 53.3 48.7 41.9 34.5 long Beach-NA~N 41.97 34.4 50.2 41.8 ·15.6 39.4c 27.5c 45_3lc NA Los Angeles 34.0 ii.21 · 34.6 47.2 45.5 44.5 56. 1C 55.5c 72.2c 44.5 36.3 Los Angeles-NASN 40.7 21.4 53.6 41.2 25.2 40.5 29.5 40.7 28. 1 50.9c NA
Lynwood NA 34.9 0ntarfO" NA Ontarfo-NASN 18.0 35.3 22.Z 21.sc 28.ac 29.1 5c NA
6 Pasadena 35.1 48.4 c 44. 1 37.0 c .34.0 Pasadena-NASN 35.0 40.7 28.6 32.4 2 42.5c 40.4 3 NA Redlands• 25.01 8 Reseda 20.2 25.J 43.3 36.8 54.0 69.4 50.3 45.2 31.2 Rf alto* Rfversfde 39.8 :i ·' 3 Rfverside-NASN 36.5 28.2 21.0 26.6 c NA San Bernardino"' -- 1 29.4 San BernardinerNASN 35.8 31. 7 46.7 33.3c 6s.i2c 35.9c NA
Santa Ana-NAS'N 26.6 24.4 60.94 17.5 34.6 NA Santa Monica-CHESS 42.1 C 49.oc 56.33C 51.95c Thousand Oaks-CHESS 84.6~c 68.4c 47.Bc 28.96c
Torrance-NASN 32.6 25.0 29. 1C 33.0c 29.5c Uplanctr- NA West Covina-CHESS NA 48.84c 62.5c si.,1c 59.7°
West Los Angeles NA NA NA NA NA NA NA NA NA NA 32.8
-Numerical exponents represent months of missing data 1n spec1f1ed period. c-Su1fate by methy1thymo1 blue analysis~ all others by barium chloride turb1d1metr1c ana1ys1s. NA•Oata not available. •-Analysis of sulfates by the San 8ernard1no Zone befor'e 1975 are for a seaso.,al year (December of previous year to November of co~outed year} and are quarterly composited {e.g. 3rd quarter 1s composite of June, July and August data).
ARB 1975 -19- • TA6LE 111 •4 MAXIMUM 24-HOUR SULFATE CONCENTRATIONS SOUTH COAST AIR BASIN JULY, AUGUST, ANO SEPTEMBER (M1crograms Per Cub1c Meter)
1974 lfil_ I.ill. 1966 1.921. ~ 1969 lliQ. lfil lill. !fil
40.1 20.B 13,9< 21.e< 41.Bc NA Anahe1m-NASN 26, 1< 65.e< 47 .4' 43,o< Anaheim-CHESS 39,3 39.7 31.4 Azusa 37.2 34.2
49.7 18,4 11,11< 15.2< 55,3< 45.2c NA Burbank-NASN 21.4 19.9 32.5 Chino* 9.0 Crestl 1ne* 33.3 Fontana* 2s.3< 43.6c 45,2< 43.6C Gard~n Grove-CHESS .42< 15. 1< 36.0' NA NA Glenda1e-NASN 1B,3 25.1 18.2 42.7 21.0 ii
46,5c 62,o" 49,5" 3Q,4C Glendora-CHESS NA Hollywood Frwy. NA NA 48,7 41.9 34.3 Lennox 25.1 l 15. 0l 35.B 35,6. 37.9 45.7 40.6 27.0
12.s< 27,SC 45_3< .NA Long Beach-NASN 41.9 l 24.0 24.9 22.0 15,6 1 32.0 47,2 45.5 43.8 47.9 34.4 44.4c 3B,9 31.0 Los Angeles 34.0 i1 .9 14,3< 50,9' NA Los Angeles-NASN 40,7 13.8 17 .7 21. 5 19. 6 40.5 22.0< 24.2 NA 29.4 Lynwood NA Ontario* -e,5< 26.31< is, 92C NA Ontario-NASN 16.0 35.3 22.2
Pasadena 35.1 28.4 39,5c 31.3 29.8 28.6 25.6c 42.5 NA Pasadena-tlASN 17.9 20.0 15.4 Redlands*
17 .22 25,7 35.2 27 ,9 35.0 40.4 50.3 40.5 25.3 Reseda 41.7 Rialto* 1 R1vers1de ji .2 NA
R1vers1de-NASN 17.3 28.2 19.5 11.alc 21,51c NA San Bernardino* 1 27.4 San Bernardino-NASN 20.9 31.7 26.3 iii.1< ss.3< JS.BC NA
Santa Ana-NP.SN 25.8 22.1 10.7 15.4 34.63 NA Santa Monica-CHESS 20.0< 41,5< 56,3 C NA Thousand Oaks-CHESS 24.Bc 55,5< 47 ,ec 2B,9C
Torrance-NASN 32.0 15,5 14. 1< 33.0c 29,5< NA Upland* NA West Covina-CHESS 48.s" 62.s" 53,71c 44.9<
West Los Angeles NA NA NA NA NA NA NA NA NA NA 32.B
-Numerical exponents represent ~onths of missing data in specified period. c•Su1fate by methylthymol b1 ue analysis; all others by barium chloride turb1dimetric a.nalysis. NA-Data not available. ••Analysis of sulfates by tile San Bernard1no Zone bPfore 1975 are for a seasonal year {December of' pre.v1ous year to NoveMber of computed year) and are quarterly comoos1ted {e.g. 3rd q~arter 1s compos1t~ of June, July and August data).
ARB 1975 -20-
TABLE 111-5 AVERAGE OF THE MONTHLY MAXIMUM 24-HOUR SULFATE CONCENTRATIONS SOUTH COAST AIR BASIN JULY, AUGUST ANO SEPTEMBER (Micrograms Per Cubic Meter)
1965 1966 1967 1968 ~ 1970 1971 1972 !.fil 1974 .!lli.... 26,7 16.7 10.6c 15.2c 22.)c NA Anaheim-NASN JQ,4C Anaheim-CHESS 23, 1c 51.1c 32.7 Azusa 28.8 26.1 35.2 27.7 25,2
Burbank-NASN 14.8 17,5 27.5 16.5 16.Jlc 11.9c 36.3C 30.0C NA Chino* 28.0 Crestline* 8.4
Fontana* 24.0 37.5° 30.2" 31.o" Garden Grove-CHESS 2 23.7" Gl endal e-NASN 12. 7 18.0 16.3 24.2 15. 9 ii.4 c 11.4c 24.0c NA NA
Glendora-CHESS 31. JC 42.6° 31.a< 26.JC Hollywood Frwy. NA NA NA , Lenno:it 23.01 12. 2l 25.0 20.7 · 33.1 37,3 30.5 20.7 38.3 32.9 27.3
14.9 19.5 12.8 10,9c 22.3C 25.)C NA long Beach-NASN 27 .5, 1 19.7 Los Angeles 28.1 16.1 29.4 26.0 40.4 37.2 37.2 26.0 39.3 30.5 25,4 Los Angeles-NASN 20.9 11. 7 13.9 21.0 15.9 13.3 16.9c 12. ]C 20.0C 28.4C NA
Lynwood NA 22,1 Ontario* 20 NA Ontal"'io-NASN 15.5 20.5 18.0 ·1.1< 2i.1lc is.9 NA
Pasadena 27.5 20.8 28.3 23.5 25.2 Pasadena-NASH 15.1 18.9 22. l 17.7° 28.4c M Redlands* 14.2
2 43.0 Reseda 17.2 17.8 29.2 19,2 26.4 26.9 25.1 20.9 R1altn * ,- 22.8 Riverside 27,1 NA
10 12.5 21.5 16.7 10.8 le 19.5 NA Riverside-NASN 22.5 San Bernard1nor- 1 San Bernardino-NASN 16.7 27.4 23.7 iz,3C JS.Sc 23. 1° NA
NA Santa Ana-NASN 21.3 19.2 9,9 13.8 20.53 23.sg 36.og 35, 1 / NA Santa Monica-CHESS 30.6 22.s< Thousand Oaks-CHESS 23.4 39.0
24.3 12.0 12.0° 23.6° 18.9c NA Torrance-NASN NA Upland* 35.910 33.4° West Covina-CHESS 32.ff 47,6c
West Los Angeles NA NA NA NA NA NA NA NA NA NA 23,5
-Numerical exponents represent months of missing data 1n spec1f1ed period. c-Su1fate by methylthymol blue analys1Si all others by barium chloride turb1d1metr1c analysis. NA-Data not available. •-Analysis of sulfates by the San Bernard1no Zone bPfore 1975 are for a seasonal year (December of' pre·v1ous year to November of computed year) and are quarterly composited (e.g. 3rd quarter 1s composite of June, July and August data).
