&EPA United States Environmental Protection Agency Office of Air Quality Planning and Standards Research Triangle Park NC 27711 EPA-450/3-78-031 June 1978 Air Assessment of Human Exposures to Atmospheric Benzene Final ------- EPA-450/3-78-031 Assessment of Human Exposures to Atmospheric Benzene by Susan J. Mara and Shonh S. Lee SRI International Menlo Park, California Contracts No. 68-01-4314 and 68-02-2835 EPA Project Officer: Richard J. Johnson Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Air and Waste Management Office of Air Quality Planning and Standards Research Triangle Park, North Carolina 27711 June 1978 ------- This report is issued by the Environmental Protection Agency to report technical data of interest to a limited number of readers. Copies are available free of charge to Federal employees, current contractors and grantees, and nonprofit organizations - in limited quantities - from the Library Services Office (MD-35) , U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; or, for a fee, from the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161. This report was furnished to the Environmental Protection Agency by SRI International, Menlo Park, California, in fulfillment of Contracts No. 68-01-4314 and 68-02-2835. The contents of this report are reproduced herein as received from SRI International. The opinions, findings, and conclusions expressed are those of the author and not necessarily those of the Environmental Protection Agency. Mention of company or product names is not to be considered as an endorsement by the Environmental Protection Agency. Publication No. EPA-450/3-78-031 11 ------- CONTENTS LIST OF ILLUSTRATIONS vii LIST OF TABLES ix PREFACE xiii ACKNOWLEDGMENTS xv I SUMMARY 1 II BENZENE IN THE ENVIRONMENT 7 A. Introduction 7 B. Nonatmospheric Benzene 9 C. Chemical and Physical Properties of Benzene .... 11 III CHEMICAL MANUFACTURING FACILITIES 17 A. Sources 17 B. Methodology 25 C. Exposures 33 IV COKE OVENS 39 A. Sources 39 B. Methodology and Exposures 42 V PETROLEUM REFINERIES 51 A. Sources 51 B. Methodology 56 1. Refining of Crude Oil 56 2. Storage and Transfer of Pure Benzene 60 C. Exposures 62 VI SOLVENT OPERATIONS 65 A. Sources 65 B. Methodology and Exposure 67 111 ------- VII STORAGE AND DISTRIBUTION OF GASOLINE . . 75 A. -Sources 75 1. Storage 75 2. Distribution 77 B. Methodology and Exposures 78 VIII URBAN EXPOSURES 85 A. Sources 85 B. Methodology and Exposures 88 1. Urban Exposures from Automobile Emissions ... 88 2. Urban Exposures from Gasoline Service Stations . 97 IX SELF-SERVICE GASOLINE . . .' Ill A. Sources Ill B. Methodology and Exposures 114 X ASSESSMENT OF TOTAL EXPOSURE 117 A. Introduction 117 B. Determination of an Individual's Use of Time .... 118 C. Distribution Into Population Subgroups 122 D. Selection of Applicable Exposure Data . . . . .. . . 125 E. Summary of Exposures 132 BIBLIOGRAPHY . . R-l APPENDICES A. Diagrams of Various Benzenes-Related Operations . . . A-l B. Emission Rates and Population Exposures from Chemical Manufacturing Facilities B-l C. Population Exposures from Coke-Oven Operations by Location C-l D. Population Exposures from Petroleum Refineries by Location D-l E. Partial List of Hydrocarbons and Additives Contained in Gasoline E-l IV ------- LIST OF ILLUSTRATIONS III-l Benzene Derivatives and Their Uses 21 III-2 Dispersion Modeling Results for Each Type of Source Category 29 III-3 Predicted Annual Average Benzene Concentrations in the Vicinity of Selected Chemical Manufacturing Facilities . 36 III-4 Comparison Between Predicted Annual Average and 8-Hour Worst Case Benzene Concentrations in the Vicinity of Two Chemical Manufacturing Facilities . 37 IV-1 Dispersion Modeling Results for Coke-Oven Operations . . 46 V-l Monitoring Data for Gulf Alliance Refinery, Belle Chasse, Louisiana 53 V-2 Dispersion Modeling Results for Three Size Categories of Petroleum Refineries 59 VI-1 Sampling Data for Three Solvent Operations 68 VII-1 The Gasoline Marketing Distribution System in the United States 76 VII-2 Estimated Dispersion Curve for a 3-Tank Gasoline Bulk Terminal 81 VII-3 Estimated Dispersion Curve for a 10-Tank Gasoline Bulk Terminal 83 VIII-1 Isopleths (m/sec) of Mean Annual Wind Speed Through the Morning Mixing Layer 92 VIII-2 Results of Atmospheric Monitoring in the Vicinity of Urban-Suburban Gasoline Service Stations, Summer, 1977 . 99 VIII-3 Results of Atmospheric Monitoring in the Vicinity of Rural-Mountain Gasoline Service Stations, Summer, 1977 . 