ARB 1975 -21-
TMLE 11!-6 AVERAGE 24-H~UR SULrATE CONC[NTRAl!ONS SOUTH COAST AIR BASIN JULY, AUGUST ANO SEPTEM8(R* (Hicrograr1s Per Cubic Meter)
!ill. ~ lli1. 1968 1969 1970 1971 1972 lfil 1974 lfil
Anahe1m-NASN 18.9 12.6 8.8< 11.9< 16.8c NA Anaheim-C_HESS ,, .o< 20.0' 14.9' 15.6' Azusa 18.0 15.3 24. 1 18.0 16.8
1 Burbank-NASN 13. 9 13. 1 18. 5 10.6 12.1 < 9.7< 21.8< 18.lc NA Chino* 6.0 2.6 8.6 19.6 21.0 16.S 29.5 39.5 16. 9 Crestl fne* 15.0 8.0 38.0 , 32.l 7.1
Fontana• 21.5 22.3 48.1 43.9, 15.3 C Garden Grove-CHESS 10.9~ 19.6~ 14.0 14.8 Glendale-NASH 9.3 14.9 11.0 18.2 11.2 • ii.42C I 9. 7 16. 6 NA NA
Glendora-CHESS -- 2 12.2< 24.5c 16.0c 12.1< Hollr,ood Frwy. 13.1 l 10. 11 NA Lennox 12.7 7.8 16.3 12.0 22.5 18.1 20.2 13.8 22.1 19.6 17.9
io.4 9.o< 21.0' NA Long Beach-NASN 20.11 1 14.5 14. 1 17.2 20.0' Los Angeles 16. 1 iii. 9 17. l 10.8 25.4 18.4 22.4 12.9 25.5 19.4 17 .0 Los Angeles-NASN 16.1 9.5 11.9 14.7 11.9 13.4 13.4' 10.2' 17.1' 20.5' NA
Lynwood 16.6 14.2 Ontario* 6.4 2.4 4.8 21.4 1.7 23.7 17.4 32.92' 38.2 NA Ontario-NASN 11.0 15.4 15.3 6.4' 18.5 NA NA
Pasadena 14.9 11. 6 21.8 14.4 17.o Pasadena-NASN 13.9 15.6 16. 9 14.0C 21.8' fb Redlands* 9.2 1.4 , l. 3 19.0 l. 3 24.7 10. 0 36.9 34.3 Reseda 16.22 8.2 18.3 11. l 15.1 14. 1 33.4 17.9 Rialto* 5.4 1.8 3.8 15.5 1.4 31.0 22.5 37.6 43.0 U:1 Riverside 13.9 NA
R1vers1de-NASN 10. l 17.9 14.8 13.41< NA San Bernardino• 3.8 0.9 2.7 16.1 1.91 19.4 7.6 36. 1 38.2 14.7 San Bernardino-NASN 19.4' > 11 .8 21.5 15.8 10. 1' 25.2'· NA
Santa AM-ffASN 15.6 14.9 8.o' 11.8' 16.t NA Santa Monica-CHESS 10.zC 19.3' 16. lhousand Oaks-CHESS 9.]C 18. l' 13.6" ~ts,
Torrance-NAS.N 16.4 10.5 9.3C 18.5C 16.9' NA Upland* 21.0 16.5 3B.8 53.9 NA West Covina-CHESS 12.B' 24.4' 16.6' 16.0' 2 West Los Angeles 14.5 NA 9.8 3.8 13.5 11.9 11. 9 11.4 17.6 16.7 , 14. 1
-Nureer1ca1 exponents represen~ months of m1ss1ng data 1n specified period. c-Sulfate by met~y~thymol b1ue analysis; all others by barium chloride turb1dimetr1c analysis. NA-Data not·ava11ab~e. 0 •-Analy,h of ~u1fates by ttle San Bernardino Zone b~fore 1975 11re for a seasonal year (December of ore v1ous year to r:over.iber cf comoutecl year) c1nd He ~uarterly composited {e.g. 3r"d quarter" 1s composite of June, July and August data}.
ARB 1975 -22-
•
TABLE III-? PERCENT FREQUENCY DISTRIBUTIOl! O? 24-HOUR SULFATE CONCENTRATIONS SOUTH COAST AL~ BA.SIN JULY - AUGU:l'f - :;E.J."l.'Er'illlll (Micrograms Per C~bic Heter)
Percent or Observations Ec;:.ual to or Less Than the Concentration Slto-,n. ,
1!! .i:2 .l2 40 29. fil 22 1lQ ~ ~ li ll 09 l:i lQS! J..nahe~-~A.Sli••• =· 1970c 8.7 9.0 9.3 9.9 11.1 11.z.. 11.7 1B.1 20.4 20.? 20.8 20.8 20.9 20.9 21.0 1971 ------10--.C --J.8 5.• --6.4 --8.0 9.5 9.?- 10.0 13.1 13.6- l3.8 13.s 13.9-- 13.9--- 14.0 14.0 1§,'};c 2.9 3.2 3.4 10.0 12.3 12.9 20.4 20.9 21.5 21.7 21.8 21.B 21.9 21.9 21.9 197-.,c 6.2 9.1 11.9 13.l 14.} 15.5 16.6 17.s 40.8 41.4 t.1.5 41.? 41.B 41.9 41.9 bahei:.-Cl!ESS• 1972 6.3 7.6 8.3 9.4 10.6 l'!..4 12.3 13.6 16.5 19.4 20.; 22.2 2?..? 25.3 26.l 1973 10.1 14.0 16.0 17.2 18.4 20.6 22.8 25.1 29.0 32.9 ;s.o 40.3 56.0 63.? 65.8 197-1- 6.8 8.4 9.8 11.2 12.9 14.5 16.4 2::>.l 24.8 34.3 35.a 37.3 46.0 46.8 47.4 J.zusa•• 1971 5.s 8.3 . 13.7 15.0 15.7 16.} 24.l 25.0 31.6 35.9 ;6.2 36.5 3~-7 37.0 37-2 1972 6.4 8.0 · 10.1 11.4 . 12.7 13.9 14.8 22.2 27-5 33.0 33.2 33.5 33.7 :,4.0 34.3 19'/3 7.s 12.5 15.6 17.1 21.7 27.) 32.1 35.1 37.2 35.0 3B.3 ;e.6 !-C.9 39,2 39.3 1974 6.ey 7.s 11.7 14.6 15.3 16.2 18.0 24.2 28.8 3a.2 J8.5 38.8 )9.2 39.5 39.7 3urba."1.r.-:r~••• 1970 0.5 5.5 8.2 10.7 lJ.5 14.0 17.5 18.0 18.2 18.; 18.; 18.4 1e.5 1s.5 p71C I 9.4 10.4 10.6 10.8•-~ 12.4 12.e. }.5.3 15,.7 16.8 17.0 17.l. 17.1 17.2 17.2 17.2 l9':2c '.'--'~ f..9 7.1 R.7 4.? 9.6 l?.O 1;.1 14.8 15.0 15.1 l~.1 l<;,,? w l':'73c 15.l 19.l 22.6 23.5 2.::>.6 23.4 29.5 30.4 53.7 5".6 ~-8 5s,.o 55.1 t~J 1;J "'I 197-.e 6.9 10.l 11.6 12.9 13.6 14.3 17.4 27.9 43,8 44.5 44.? 44.8 45,0 45,l 4).2 Garder. Crove~H!:SS• 1972 6.5 7.5 8.5 9.4 10.5 11.2 12.1 15.0 16.8 18.6 20.6 21.5 23.5 25.6 26.3 19:13 11.2 14 0 1 15.8 16,7 17.s 19,8 21.4 2;.1 26,l 31.3 ,.,,.3 35.8 40,5 41,3 42.0 1974 6.8 8.2 9.5 10.6 12.1 14,0 15,6 18.0 23,6 39.1 31.6 34.8 36.2 45.1 46.2 GlentR~c-~~••• 19700 6.2 6.5 6.8 7.4 • 10.; 10,6 10.9 16,5 20.4 20.7 20,B 20.8 20.9 20.9 21.0 l•.Pl -- ~ 10~;:,C 6.6-- ?.l-- 7.4-- --7.? 11.0 11.2-- 11.5-- 11.8 -- 14.8-- 15.0 15.1-- 15.1 -- 15.2 -- 15.2-- 15.2 -- 1973° 4.l 11.0 13,6 14,8 16.0 17,l 17.a 18.4 35.1 35.7 35.s 35.9 36.0 }6.1 !,6.2 197:+C Glendor~-CHESS• 19:12 6.8 8.3 9-• 10.3 11., 12,3 13.s 15.9 1e.7 23.3 23.9 24.6 25.4 45,l ..,;.5 197:; 1:;.8 17.5 20.0 21.9 25.2 25.8 20.8 29.5 36.0 46.7 48.2 5-3.0 co.a 61.2 62.0 1974 •-7 8.6 10.:; .11.5 1:;.7 15.4 17.7. 21.7" 27.1 }'4.6 ~a.5 44.3 47,9 • 48.13 43.8 Le:c.nox•• 1970 6.0 7.2 8.4 10.:; 15.6 19.0 22.:; 24,2 29.5 44.0 .... -44.? 45.1 45,4 -45.? 1971 8.9 12.l 15,2 17.; 19.2 21.8 24,7 26.4 ;7.? 39,2 39.5 39.a 40.l 40,4 40_7 1972 8.6 10.1 10.8 12.6 13.5 14.0 15.4 16.6 19.7 26.2 26,4 20.6 26.S 27.0 27.2 19/3 7,6 10.9 1:;.1 17.2 20.5 24.2 3l.,8 :;o.:; 46.9 '1?,B 4l:l,O 48,2 -48.4 48.6 48.? 1974 9.2 11,4 14,0 16.l 19.3 20.9 27.1 28,9 35.5 40.4 40.7 41.0 -'tl,4 -'tl.7 42.0 I.one !e~ch-NJ.SN••• 1970c . 6.1 7.8 8.9 9.3 9.8 10.e- 11.3 14.2-- 15.; 15.5 ~5-6- 15.6 15.7 15.7 15.7 i6Z;e -6.0 --7.3 --7.5 8.3-- -9.7 9.9 10.1- 10.4 12.3-- 12.6 12.6 12.6- 1?.?-- 12.7 12.?- 197~c 13.6 14.1 15.6 16.l 23.1 · 2:;.5 24.0 26.6 27.1 27.) 2?.3 27,4 27.4 27.5 27.5 197-+C 6.7 11.7 14.7 16.0 18.7 19.:; 19.9 28.4 44.2 44.9 45,0 45,l 45,3 45.4 45,4 • t.oa .l.r.p:!:'lea•• l')'/0 G.~ ·7-9 9-~ 13.4 15.8 19.5 ?3.;! >5.7 31.5 35.0 42,5 42.8 4~.,. 11 ;.s 4},8 l•J/lc 9.11. ,,7.7 ,.~.") 10...,..,c l:?.l 15.7 17.5 19.2 20.4 24.2 31.1 42,6 4(,., 46.'3 1.7.0 4'/.!) b.l 0.5 '),0 l).•.i 10.7 1:-',0 111 -? 1r,.o n.1 :;~.:? 53.5 30.7 !/' ,() !,U.,2 }'-1-.'l 19f3¢. 11.5 1).2 15.5 1s.9 .::;.6 25.6 31.4 )6.7 £1-l.9 t:.2,8 4}.2 4~-5 -~-8 'l-11,:t ..... )'),"IIC a.,, 10.) 14,? lf.. 5 21.8 ;,;,.5 23.2 28.4 31.5 J?.6 )7.8 }8.2 !S,4 ~13.? !~-"i ARB 1975 • •