100 VIII-4 Regression Curves Developed From API Atmospheric Monitoring Data Collected in the Vicinity of Gasoline Service Stations 109 ------- TABLES 1-1 Summary of Estimated Population Exposures to Atmospheric Benzene from Specific Benzene Emission Sources 3 1-2 Summary of Estimated Total Exposures of People Residing in the Vicinity of Atmospheric Benzene Sources • 5 II-l Estimated Benzene Levels in Food 11 II-2 Properties of Benzene 12 III-l Locations and Capacities of Plants Using Benzene as an Intermediary Agent in the Manufacture of Various Chemical Compounds 18 III-2 Atmospheric Benzene Concentrations Sampled at Benzene-Consumption Facilities .... 22 III-3 Major Chemical Compounds Other than Benzene Emitted from Chemical Manufacturing Facilities 23 III-4 Emission Factors and Characterizations for Benzene-Consumption Plants 24 III-5 Rough Estimates of Ambient Ground-Level Benzene Concentrations (8-Hour Average) 26 III-6 Rough Estimates of Ambient Ground-Level Benzene Concentrations (8-Hour Average) per 100 g/s Emission Rate 28 III-7 Estimates of a 8-Hour Worst Case Benzene Concentrations Based on Average of Three Emission Source Categories ... 30 III-8 Estimated Population Exposed to Benzene From Chemical Manufacturing Facilities, by State 34 IV-1 Estimated Size and Productive Capacity of By-Product Coke Plants in the United States on December 31, 1975 . . 40 IV-2 Ambient Levels of Benzene Within a Coal-Derived Benzene Production Plant 41 IV-3 Atmospheric Benzene Emission from the Coking and Recovery Plants in Czechoslovakia 42 IV-4 Partial List of Constituents of Coke Oven Emissions . . 43 IV-5 Rough Estimates of 8-Hour Worst Case Benzene Concentrations per 100 g/s Emission Rate Using the PAL Dispersion Model 47 IV-6 Estimated Population Exposed to Benzene from Coke Ovens, by State 50 VI ------- V-l Petroleum Refineries Producing Aromatics, by State .... 52 V-2 Atmospheric Benzene Concentrations at Distances Greater than 1 KM from Perimeter of Petroleum Refineries 54 V-3 Results of Ambient Benzene Monitoring in the Vicinity of Petroleum Refineries 55 V-4 Calculation of Emission Factors for Petroleum Refineries . 57 V-5 Summary of Emission Factors for Pure Benzene Storage and Transfer 61 V-6 Estimated Population Exposed to Benzene from Petroleum Refineries, by State 63 VI-1 Industries and Manufactured Products Possibly Using Benzene as a Solvent 66 VI-2 Average Number of Employees per Plant for Selected Solvent Operations 69 VI-3 Number of Plants and Employees for Solvent Operation with High Potential for Benzene Emissions 70 VI-4 States with the Highest Potential for Atmospheric Benzene from Solvent Operations 72 VII-1 Emission Factors for Benzene Losses from Gasoline Storage and Distribution 79 VIII-1 Results of Ambient Benzene Monitoring in Urban Areas with High Industrial Activity 86 VIII-2 Typical Liquid Volume-Percent of Benzene in Gulf U.S. Gasolines, October 1976 87 VIII-3 Benzene Concentration in Different Grades and Seasonal Blends of Gasoline 88 VIII-4 Estimates of Annual Average Benzene Concentrations in Four Urban Areas 90. VIII-5 Estimates of Average Annual Benzene Concentrations for Cities with Population Exceeding 1,000,000 93 VIII-6 Estimates of Average Annual Benzene Concentrations for Selected SMSAs 95 VIII-7 Urban Population Exposures Related to Automobile Emissions 96 VIII-8 Service Station Density in Four Metropolitan AQCRs .... 98 VIII-9 Rough Dispersion Modeling Results for Gasoline Service Stations 103 VIII-10 Emission Factors for Benzene Losses at Gasoline Service Stations 104 VI1 ------- VIII-11 VIII-12 IX-1 IX-2 IX-3 IX-4 IX-5 X-l X-2 X-3 X-4 X-5 X-6 X-7 X-8 X-9 X-10 X-ll X-12 Determination of Weighted U.S. Average Wind Speed 106 Estimates of Annual Average Benzene Concentrations in Urban Areas from Gasoline Service Stations Based on the Hanna-Gifford Dispersion Model 107 Self-Service Operations 112 Gasoline Market Share of Self-Service Stations in Four AQCRs, Spring 1977 113 Gasoline Market Share of Self-Service Stations in Two Metropolitan Areas, 1976 114 Sampling Data from Self-Service Gasoline Pumping 115 ... 116 ... 119 Estimated Population Exposed to Benzene from Self-Service Gasoline Percentage of Time Spent per Week in Major Types of Activities by Employed Men in Urban Areas, 1975 Percent of Those Employed by Place of Residence and Commuting Time to Work 121 Estimated Annual Distribution of Time Spent in Various Activities and Locations 123 Distribution of the Population into Groups Affected by Other Benzene Exposure Settings 124 Results of Battelle Atmospheric Monitoring Study 126 Traffic Volume and Density During Benzene Sampling Periods at Site 2 127 Benzene Concentrations in Remote Air Samples from the Continental United States 128 Benzene Concentrations in the Vicinity of Major Intersections Based on Dispersion Modeling 