TABLE t:::I-7 (~•mt•~)
lQ. l:2 .lQ 40 .:;g_ 60 80 Loa k:geles-NASN••• - 22 ~ '.l.l. ~ Xl 1§. Xi. ~ 1970c 10.9 13.4 lJ,9 14.5 15.0 15.? 16.2 i~.9 . 40.2 40,3 4-0,4 4,.6 1971c 1,5 11.O 13.4 39.6 41).5 '-0.'3 14.l ·14.5 11~.8 15.1 15.7 21.s 21.9 22.0 22.l 22.1 22.2 ;,2.2 l<:'72e. 6,9 7,2 7,5 7,9 9,0 10.7 12.4 1Q73 11.4 13.0 12.9 14.0 14.2 14.3 14.3 14.4. 14.4- 14. 5 16.6 17.3 17.7 18.0 18.4 19.0 23.6 24.0 24.l . 24.l 2.:i.2 ;.,,. 2 l~'Z-'lc G.l . ~'-6 23.9 lC'.G 11.3 1:'.0 l'.;>.3 ;-o.s ??.2 "??,.? 119,6 '.:,0,3 :,'J,11 :,_:;,., ~--·.? r:,-;.: Ontario-!:..\.Ss•,c...,, • • 10.5 11.2 12,7 ic/:l: -- lJ.J-- 14,0 l?.3 17.9 18.5 21.9 22.2 22.3 22.3 22.4 2?,4 2;-,4 l•'"':?" 1i.r -G,O- (,,2 C,,P,------1n7,;C .., 7,1· 7,J 7,G 8,5-- e.s-- 8.7 8,7 -F,,7- 8, 7 ,:,_,_ 7 11.0 11.5 15.1 16,5 19"/4c ------20.1-- 20.6 21.0 25.7 26.l 26,3 26.3 26.4 c'C,4 c'6. 5 ~w.;:, Passd~r19• • F 171 5,4 7,9 ll.4 11,8 12.2 12.6 lG.4 21.7 24,3 34,0 ;Ji,2 ' 1cr:--- ~,.,, f,. 5 E\,O ,0,.7 J4,5 ?r,7 .,~.-.. - 5;..1 1,_,·~,; ')."- 10,5 11.9 13.2 ?'.°,.II ?7,5 ?7,7 ?7.9 2':.. l ;..f!,. 3 ;.,,;.<- 7.0 ll. 5 13.3 19,1 ?0,5 25.c 27.6 31.9 19;,-.. ~.o G.2 30.7 ~!3.1 ~'3.1i y:,.7 ~i:..'.1 ~;.;- Y:,j 9,3 12.1 l.',,6 14,7 15.9 19.2 24,l 30.3 j'J,5 38,B 3;_,'j ~:., ~:.1- Pae!'ljer.'1.-SAS~••• l·'··•'-, 14 -~ l~.2 15.<) 18.<) 21.11 : <1;1e 20.7 :>?,l 2:':'.8 ?3.1 28,11 2fl,S ?8.~ ?~J, ?~., ?"~. 7 l ,, .. ">c -6.6- 7,1------':/~-~ 7.5 8.9 10.8 13,6 14,1 23,9 24,8-- 25,3-- 2).4 .2;,.5-- C;'.'1 ~·_.?-- :·~-7-- 1~.9 lU.'.) l'/, l 17,7 ;::11,[c i ,.. :~.1 O 16.3 l').O .20.2 111.3 Ill.') 11?.0 11;•, 1 Ii?,°!: 1;;,_,1 ,.;.. ~ ~------Ret::ed.1•.•• 1,1•.·•,) ~-8 <\,ll 9.0 <),ti 9 • .9 Fl'?l l?.8 13.~ 15.8 1(,.6 ??,?. ?7,4 27,S · ';:7.6 <='i.e •-7 ... 6,0 7.1 7,6 8,2 9.1 12,0 17,l 22.l ?.4,/.1. 1-1--,,.. 5~.':) y1.l v..; ~ .r, ~ f.'.- ._ 7.1 10.3 11.8 · 15,? 111,3 lG,4 17.,~ :'Ll !'),') 3').3 ;;;.~ /;~,.~-·. :, l --.'.'5 ?,n 1').0 :'l.~ !,',•.:· '·" ?3.~ ?7.(1 ;'7,? 3(). t ,~.5 l1",,l 1,r,.P, 119. l 4 1,5 '•'}.3 C/,. l ',,' .', !.•_l",'-'1. s.o lQ,ll 12.G 14d .. I l'/, l 21.:;, 2.',.!, <.''.:,,l 2'/,9 ~/).? YJ,<;, 3'..', e IP,,!_ ,..,. ~ ,',.'., N .i,. Ri. V'\!" J i~r-~:,\S~• • • l-J/,..1 -11,IJ 11 ,') l:',3 12,(1 Vi,6 l'),() •• C I 16.1 l 7, 3 l7.f'I 1'). ~ l '}.I; l ') .,~ ,l'l,':> • -,. ✓ o-1e 1'l • ~ 1 .1.1 l.' l.4 9.7 9,S 10.0 11.6 11.? 11.9 11.9 11.9 1?..0 lt'.~ .i,;:.'J 1::.'J 11?2: 7.5 8.0 8,5 12.'., 1;.1 1;.c, 1'/,C, 11.l,l 21.2 21.J ;:,1.r, ;--, .7 1,1..J'' 21.~ ?1.? ?1.7 l')74e
S!\t\ 1'<'t·1,:ll'\1lno-NAS?t••• S.8 9.1 9.4 12.1 17.0 1'/ ,6 20.4 21.0 2'.>,9 2',.2 ;:,r:,.~ ~r,. ~ ;••,.1-1 ;-.. ,, ;,:,. '.:, t~~~-= ------1l1~2.: 6,4 -- 8.2 -- -- 1;.4------1,v, j<' 7.7 8.5 8.8 9.J 9.9 17.7 ie.o 18.0 lC.l l~.l 1:: .? c;,.z. l&,O l(;,a l?.f, lf'.,3 Fl,') 21-1.1 ;,c,,7 f/,,? F;r,1 r,<,.? .-,:,.';. 197.:+C G3.9 r,s·.'1 ,.;. ~ 10.8 13.0 13.7 17,J 18.0 18,7 19,4 }'•.6 3;,.3 35-6 3;,.7 ;i).t~ ?,~.. '.) ;.,-. 3 ~;,.'.1 SantA ~o~ic~-cH:ESS•· l~l'.'_>,J 6.0 7.0 7,6 8,3 0.0 f).7 11.2 13,7 1r.• 1 1 PJ, )9.1'.i ;:>~ ..., 19-;,3c ~?./3. ;:,t. 3 ;:?.'1.. 10.9 1 15,0 16.9 19.0 20.5 22,l 23.6 27,4 3'/,2 ~·1.2 4'j ,'l '> l, ') 19':'·~c 3'/.'l ?,.:.': ?,? ti• 10.5 11.7 13.1 15.1 17.2 21,l 2G.O 37,5 38,1 ?,B.'j 3':.,') )!·. !, ;.r.• ~ '1'01•1":'l!l~••-!i,~~· •• 19·70 8,6 9.0 9-2 9.4 9.8 10.2 10.7 11,l , •l"' C l'.id l~.~ l~.& l~.G '-'.i, 'I 1 '·· ., 1 ;.7 io7zc t•.4------5.9 9.8 10.2 10,4 10.6 . 1::.• 2 14,l / 1-i·· ~e 10.8 13.y 111.1 14.l 11•• ~ lh 0 1,. -~ 10.1 13;.6 111,'• 111 .') ,19',3 21.0 ;>;>,3 197,:.e Vi-? 32.5 ~?.') 3?,9 ! ~-0 3~.l ~3-~ 3~-~ 9.9 10,2 10.6 11.2 , 15,5 16,2 24.0 24,8 29,0 29.4 29, 5 29,5 2').f, 'i::;. 7 2',:, 'l T~0U:l!lt:,t 011ko-CltESS• lC\..,~ 4.9 16!,)- 5,9 6.7 7,6 8.8 9.s 11.5 13.3 15,6 20.l 20.1~ 21),8 <,1••1 2,••,: ,,.-1.~ 7,4 10.8 13.0 15,l 17,2 19,4 21.9 24,2 2,3.2 1,f,,2 ,1~\:,:,:- ;3.4 35,l 11~.;:; t! ,3 -.:.~ (,,2 7,8
TABLE III- 8 SUl'MARY OF ACHEX SULFATE AEROSOL CONCENTRATIONS AVERAGE OVER SAMPLE PERIODS JULY-NOVEMBER 1972 AND 1973
(Micrograms Per Cubic Meter) Site 24-Hour 2-Hour A. West Coastal Dominguez Hills 3.64 19.66 (l.51-50.3) * Harbor Freeway 5.80 B. Central *Pasadena 6.43 4.11 (2.9-11) (0.46-9.42) West Covina 20.4 21.4 (6.48-32. l) (3.38-69.5) C. Eastern Pomona 10.3 32.5 (4.4-19) (22.33-51.8) Riverside/Rubidoux 8.3 17 .0 (l.96-21.2) (0.99-48.2)
*1972 Only Nt.nnber in parenthesis refer to range
TABLE III- 9 SUMMARY OF ARB SULFATE AEROSOL CONCENTRATIONS RANGE OF 2-HOUR SAMPLES JULY-OCTOBER 1973 &1974
(Micrograms Per Cubic Meter) 1973* 1974 Site 2-Hour Samoles 2-Hour Samnles Los Angeles 5.0 - 58.4 3.4 - 60.2 Riverside 4.1 - 44.8 1.2 - 43.5 Anaheim 4.5 - 42.8 Pomona 7.2 - 75.9 1.8 - 58.4 El Monte 12.4 - 58.2
* Questionable Validity
ARB l975 -25-
I \ I • \ L___ - I \ \ I VENTURA CO. \ LOS ANGELES CO. L_L/ ------RESEDA (15. 9) o CRESTLINE 0 18.7 14. 2 , __Ji 16.9 10.9 BURBANK o· 10 4 PASADENA GLENDORA / o~- 0 ·o 15b8AZUSA .o 1S. 7(25. 4) THOUSAND GLENDALE L 13.4 ;' (33 O) FONTANA - SAN 1.,.,. OAKS o OS ANGELES WEST ~DVINA . o UPLAND (28.8)o RIAtTo o BERNARDINO WEST 11. 9 LOS ANGELES 15.3 14.2 ONT~R_JO o 10.5(21L,2)__ (34.1) o(23.4) ~_..., 0 ,,J °CHINO j ---,___ REDLANDS 0 SANTA MONICA ·-· , (30.4) r--· . 11.41 ----1 --~2.4 li,8 : ~. J' . RIVERSIDE LENNb'X r1 " ;· I ~~TORR~CE 12.5 ''( HIVEHSIOECO. N I O'I I 11.8 LQNG0 14.ol / o ANAHEIM '\ BEACH , GARDEN ~..Jr!?-.... ) GROVE c\3.0 '\. . 0 ··= SANTA ANA. ORANGE CO ·, 11.7 · L ...... -=-- '), .I /g ¥/Ltl
I• - Numerical exponents represent months of t---,__ missing data. r--·"' -- -San Bernardino Zone data in parens / . .,__ - I