130 Benzene Exposure Settings in Vicinity of Specific Locations 131 Estimate of Total Exposure for Each Scenario 135 Example Calculation of Total Exposure for Two Benzene Source Categories Summary of Estimated Total Exposures of People Residing in the Vicinity of Atmospheric Benzene Sources 137 139 vm ------- PREFACE There is substantial evidence that concentrations of benzene encountered in the workplace (both in the United States and elsewhere) have caused blood and bone marrow diseases (e.g., blood dyscrasia, pancytopenia) and leukemia (especially myelogenous leukemia). As current U.S. Environmental Protection Agency (EPA) policy states that there is no zero risk level for carcinogens, benzene has been listed by EPA under Section 112 of the Clean Air Act as a hazardous air pollutant. To determine what regulatory action should be taken by EPA on atmospheric emissions of benzene, three reports have been prepared: (1) a health effects assessment, (2) a population exposure assessment, and (3) a risk assessment document based on the data in the first two assessments. This document is the human population exposure assessment and presents estimates of the numbers of people in the general population of the United States exposed to atmospheric concentrations of benzene from specific sources. ix ------- ACKNOWLEDGMENTS It is a pleasure to acknowledge the cooperation and guidance given by several individuals of the U.S. Environmental Protection Agency. Mr. Richard J. Johnson, Office of Air Quality Planning and Standards, Strategies and Air Standards Division, generously provided data and direction throughout the study. Messrs. Phillip L. Youngblood and George J. Schewe (Office of Air Quality Planning and Standards, Monitor- ing and Data Analysis Division) conducted dispersion modeling, offered guidance about the application of their results, and reviewed draft documents. Additional assistance was provided by many individulas in the Emission Standards and Engineering Division of the Office of Air Quality Planning and Standards. Mr. Alan P. Carlin, Office of Research and Development, and Mr. Joseph D. Cirvello, Office of Air Quality Planning and Standards, were the Project Officers. Mr. Benjamin E. Suta, SRI project leader, gave vital support and provided useful input throughout the study. Mr. Robert E. Freeman and Dr. Stephen L. Brown provided encouragement to the authors and acted as liaisons with other interested parties. Mr. Michael Smith patiently edited and re-edited the study. Mrs. L. H. Wu and Ms. Grace Y. Tsai were responsible for all graphics. ------- I SUMMARY This report is one in a series that SRI International is providing on a quick-response basis for the U.S. Environmental Protection Agency (EPA). Populations-at-risk to selected pollutants are being quantified for input to other, more inclusive studies. The primary objective of this study was to estimate the environmental exposure of the U.S. popu- lation to atmospheric benzene emissions from specific sources. In this estimate it was assumed that individuals residing in the vicinity of benzene sources spend 24 hours of each day in the same location. To estimate more representative exposures, a second objective was added— to make rough estimates of individuals' total exposures by defining "total exposure" as the sum of exposures to all benzene sources, including those in nonresidential areas, within a designated period. The seven primary sources of atmospheric benzene considered in this report are chemical manufacturing facilities, coke ovens, petroleum refineries, solvent operations, gasoline storage and distribution centers, self-service gasoline stations, and urban exposures related to automobile emissions and evaporation from gasoline service stations. Data were quite limited for this study. When data were available, source locations were identified and benzene emission rates were calcu- lated. Atmospheric environmental concentrations of benzene were then estimated by applying approximate, dispersion modeling results developed * by EPA. Population exposed to concentrations of 0.1 ppb and greater were estimated. When data were unavailable, best estimates were developed to provide a reasonable basis for comparison. Total exposures were estimated by developing scenarios that repre- sent the typical behavior of individuals living in the vicinity of benzene * The detection limit of current sampling techniques. ------- sources. Based on available sociological, statistical, and ambient monitoring studies, the following variables were estimated: percentage of time spent in activities away from the residence such as shopping and working; proportion