FIGURE III-1 HIGHEST ANNUAL AVERAGE SULFATE CONCENTRATIONS (µg/m3) SOUTH COAST AIR BASIN, 1972-1974 ARB-1976 • \ \ \ i___ -- \ LL_I ____ _ wr~ca~ LOS ANGELES CO. RESEDA -; 0 55.3 • 69.5 BURBANK o 71.5 / 84. 6 ___J PASADENA .GLENDORA o~- 37 .9o 0 56 o'i o THOUSAND GLENDALE 48.4 SAN BERNARDINO ., OAKS AZUSA ' ~. 65. 32 AN o I 5 0 Los · GELES WEST62 COVINA 5 ONTARIOJ 029. l ----~---,• ·---, 72.2 • r· J 31.2 0 SANTA MONICA 4 56.3 ,r ('' o RIVERSIDE 53 3 r-.- -~. ,....1 LENN8x • ~I · " .'(I l?/VERS/OE CO. I / 65 8 . ' .....N> TORRANCE I ·===t 0 45.3 { o ANAHEIM \ 0 , ' 33.0 LONG /GARDEN 55. 7 \.. 'BEACH ) GROVE o . o ORANGE CO. 1' SANTA ANA ...::.;.;,;.--"--- \.-..--._ 60.9 ')
I I II JI/Ill I ,,t---.__.,__ -Numerical exponents represent months of missing data r I
FIGURE I II-2 HIGHEST 24-HOUR SULFATE CONCENTRATIONS (µg/m3) SOUTH COAST AIR BASIN, 1972-1974 ARB 197/i
•
• \ I ' ' ,__ ---- \ \ I I VENTURAC/J.~ LOS ANGELES CO. L_L______
•I _;___.J / 58.2 I EL t~NTE 0 o LOS ANGELES WEST COVINA ·o i POMONJ ~ 60.2 69.5 ------.' ,.__. ---,1.· ,,S75.9 j 48.i • r-• · RIVERSIDE 50.3 r-·--.i___ ....J' 0 RIVERS/OE CO. I N DOMINGUEX / ) "-~' CX> I ~ HILLS { o ANAHEIM \ :, , \ / 42.8 \__ ·= ."'-. ) ORANGE CO. 1\ - ., -----.... ) :,,. ;' II II/Ill ./
Concentrations are not representative of entire .~l- - ,__ .:. -'--- 1972-1974 period r I
FIGURE III-3 HIGHEST 2-HOUR SULFATE CONCENTRATIONS (µg/m3) ARB-1976 SOUTH COAST AIR BASIN, 1972-1974
IV. COMPARISONS OF AMBIENT SULFATE CONCENTRATION DATA To illustrate similarities in recent ambient sulfate data monitored by some of the various agencies, comparisons of concentrations sampled at locations in close proximity are provided. A. Yearly Average Comparison 1. Los Angeles Zone-NASN The monitoring of ambient sulfate concentrations in downtown Los Angeles by the Los Angeles Zone and the NASN is the longest parallel study of sulfate concentrations at the same site. A comparison of annual average concentrations from 1965 to 1974 is shown in Figure IV-1. The trend of sulfate concentrations measured by NASN is fairly constant from 1966 to 1973, but data by the Los Angeles Zone shows an abrupt jump in concentra tion from 1968 to 1969. The cause of this change has not been definitely determined, but may possibly be due to a change in the filters used by the Los Angeles Zone. Apart from the 1968-1969 discrepancy, another factor which may be significant in accounting for the differences in the annual averages is the fact that the two agencies have different sampling schedules. The Los Angeles Zone samples every six days,,generally taking 60 to 80 24-hour samples a year, while NASN samples approximately every two weeks, collecting about 25 to 30 samples a year. Since the larger number of samples would give a more accurate statistical estimate of the annual average concentration, the annual average concentrations wliicli-were detenmneabythe Los Angeles Zone after 1969 may be more reliable than those determined by the NASN, assuming any systematic'errors are insignificant. B. Monthly Average Comparisons 1. NASN-CHESS Anaheim is the only location common to the NASN and CHESS networks. The NASN monitoring site is located about two miles northeast of the CHESS site. A comparison of the monthly average concentrations, using data for the same days in 1974, is shown in Figure IV-2. Although NASN concentrations are consistently higher than CHESS concentrations, the differences between the two are slight. 2. Los Angeles-CHESS-LACS A comparison of ambient sulfate concentrations on a monthly average basis, using 1974 data collected on the same days from West Los Angeles (LA _Zone), Santa Monica (CHESS) and. the Sa.n Diego
-29- Freeway (LACS), is shown in Figure IV-3. The San Diego Freeway site and West Los Angeles station are about three and four miles east of the Santa Monica (CHESS) site, respectively. Monthly averages of concentrations on the same days collected during 1974 for Azusa (LA Zone), Glendora (CHESS), and West Covina (CHESS) are illustrated in Figure IV-4. Glendora is located about two miles east and West Covina is about six miles south of the Azusa site. Both of the figures show that the various agencies obtained fairly similar sulfate concentrations in the same geographical areas during 1974. C. 24-Hour Average Comparison 1. Los Angeles Zone-NASN A comparison of 24-Hour concentrations monitored by the Los Angeles Zone and NASN at the same location and on the same days were made for data collected from 1972 to 1974. The common locations were downtown Los Angeles and Pasadena; Figures IV-5 and IV-6 correlate the data which indicate that there is no consistent relationship between sulfate concentrations collected by the two agencies.
-30- 25 ~ M ...__E 0--0 Los Angeles Zone en ::L t:r--6. National Air Surveillance Network ~
C: 0 20 ·~...... "'... C: a, u C: u0 15 ....a, I w ....."' ~ ~ I ::, V) a, 10 en
"'...a, > <(
~ ::, 5 "'C: C: <(
1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Year
- #~ FIGURE IV-1 ·~ COMPARISON OF ANNUAL TRENDS AT DOWNTOWN LOS ANGELES
ARB 1976
0-----0 tlational Air Surveillance Network 25 1::.--8 Community Health and Environmental "'E i Surveillance Network ---"':,_. C: 0 -~..., 20 ...,"'s... C: Q) u C u0 Q) wI ..., 15 N ....."' I ~ :, VI Q) O> s... "'Q) > 10 < >, ~ .<::..., C: ::0 5
an May Month FIGURE IV-2 . COMPARISON OF SULFATE CONCENTRATIONS Bf NASN AND CHESS AT ANAHEIM USING SAME SAMPL!llG DAYS, 1974
ARB-1976
0----0 West Los Angeles (L.A. Zone) t:, t:, Santa Monica (CHESS) 25 r 0--0 San Diego Freeway site (L.A. Catalyst Study) I M ..-...__E O> :a,. ~ ,:: 20 ·~0 .µ,.. .µ"' . ,:: QIu ,:: 0 15 I u w QI w .µ I ...."' ~ ::, V'>
"'O> 10 "',.. "'> "">,
'.c:.µ ,:: ~ 5
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month I · FIGURE IV-3/ COMPARISON OF SULFATE CONCENTRATIONS BY L.A. ZONE, CHESS AND L.A. CATALYST STUDY IN APPROXIMATELY SAME AREA USING SAME SAMPLING DAYS, 1974 .