of the population following given living patterns; and typical benzene concentrations associated with each activity. The percentage of time spent in 1 year in various activities wad multiplied by the associated benzene concentration and summed to determine an individual's total exposure. The resulting estimates are subject to considerable uncertainty in regard to: (1) the quantity of benzene emissions, (2) benzene production and consumption levels, (3) source locations, (4) control technologies employed, (5) deterioration of control technologies over time, (6) physical characteristics (e.g., stack height) of benzene sources, (7) population density in the vicinity of sources, (8) living patterns of the exposed population, and (9) relationship of ambient monitoring data to dispersion modeling estimates. Given these complex and variable factors, the accuracy of the estimates could hot be assessed quantita- tively. Nevertheless, the estimates, although not precise, approximate expected conditions. Table 1-1 summarizes results of the source-specific assessment. Urban exposures constitute the largest sources. Chemical manufacturing facilities are second, with more than 7 million people exposed over a wide range of exposure levels. Petroleum refineries are sources of benzene exposures for more than 5 million people. For approximate comparison of different emission sources, exposures are calculated in similar units by multiplying the number of exposed population by the annual average benzene concentration within each range. These values were then summed for each emission source. Thus, the units become ppb-person-years (Table 1-1). We assumed that people who use self-service gasoline are exposed to this emission source for 1.5 hours per year. ------- Table 1-1 SUMMARY OF ESTIMATED POPULATION EXPOSURES TO ATMOSPHERIC BENZENE FROM SPECIFIC BENZENE EMISSION SOURCES' Source Number of People Exposed to Benzene Concentrations (ppb) 8-hour Worst Case: 2.5-25.0 Annual aver age : 0.1-1.0 Chemical manufacturing Coke ovens Petroleum refineries Solvent operations Storage & distribution of gasoline Automobile emissions - urban Gasoline service stations - urban People using self-service gasoline 6,000,000 300,000 5,000,000 d e 69,000,000 20,000,000 25.1-100.0 1.1-4.0 1,000,000 3,000 45,000,000 900,000 100.1-250.0 4.1-10.0 200,000 >250.0 > 10.0 80,000 g Total0 7,300,000 300,000 5,000,000 — 110,000,000 21,000,000 37,000,000 Comparison Among Sources (106 ppb-person-years) 8.5 0.2 2.5 — 150.0 12.0 1.6 u> Assumes that people living in the vicinity of benzene sources spend 24-hours of each day in that location. Vi 3 To convert to yg/m , multiply each exposure level by 3.2; to estimate one-hour worst case concentrations multiply 8-hour worst case by 10. Population estimates are not additive vertically, because double-counting exists. Totals are rounded to two significant figures. Exact determination is impossible. eEstimated at « 0.1 ppb annual average. The population exposed was not determined but is assumed to be very small. 8-hour worst case is estimated by multiplying each exposure level by 4.1. 8Estimated at 245 ppb for 1.5 hr/yr/person. Source: SRI estimates. ------- The results presented in Table 1-1 show that urban exposures have the highest weighted human exposures. Next are chemical manufacturing plants, followed by petroleum refineries. These results differ because they are weighted by the number of people exposed to a particular level of atmospheric benzene. Thus, they provide a useful basis for compari- son and, assuming a linear dose-response relationship, are directly related to human health. The total exposure for individuals living in the vicinity of benzene sources (assuming the several scenarios of living patterns discussed in Chapter X) is shown in Table 1-2. When this exposure is compared with those shown in Table 1-1, several significant differences are evident. The levels to which more than 90% in the lowest range are exposed have been increased sufficiently to place these people in the second range because benzene exposure levels for most activities considered (i.e., shopping, commuting, working) are higher than 1.0 ppb. Therefore, the weighted sum for all exposures is higher than the original estimate. This analysis indicates that living patterns affect annual average benzene exposures—generally by increasing those exposures because higher benzene exposures occur in nonresidential settings. As indicated above, the estimates given in this report are subject to considerable uncertainty; they thus require further monitoring and sampling data for a more complete assessment. Despite the insuffi- ciency of