ARB-1976
•
0--{) Azusa (L.A. Zone)
~ 6 t,,. West Covina (CHESS) 251 ....."'E 0, ::,.. 0----0 Glendora (CHESS) ~ C ·~0 +> 20 s..."' +> C Q) u C 0 '-' Q) +> ...."' 15 ~ I :, .,..w V) Q) I 0, s... Q)"' > , ~.,:; +> C ~ 5
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec ~onth FIGU-R(iV-4 COMPARISON OF L.A. ZONE AND CHESS IN APPROXIMATELY SAME AREA USING SAME SAMPLING DAYS, 1974
ARB-1976 ' 40
35 ~ M E
---"'::i. ~
1/1 c:: 30 ·~...,0 ...,.."' C: 13 Samples Q.> u c:: 25 u0 ...,Q.> '+-"' ~ ::, V).. 20 ::, 0 :x: ....I N 15 z V) ci:z
10
0
5
0 0 LA Zone - 24-Hour Sulfate Concentration (~g/m3) FIGURE IV-5 COMPARISON OF SULFATE CONCENTRATIONS AT DOWNTOWN LOS ANGELES BY NASN &LA ZONE (1972-1974)
ARB 1976 -35-
40
35
~ M E C, ----::1. 30 -V, C: 0 ·~...., 14 Samples ....,"',._ C: QJ u 25 C 0 u ....,QJ 4-"' ~ 20 ::, (/) ,._ ::, 0 :x: ...I N 15 0 z: (/) 0 cl; z: 0 10 0
5
0 5 10 15 20 25 0 LA ZONE - 24-Hour Sulfate Concentration (~g/m3) FIGURE IV-6 COMPARISON OF SULFATE CONCENTRATIONS AT PASADENA BY NASN &LA ZONE (1972-1974)
ARB 1976 -36-
V. CHARACTERISTICS OF SULFATES IN THE ATMOSPHERE Although the formation of sulfates in the ambient air is not yet fully understood, several characteristics of sulfate aerosol have been determined. A. Total Aerosol Breakdown and Light Scattering Contribution The most abundant chemical species in the aerosol over the South Coast Air Basin are sulfates, nitrates and organic compounds. From the analyses of 24-hour particulate samples collected in the Basin, sulfates have been shown to constitute from five to 40 percent of the total aerosol mass. The percentage of sulfate in total aerosol also exhibits a seasonal variation; the fraction of sulfate in the aerosol is generally greatest in the summer months, as illustrated in Figure V-1, for data collected by the Los Angeles Zone from 1972 to 1974. On an annual basis, sulfate concentrations account for about 10 percent of the total aerosol mass, as shown in Table V-1. The geographical distribution of these components is shown in Figure V-2. In the ACHEX study, the concentrations of sulfates, nitrates, organics and total suspended particulates were empirically related to the quantity bscat• which is a measure of the amount of light scattering. The equation for this quantity, called the aerosol light scattering coefficient, is 2 bscatxlo4 (m-1)= -1.l+0.074 (so4)+{0.025+0.049 µ )(NOj) +0.025 (organics)+0.025(mass-(S04+N03+organics)) where concentrations are expressed in µg/m 3, andµ is the fractional relative humidity. The relationship bscat has associated with it a standard error of estimate of 0.9xlo-4iii-1, corresponding to a visual range of 10 miles. The relative error of this relationship is proportionately less for higher values of bscat (or for lower values of visual range, since visual range is inversely proportional to bscatl• The geographical distribution of bscat is shown in Figure V-3. · On the average, sulfates are shown to be responsible for about 20 percent of the visibility reduction in the Basin. B. Particle Size and Size Distribution The particle size distribution is an important characteristic of sulfate aerosol. The size distributions at four sites studied by ACHEX are shown in Figure V-4. At all locations, sulfate particles generally had mass median diameters in the submicron size range (~1.0 µm) and were smaller than that of nitrate particles, as indicated in Table V-2. Preliminary studies by the Crocker Nuclear Laboratory show that most ___ of theparticufafe sulfifr-is in th·e-form ·of' sulfate-andis usually -Tn the size range of 0.1 to -5 µm, as- shown in Figure V-5.
-37- C. Dfurnal Varfation The ARB's aerosol monitoring in the summer of 1974 determined the most probable peak times for two-hour sulfate loadings. These data are listed in Table V-3, along with the mean concentrations during that period. The diurnal variations of sulfate concentrations, shown in Figure V-6, indicate that concentrations in the Los Angeles Basin peak at about noon, with some variability. D. Seasonal Variation Analyses of monthly average sulfate concentrations monitored by the Los Angeles Zone from 197D to 1974 indicate that levels have generally been highest during the suTT111er months of June through August and lowest during the winter months of November through February. A composite of monthly average concentrations from 1966 to 1974 for downtown Los Angeles, Lennox, West Los Angeles and Reseda, shown in Figure V-7, illustrates the seasonal variation. Although the sulfate measurements made by the San Bernardino Zone are questionable, the data does provide an indication of the periods of the year when concentrations are highest and lowest. As shown in Figure V-8, the data from 1968 to 1974 indicate that sulfate levels were generally highest during the period June to August and lowest during the period December to February, It should be noted that there are fluctuations in the seasonal trends from year to year, but over the past several years the above trends have generally been observed. E. Trend of Ambient Sulfate Concentrations Of the programs and studies which are monitoring ambient sulfate concentrations in the South Coast Air Basin, only the Los Angeles Zone and EPA's National Air Surveillance Network (NASN) have suf ficient acceptable data to provide annual average sulfate concentra tions for the past eight to nine years. The sulfate concentrations measured by the San Bernardino Zone can also be used to some degree in showing the trends, although they are questionable (See page 2). A comparison of the trends of the annual average concentrations by these agencies is shown in Figure V-9, Annual average data by the Los Angeles Zone are a composite of data from Los Angeles, West Los Angeles, and Lennox; the San Bernardino Zone data are a composite from San Bernardino, Rialto, Redlands, Ontario and Chino; NASN data are from Los Angeles; and CHESS data are a composite from Anaheim, Garden Grove, Santa Monica and Thousand Oaks. These sites were selected because no major interruptions occur in the data record. The data from CHESS are available for the entire years of 1973 and 1974. In Figure V-9, the data for the Los Angeles and San Bernardino Zones show similar trends from 1966 to 1969, but thereafter, they are quite different. The NASN data did not exhibit the same trend shown by the Los Angeles and San Bernardino Zone data from 1966 to 1969. From 1973 to 1974, NASN and the San Bernardino Zone data indicate an increase in sulfate levels, while the Los Angeles Zone and CHESS data indicate a decrease. Although some of the discrepancies in these results can be accounted for by meteorological variations, regional emissions and analytical effects, the fact that these agencies have different sampling schedules (number of days sampled per year and their distribution) may also be responsible for the apparent disparity in the sulfate trends, especially between Los Angeles Zone and NASN data. F. Relationship Between Concentrations for Different Averaging Times Analyses of sulfate concentrations, as well as data for other pollutants, indicate that air quality measurements tend to fit a general mathematical model. In an EPA publicationlO, analytical studies showed that statistical parameters for one averaging time can be related to those of another averaging time. To illustrate this characteristic, log-log graphical plots of maximum sulfate con centrations versus averaging time for Los Angeles, Azusa, and Riverside are shown in Figure V-10. The leveling off of maximum concentrations at short averaging times indicates that sulfate concentrations for these time intervals will probably not be significantly higher than the 24-hour level. Use of figures such as these aid in predicting sulfate concentrations for different averaging periods.
-39-
•
TABLE .V-1.HI-VOL PARTICULATE COMPOSITION: CHARACTERIZATION FOR YEARS 1967-1973
Concentrations in µg/m 3
Location Total Suspended Particulates ,,. Benzene Solubles Pb s04 NOj 4 AGM AAA
,. .••• 1 • ' ; . --
1. Lennox 135 145 6. 7 l J. 2 7 ,4 N/A N/A I4.6,) (9.1') (5.1')
2, West LA 85 90 3.0 9.3 6.8 N/A N/A I3.3,J (lo.3,l (7 ,6')
3. Long Beach 95 105 2. 3 11.2 5.6 1. 5 10.2 12.2,1 (10.7%) (5.JS) (US) (9.7S) ,. _____ . "-••--· ,,. __
4. Downtown 130 140 4.1 14.3 11. 6 1.4 14.0 LA (2.9S) (1 O. 2S) (8.3S) (1.0S) (10.0,)
5, Pasadena 110 120 3.6 12,7 11.4 1.2 13.8 I .i,. (3.0S) (10.5S) (9.5S) (1 .OS) (ll.5S) 0 I 6, Anaheim 95 105 2.8 8,7 6. 5 o.8 -- (2.7S) (8.JS) (6.2S) (10.8')
7. Reseda 130 140 4. 3 12.9 8.4 1.4 16.0 (3.1') (9 .2,1 (6.0S) 11.0,1 ( 11. 4S) ' !:°•• L. ··- •.•... ~ ·-• • ,., L. • 8. Azusa 150 160 7' 0 )5-2[) 17 .7 ------. 1,9'\ 9.51 (11.1') 9, Ontario 110 120 1. 9 10.2 10.a 9.4 (l.6S) (9.SS) (9.o,i 1.0(0.8S " 17 .81\ 10, s'" 115 125 2.0 12.6 13. 1 l.O 11. 3 Bernardino (l.6S) (10.1') (10.5S) I .8s) (9.0S) 11. Riverside 140 150 1.8 11. 7 15. 1 1.5 (1.2') (7.8') (10.1" 11.0,, };·~•r\ u ••••••••• -- -· .. ' •-·•
12, Chino 180 195 1.95 19.5 17.6 (1 .0,) 110.0,1 (9,0S) ·--- Jo.7[)5. 51
Note: Numbers in parens are percentages of total suspended particulate; AGM • Annual Geometric Mean AAM • Annual Arithmetic Mean
Source:...... ,Reference <.·: __:: '-~ . 9
TABLE V-2
MASS MEDIAN PARTICLE DIAMETER SOUTH COAST AIR BASIN, 1973a)
Nitrate Sulfate Samnlino Location ! .. ml (um l
Dominguez Hills Oct 4-5 1. 64 0.43 Oct 10-11 0.72 0.42
West Covina July 23-24 1. 13 0.34 July 26b) 0.62 < 0.22
Pomona Aug 16-17 0.68 0.39
Rubidoux Sept 5-6 0.33 0.33 Sept 18-19 0.34 o.43
aExcept as noted based on 24-hour average size distributions obtained with the 5-stage Lundgren Impactor. b13-hour average, 0500-1800 hours.
Source: Reference l
-41-
TABLE. V-3
MOST PROBABLE SULFATE PEAK TIMES July - October, 1974 Site Time (PDT)
El Monte 10-1200 Los Angeles 12-1400 Pomona 14-1600 Riverside 06-0800
!"I J,J '" K f 'f"t1 I_ l1
MEAN 2-HOUR SULFATE LOADINGS July - October,· 1~74 1,ean Site Loadings
El Monte 32.3 • Los Angeles 24.2 Pomona 23.6 Riverside 20.4
-42- ARB-1975 , ,
25
II 0 "-TIO..V1 V1 I- Composite of Data at: 4- 0 Azusa C/1 20 Los Angeles
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month FIGURE V-1 MONTHLY TREND OF THE SULFATE PERCENTAGE OF TOTAL SUSPENDED PARTICULATE MATTER, 1972-1974 LOS ANGELES BASIN
ARB 1976 , LOS ANGELES~- POMONA 181 135 ~WEST C · ~ ~195
I .J>, .J>, I
DOMINGUEZ HILLS N () 118 ()ANAHEIM ~ 120 1--r·- . ~ .rf:jr:::--,~ *· rzl NITRATES SCALE IN MILES ~ SULFATES 0 5 10 llllJ ORGANICS 0 OTHER
FIGURE V-2 : I GEOGRAPHICAL DISTRIBUTION OF AEROSOL MASS CONCENTRATION (rgtm3} AND ESTIMATED .· BREAKDOWN BY COMPONENT. (Average of Two-hour Aerosol Samples at Mobile Van and Satellite Stations.} Asterisk indicates Carbon Measured for Less Than 2/3 of Samples at that Location. Source: Reference 1
_, * - LOS ANGELES ~- 4.2 II ~WEST• C 0 5.9 _,,.I <.11 I
~ DOMINGUEZ HILLS ~ 3.5 ~-ANAHEIM I r I ~ (/:)=, ~·· 82] NITRATES SCALE IN MILES l;;l SULFATES 0 S 10 !!!Jl ORGANICS D OTHER
FIGURE V-3 , . GEOGRAPHICAL DISTRIBUTION OF AEROSOL LIGHT SCATTERING COEFFICIENT (lO-4m-l) AND.ESTIMATED BREAKDOWN BY COMPONENT. {Average of Two-Hour Aerosol Samples at Mobile Van and Satellite Stations.) Asterisk indicates Carbon or bscat Measured for Less Than 2/3 of Samples at That Location. Source: Reference l
20 WEST COVINA July 23-24
20
10 POMONA August 16-17 M E m ---ci
n. 0 m 0 --'
~ RUBIDOUX :E"' <> September 5-6 5
2
RUBIDOUX September 18-19
2
10 Particle Diameter, Op -- Microns
FIGURE V-4 24-HOUR AVERAGE SIZE DISTRIBUTIONS FOR SULFATE AT RECEPTOR SITES, 1973
Source: Reference l
-46-
~ ~ v,'\ "'"cs ci ----- C) "'" w ~ N -.J -VJ ~ w ..J u "' I- o°' -0:: "' c,: 0.. 0 0 0 0 LO VJ ~ I => ID ... > VJ "' "' 0:: ~ w w r;E 0:: > => ..J -~ t!) c;; 0 cs--~ VJ u..- 0 0:: w c,: u.. 0 ~ Iz- . w u ~ 0:: (J w 0.. -J- -V) N a, C: "a, s.. a, ....a, ~ 0:: ~ a, s.. :::> "::, V) 0 VJ 0 0 0 0 0 0 IO IO ... ""'" "' "' ~ ~ -47- ... ., ' 45 I- -- Los Angeles 40 f- --- Riverside ••-• El Monte __,,. ,,,..•--•-----•--·, ... 35 1- . ., , ...... Pomona , ., .,•, .,,.. ., • • _.,,. _.,,. '·' 30 f- ..,,. ·, ..,,. _.,,. ., __1_1_1_1___ ·········· ·,.' ~ 25 1- I_,_...... --:-...... :__ ••••••.... 0 ...... M _,-::_,_ -- e ....,...... ···•·· ,,,,,....-~--··· ...... -- ... 0,, ,,,,,,,,,,,,,•·..... -----""'--...... - ----;a.. ... ~ ....Cl) 20 t- ---••,,,,,••...... ------I .,.:.---·------. ~""•• .... +> ...."' •• ------~ co ::, I V, 15 t- 10 1- 5 I- I -1 -1 -1 -1 6-8' 8-10 10-12 12-14 14-16 16-18 Time (PDT) FIGURE V-6 ( MEAi! SULFATE DILIRN.~L VARIATIONS SUMMER 1974 ARB-1975 • ... • • • ~ M E 01 ----:i. ~ 25 C: -~...,0 ...,s.."' C: QJ u 20 C: Composite of Data at: u0 Los Angel es ...,QJ West Los Angeles Lennox '+-"' ~ Reseda ::, 15 r V, - 0 I QJ ,,. 01 0 I "'s.. '° QJ □ > <( 10 0 >. ~ .c..., C: 0 0 ::E □ 5 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month FIGURE V-7 MONTHLY TREND OF SULFATE CONCENTRATIONS, 1966-1974 LOS ANGELES COUNTY ARB 1976 • • 25 Composite of Data at: San Bernardino Redlands -- .. , - ---•-'·-·' M Rialto :Itr~~:~--~~:-=-• --~-~:~ ·: i·±-:=·' ~-:-.' -E 20 Fontana Ontario ·--"'- ~ C _; j ' 0 ·~,..., ;·,'". t----,----:-,-----,---- ,...,"'S- r•-•-;~,-•- .,,.-'·• C 15 Q) :-;t; t.[Ef~\t~:~:~~= :~ · u ' ~- t -.. ' ·~·' - C 0 I u u, ,%1i~~!/1:~ 0 ,...,"' •,L•'-•·" I .._ "' - -~_:_~1-• ~ => 10 "L-~:- V') . ::;- ~ C"' 0 "' ----, - V')"' !~J,f \~f~llf,t~[l~::. . -,---- ·--• 5 ... -•-- ·- - ~i ~;_-?-?~~-~~~:-~~-r~:-}~~~~ /:,::-.:l •-·· ------·-· - -· . ...... ·- •---. -~ .,_. I I I I.,,.J{I:':ffiI~,fE:At... •r:•• ..•~h;,. ,..,.,.,,,,., •.,.._I.. . •-'-"'' . ·" ....-. ---·-"""·. 'L ..... , .·• -- , ., . iJ:mI,~!2}~c"J~ln~}V!~i:_= ·.~ ~:c",~;'.~: ~ilTii:;~ DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV Month 8 SULFATE SEASONAL TREND IN ~~~u~~u~ coAST AIR BASIN 1968-1974 SAN BERNARDINO COUNTY ARB-1976 • 0--0 Los Angeles Zone A ("'") br- - ~ San Bernardino Zone I -E NASN (Los Angeles) I ---"'::,._ 25 0---0 ~ I C: 0-----0 CHESS -~....,0 I ~ 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Year FIGURE V-9 SULFATE TRENDS IN THE SOUTH COAST AIR BASIN ARB 1976 • • • lODDJ ~1,11_. 8 I · 1. I !'··11 ~:•I•'· I··" .·1· .-± -~ "°"''"' m 7~ '.frl:_'jjjj; .1 H '!• rrW,, ;;\:.J••• lJ:::1::: 1•;:•1.::\;ttl~tt:11~::rnm~m:~Wd"'' 11 r HI "ii" 1•·1 l ·:+ J:.J :--iH :-l LL ::Jr ci:Tt"f gg iiE !m )\ll :~,iiH'ic• Pm ILI 1=.. : r\ i:: 1 •• ! ! ti•'•· i~:\:J,::i ~&ti .@ itfi ~ii\ i\'.: ~/ 4. ' 7J ,; .: t •x \: :1 :+++H· ::.:1H-1 :: !·: r .!--+-!++·-+++fl r: rnutn !]~:;JTl,EHTtIT11ttiifHlllllirn Uilll:: Ltq11H r1IBH ;;TI;; TT'C Cf C l -f • -,J ..,.- ; -; H" ::i1T •i•~ - EC'C C ;nsa, ii!. CCii!, S / !,C Tii. ;• c ffl1 itli Jffi """ • r, 0 •,1:•;• :·: 'I :::r-;-z •1 •:·•:: ,:, It :•:::·::::; .fJ.,~c:'i!j!~fc;,::::•:;;: :::,pp •;:.i::qq; 2 ·-·· :::·, ...:,...... ,,:.,-...... ·••· "' · .., ,::.. '" .,...... ·:.:: .. ~.;·,,:t;::,:· ::::::,: ::;: 1' ',, .,.,.,.,,:1:,·:::.::.::·:::. ,, " . ' T, ..,.,1 ·l I , I ..... ·•· ' :::i ,,. ': I· I: l.••-+j;(ln,.," •~"" ,c.• ,!q, ,1 .... ', 1•J·:1· . I : H/:::: :; t>:; :I:: J: ., .•... ;;;,, ~;: ½~:,: ~ ::i'. \ . ~ ~; ~~!~;;ii:'.::;::;[:::::: :::i::::::: M ;;···,~+ ti'" ;:;::.... :,: [{ :;::~~t: ':::;:: : i; .,:: ::. :1..·•·· ' ~:a: ·+··,,,.,,...... ,..,.;.+r~~Ht!•...,,.hlll••!i•·::, E 100 1.....,k ..,. ... vt:1.\ .. \.. ,. ,.1. .,. ::;: ... xhi ,... :,.t tL, ,'fl ,,;1,,,,,,,.1',. :r1;,H.1,,.,...... t ·; ""'- , l 1Ll ~' 0, 9 : !: . ; '10,;, ·i·l I I '. I. I: . i I: i ,, : : ::-1·: :i =·i -l_l_J-! 'I ~ l. _-r::-i i1t; • i 11 6~ "'' ~.w 2; : Lt~-'- : 'J.U'J-,i ' ' : : l :1' : I ,': C: =i-~t=-n-~-~~~ 1~1-; 1:;~:1 :~ :~r "r"!(: ;·.;_Lll+-tH :i~H!it0Ci!0fr-q til'ffit' I' ' i ~ '.(1;;:, I I 0 5 ,c:;\ , 01 0 ~::1H• ·•~••C;,~:+- .. .j.••.,, 1-;Jlfi; N ·~.µ : I; ?°/• ,... I'..,;; ...::r. , ., .. , , , •. if :;r,;:, UJ::f':'•••· ·.--,,,U"T' ~1•~.··.~-~.%f-;p.\·1·· i1t:12!1 U!JI -~-, i • : : : tLt I 4 :::,~-~-t-=~=_:1::_:"'L:_[Il·=.t=. · IT. LLL.L.1.I'~i~£ ·1:1 I' BlS LL l. :fl' "'... I Li' ·v. 11:• I l_H?' '! :\ !. !· t"tl .µ 3 . I··: 2L C: ! ti! "~E'1041 ,;:,p ,):1;1:,\;1 Q) 1 0 L iii: I h u ~14 pit,,,i~i:~r: ·· l"i't""1"c!.9mm~:!1~1 T ±,c,~ •d••... ;:,.. i•0:1'·',....,..... \···········•·•:J"'':,•, c:•: .. :: .. _:_:_·rn: T:1.::,1;c.•:1··!•~_:·::.~::·•:·:·:...:...:..; "1••1.•. ::'1•:,: • I i:d'J,!h n=r+..Tl-...' ::;1:;:~ C: li ~f l~'Ullfl •ut nu ~f 2 0 1 --,~, ii 7.: ··•./J'hl';;:;);:],i..t;j."···h•·;:".l''.j1;::1•• u fr~~t }}~:!- !!U !Ei If:. U! ii!! Ii;:::-::· ~:! i ill:: i!il (T:.-1 •••· ..,;).: .... -1 ..... -,4-.-.-\ ....,.,1;"1:)i'i'/:r'/C:/2,q....J,," ..T,,1,- ....: ::,~i-niH ~!H~EJ:fil:i;;.'. i:::' Q) .,.,1·· 111•1rr..t1 r" .µ !-++:.;·.,-,+.,.~; ~;;; '.';:; ::::1::: "T ::•1 ,,,. n t fi ;:;+.·;:::::\;::·I;~: ::;;[:;:- :::.,::;. ~: tf----!=rl·r-i:I ;~:: :::1 ;;; 1 1 ·oo· °'"... 'l'"l""l""l·· "' tr: ,-:!-+ •[1·.. 1·,..,..1·•1·. ·+ -~ · tffii"'~'":l::::i:;:•1·m1.,t:1~::ij····~ti' , "f ·h·.• •.,, ftt• ~, .,,: .•i'/.'11".•. -.1.·r.~· ·. "U". I t .,,.,., •,,.. --•· t -53- indicates some relationship between the two pollutants in the past few years. The figure also indicates a change in the monitoring of sulfates probably occurred between 1967 and 1969, possibly due to the change in filter brand. In a report by TRW Transportation and Environmental Operations9, ambient concentrations of sulfur dioxide and sulfate were shown to have a geographical relationship. This relationship is illustrated in Figure VI-3. The data indicate that sulfur dioxide and sulfate levels found in coastal areas differ from those found in inland areas; at a given sulfur dioxide level, sulfates are higher in inland areas. • • -fi4- • ~ so Emissions (Los Anqeles County) E 2 ..cc.10 so Concentrations (Composite of data from Los Angeles, 1000 L C. 25 A 2 ~ Long Beach and Pasadena - Los Angeles Zone) "'C ~ 0 SO~ Concentrations (Composite of data from Los Angeles, 900 I- M Lenox and West Los Angeles - Los Angeles Zone) -~..., 90 E "'... ----"':::,.. aoo l tao ~20 (l) C u 0 C ~ 0 -~..., >, 700 u 70 "'... 0"' N ..., 0 C (/) (l) ----"'C u 0 I- 600 i: 60 §15 ~ I u X VI II C :s:"' ... 0 0 0 0 -~ 500 >.50 (/) 0 VI ~ A 0 0 I (l) A 01 -~"' -~ 01 E 0"' A A I UJ "' 400 .,_ 40 ~,a A 0 N 0 > IA 0 < (/) (l) A ~ 0 1962 1965 1970 1975 Year FIGURE VI-1 SULFUR DIOXIDE EMISSIONS AND AMBIENT SULFUR DIOXIDE AtlD SULFATE CONCENTRATIONS LOS ANGELES COUNTY 1962~1974 • 0---0 S02 Annual Average Composite of data from 0 S04 Annual Average Los Angeles ~ CT) • Reseda E West Los Angeles C> ----::,. Lennox ~ "I c:: :,, 0 ::, ::, ·~.., 20 2.0 c:: 5,... ..,"' "'~ c:: :,, (l) < u ct) c:: -s 0 u 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Year FIGURE VI-2. TREND OF ANNUAL AVERAGE SULFATE AND SULFUR DIOXIDE CONCENTRATIONS ARB-1976 . 1965-1974 • 20~------, EASTERN - INLAND CENTRAL 1 SB ...,~ ...... E en ..3 ~o ~ ..J :::, V, w ~ "'w ~ ~5 "'.:;(w ------_Estimated Background Sulfate >- 0 10 W 30 ~ 50 60. Yearly Average Sulfur Dioxide (µg/m3) FIGURE VI-3. AEROMETRIC RELATIONSHIP BETWEEN SULFATE AND SULFUR DIOXIDE IN THE METROPOLITAN LOS ANGELES AREA • Coastal Stations ~ Eastern - Inland Stations 6 Central Stations A ·Intermediate, Central - Eastern Stations DATA SOURCES: WLA - West Los Angeles (LA APCD 1969-1972)* LB - Long Beach (NASN 1968 - 1970) LEN - Lennox (LA APCD 1969-1972)* SNT - Santa Ana (NASN 1969) ANH - Anaheim (NASN 1969) RES - Reseda (LA APCO 1969-1972)* PAS - Pasadena (LA APCO 1972)* DTLA - Downtown L,,s Angeles (LA APCD 1969-1972)* SB - San Bernadir;c (SB APCD 1972 & N1\SN 1968-1969) FNT - Fontana (SB APCD 1972) AZ - Azusa (LA APCD 1972)* * Los Angeles APCD SO data have been corrected to allow for systematic round off error; the LA APCD reports all so2 values from Oto ,015 ppm as .01 ppm. SOURCE: Reference 9 -57- • VII. REVIEW OF MEASUREMENT TECHNIQUEs12 The major problems in the determination of ambient sulfate concentrations occur in the sample collection and analysis. Different techniques are used by the various agencies. Although all of the local and federal agencies in the South Coast Air Basin collect 24-hour samples on glass fiber filters using high-volume samplers, similarities end at this point. All the agencies ·cut the filters into portions to eliminate interferences between the test procedures for other substances in subsequent analyses, but the fashions in_which the agencies div_ide the filters ar-e different, as shown in Figure VII-1. For sulfate analysis, the EPA uses eight percent of the 8"xl O" filter, the Los Angel es and the Riverside Zones use 25 percent and the San Bernardino Zone uses 19 percent. These differences may be significant because the density of collected particles is probably not uniform across the filter media. The Southern California APCD Zones use the barium chloride turbidimetric procedure and NASN and CHESS use the methylthymol blue procedure for analysis of sulfates. A.· Methods for Sulfates Atmospheric sulfate samples are usually collected using high-volume filters with glass-fiber filter sheets; occasionally, cascade impactors are used. Some of the difficulties with the filter methods are: the sampling volume (or flowrate), the catalytic oxidation of S02 to S04 on the surface of the filter, and the interferences in the analytical method arising from other substances extracted from the glass fibers. A number of methods for total atmospheric sulfate concentrations are available. Comparisons of these analytical methods have been made by the Rockwell International Science Center, the Air and Industrial Hygiene Laboratory of the California Department of Health, the Lawrence Berkeley Laboratory, the Crocker Nuclear Laboratory, and EPA's Environmental Monitoring and Support Labor,~ory. Some of the tech niques and their problems are shown below: 1. Turbidimetry a. Methods 1) Barium salt 2) 4-Amino-4'-chlorobiphenyl 3) 2-Aminopyrimidine b. Advantages 1) Simplicity c. Disadvantages 1) Possible interference from colloidal organic matter, filter media and colored material 2) Coprecipitation 3) Poor reproducibility -58- 2. Colorimetry with Color Decrease a. Methods ll Barium rhodizonate 2 Morin or hydroxyflavone and thorium b. Advantages - None c. Disadvantages ll Difficulties in precision with a subtractive method 2 Lack of sensitivity 3. Colorimetry with Color Increase a. Methods 1) Barium chloranilate abl Cation interference Centrifugation or filtration needed cdl Phosphate, oxalate and bisulfite interfere Thought by some to be one of the best methods 2) Methylthymol blue a) Interfering heavy metals have to be removed by ion- exchange chromatography bl Filtration of barium sulf~te necessary C Range 0.3 to 45 µg so4=/m of air d) Interference by oxidation of dye in alkaline solution e) Precision at lower concentrations needs more study f) Colored blank interferes 3) Reduction to H2S and reaction with N,N-dimethyl-p-phenyl enediamine to give methylene blue a) Complicated procedure 4) Reduction to H2S and reaction with ferric ion and o phenanthroline to give the ferrous o-phenanthroline complex a) Complicated procedure b) Nitrite and other H2S precursors interfere 5) AIHL Microchemical methodl3 a) Sensitive to aliquot size 4. Quenchofluorimetry a. Methods 1) Morin or hydroxyflavone with thorium b. Advantages 1) Simplicity 2) Sensitivity potential high c. Disadvantages 1) The difficult problem of measuring a decrease in fluorescence 5. Fl uorimetry a. Methods 1) Reduction to hydrogen sulfide and reaction with a non fluorescent mercury derivative of a powerful fluorogen to give that fluorogen b. Advantages 1) High order of sensitivity c. Disadvantages l} Complexity of procedure 6. Ring Oven a. Methods 1) Barium chloride - potassium permanganate b. Advantages 1) Simplicity c. Disadvantages 1) Precision depends on technique and eye of the experimentors - 2) Interferences are phosphate, oxalate, sulfite 7. Polarography a. Methods 1) Indirect with lead or barium nitrate a) Filtration or centrifugation necessary with consequent problems of absorption and poorer precision 2) Direct square-wave polarography a) Ion exchange chromatography necessary to remove interferences • -60- 8. Atomic Absorption a. Methods 1) Barium 2) Lead 3) Calcium b. Advantages 1) The measurement sensitivities of the metals used to precipitate sulfate are of value in this method c. Disadvantages 1 ) All the usual problems of indirect methods and especially those involving precipitation with excess metal salt followed by subsequent measurement of residual cation. 2) Usual interferences and especially the strong interference from phosphate in the calcium method 9. Gas Chromatography a. Methods 1) Reduction to H2S and measurement of the H2S by gas chromatography with flame photometric detectors. 10. Potentiometry and especially Selective Ion Electrodes a. Methods 1) Direct selective sulfate detector a) No satisfactory detector of this type. However, the field is advancing rapidly so a satisfactory electrode could be developed soon 2) Indirect ion selective electrode for sulfate .. a) Lead selective electrode (1) Most potential at moment (2) Method involves titration with a lead salt (3) Interferences would be any other anions that could precipitate lead. For the method to be workable the effect of these interfering anions would have to be cancelled. (4) Reasonable sensitivity 11. Flame Photometry a. Methods l) Similar to gas chromatography method; but essentially aspira tion of sulfate solution into a hydrogen-rich flame and measurement of the emission spectra 12. X-ray Fluorescence a. Methods 1) Essentially a laboratory method to measure sulfur If all the sulfur were present as sulfate, this might be a good way to measure it. b. Advantages 1) Fast method of analysis, because of sophisticated instrumentation, this is a good method for collection in the field and analysis in a central laboratory. c. Disadvantages 1) Other sulfur compounds would be measured. 2) Expensive instrumentation not available to most labs. B. Methods for Sulfuric Acid Glass-fiber filters are generally used for collection of ambient sulfuric acid samples. Occasionally, paper or membrane filters, impingers containing aqueous solutions, dry impingers in cascade centripetors, or sonic impaction on copper discs or planchets are used. With the separation of H2S04 from other sulfates, the various methods described in the sulfate section ca9 be used. Techniques in use to determine H2S04 are shown below: 2 1. Colorimetry a. Methods 1) Vanadate a) Simple procedure b) Sensitive to 5 µg H2S04 c) Average error 9.3% 2) Barium chloranilate a) H2S04 separated from other sulfates by elution with isopropanol b) Filtration necessary c) Colored material in the extract interferes, as does any anion which precipitates barium 3) West-Gaeke a) Procedure consists of evaporation of H2S04, reduction with copper and determination of so2 colorimetrically b) Complex procedure c) Ammonium sulfate is also measured -62- 4) Other colorimetric and fluorimetric methods described in the sulfate section could be used once H2S04 is separated from other sulfates 2. Coulometry a. Methods 1) As in West-Gaeke Method but S02 titrated 3. Flame Photometry: As above but SOz measured with flame photometer 4. Titrimetry a. Methods 1) Sodium hydroxide residual titration method 2) Tetraborate residual titration method 3) Separation of H2S04 by diffusion at elevated temperatures and titration with barium perchlorate using thoron I as indicator. 5. Square-wave Polarography: Volatile H2S04 separated bv diffusion and determined. Method more rapid than titration Additional information on sulfate and sulfuric acid measurement techniques hgve been published by the Brookhaven National Laboratory.14 -63- , L ' 10" ,----- r----,-----, 1 I I 4" I I I I 8" 2" 1¼11 8" I 5" I I I }}}}{({}}}{ I I I____ _ 1 J :_ _ _ _ _ 11 11 I 1111 II National Air Surveillance Los Angeles and Riverside Network Procedures Zone Procedures I a,_,,. 10" 10" I I-----, r- -- - -. 7 * Exposed portion of filter I indicated by area within I I dashed lines. one of I three 8" 3/4" * Shaded region indicates 8" I 1-3/ 4'1 l-3/ 4"1 2.~ I used 3/4" portion used for sulfate I analysis. I I I I_ __4!<4 __II j I___ _ _j Community Health and San Bernardino Zone Environmental Surveillance Procedures System Procedures FIGURE VII-1 DIVISION OF EXPOSED GLASS-FIBER FILTERS FOR SULFATE ANALYSIS BY THE VARIOUS AGENCIES ARB 1976 • VI I I. REFERENCES 1. Hidy, G. M., et al., "Characterization of Aerosols in California (ACHEX),'' Rockwell International, Science Center, Final Report, ARB Contract No. 358. April 1975. 2. Cahill, T. A., et al., "Regional Monitoring of Smog Aerosols," Crocker Nuclear Laboratory, UCD, Annual Report, ARB Contract No. 2-005, November 1, 1974. 3. Cahill, T. A., et al., "Contribution of Freeway Traffic to Airborne Particulate Matter," Crocker Nuclear Laboratory, UCD, Final Report, ARB Contract No. 502, June 15, 1973. 4. Roberts, P. T. and S. K. Friedlander, "Conversion of S02 to Ambient Particulate Sulfates in the Los Angeles Atmosphere," presented at Proc Health Consequences of Environmental Controls, Durham, NC, April 17-19, 1974. 5. Appel, B. R. and J. I. Wesolowski, "Impact of Motor Vehicle Exhaust Catalysts on Air Quality," Air and Industrial Hygiene .. Laboratory, California Department of Health, Annual Report, ARB I Contract No. 3-985, Berkeley, CA, August 1975. 6. "Los Angel es Ca talyst Study, Operations Summary," Annua 1 Report Environmental Monitoring and Support Laboratory, Research Triangle Park, NC, July 15, 1975. 7. Robinson, E. and R. C. Robbins, "Source, Abundance. and Fate of Gaseous Atmospheric Pollutants,'' Stanford Research Institute, Project PR-6755 for the American Petroleum Institute, June 1_969. 8. "Sul fates Background Paper," National Science Foundation, Office of Energy R &D Policy, October 1974. 9. Trijonis, J., et al., "An Implementation Plan for Suspended Particulate Matter in the Los Angeles Region," Final Report, TRW Transportation and Envi ronmenta 1 Operations, prepared for the EPA, Reg ion IX, San Francisco, CA, March 1975. 10. Larsen, R. I., "A Mathematical Model for Relating Air Quality .. Measurements to Air Quality Standards," EPA (Office of Air Programs), Research Triangle Park, NC, November 1971. 11. Holmes, J. R., "An Assessment of the Aerosol-Visibility Problem in the South Coast Air Basin," ARB Staff Report, October 28, 1975. 12. Hauser, T. R., ''Monitoring of Oxides of Sulfur and Nitrogen and Related Sal ts," presented at · the Conference on Health Effects of Atmospheric Salts and Gases of Sulfur and Nitrogen in Association with Photochemical Oxidanf; ARB Contract No. 3-197, Newport Beach, CA, January 7-8, 1974. 13. Hoffer, E. and E. L. Kothny, "A Micro-method for Sulfate in Atmospheric Particulate Matter," AIHL Report No. 163, Berkeley, CA, July 1974. 14. Forest, J. and L. Newman, "Ambient Air Monitoring For Sulfur Compounds A Critical Review," Brookhaven National Laboratory, J. Air Poll .Control Assoc.; 23, (9), 76 (1973). -65- DTS-76-1 OO lllllllllliilllililiiilllillll (s ' 07800