data, however, the fact remains that the population exposed is substantial. Potential health effects from the estimated exposures will be addressed in another report being prepared by the EPA Cancer Assessment Group. ------- Table 1-2 SUMMARY OF ESTIMATED TOTAL EXPOSURES OF PEOPLE RESIDING IN THE VICINITY OF ATMOSPHERIC BENZENE SOURCES Vicinity of Residence Chemical manufacturing Coke ovens Petroleum refineries Urban areas Number of People Exposed Annual Average Benzene Concentrations (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 > 10.0 3,900,000 3,100,000 200,000 80,000 200,000 100,000 3,250,000 1,750,000 110,000,000 Totalt 7,300,000 300,000 5,000,000 110,000,000 Comparison Among Sourcestf (10^ ppb-person-year) 10.0 0.2 4.5 250.0 The term "total exposures" is used to mean the sum of an individual's exposure to atmospheric benzene from a variety of activities during a year. This assumes that people spend part of their time away from their residence, resulting in exposures to different benzene concentrations depending on their activity (i.e., commuting to work, shopping, traveling on personal business). Nonurban exposures are not included in this analysis but are expected to range from undetectable to 1.0 ppb. Rounded to two significant figures. median values shown in Table X-10 were used for this calculation instead of the mid-point of the ranges. This allows a better comparison with Table 1-1. Source: SRI estimates. ------- II BENZENE IN THE ENVIRONMENT A. Introduction The primary objective of this study has been to rank specific benzene emission sources by estimating the atmospheric exposure of the U.S. population to benzene from each source. The ranking of sources will serve as input for establishing regulatory priorities. Implied in this analysis is the assumption that individuals living near the sources spend 24-hours of each day in that location and they are only exposed to emissions from that source. However, because benzene sources are numerous and diverse, there is reason to believe that certain individuals have significantly different exposures from those estimated by this method and are exposed to emissions from more than one source. Therefore, after public review and comment on the initial draft of this study, a second objective was added to make first-cut estimates of total exposure to individuals living in the vicinity of benzene sources. Total exposure is the sum of the exposures to all benzene sources over a designated period (e.g., a day or a week). This study is one in a series that SRI is conducting for EPA to estimate populations at-risk to selected pollutants. These studies are generally conducted on a quick-response basis to provide input to other, more inclusive studies. This study has not considered the degree of bio- logical sorption of material. No attempt was required or has been made in this input report to assess potential health effects. Atmospheric sources of benzene are widespread and include natural sources such as forest fires and man-made sources such as automobile emissions. Although benzene is not sampled regularly in any air quality monitoring program, some sampling data do exist. EPA has also conducted dispersion modeling that is applicable to most of the major sources. On the other hand, sample data of benzene concentrations in water, food, and soil are sparse, and those measurements that have been taken have been infrequent and inconsistent. ------- Benzene is commercially produced mainly by petrochemical operations (92%) and on a much smaller level as a coke-oven by-product (8%). Total benzene production in 1976 was approximately 7500 x 10 Ib (3400 x 10 kg) (SRI estimates). Benzene is a constituent of gasoline and crude oil. Pure benzene is used primarily in chemical manufacturing processes, and in solvent operations. Of all benzene used in chemical and solvent operations, more than 97% is used in chemical processing (SRI estimates). For this report, seven sources of atmospheric benzene were evaluated: chemical manufacturing plants, coke ovens, self-service gasoline stations, petroleum refineries, solvent operations, storage and distribution of gasoline, and urban exposures related to automobile emissions and evap- oration from gasoline stations. These sources have been identified as the major sources of atmospheric benzene (PEDCo, 1977; Johnson, 1977). Although oil spills and discharges represent a potentially significant source of benzene in the environment, the most significant of these occur in remote locations or along coastal areas where population density is low, and the benzene released to the atmosphere from each occurrence is very small. Potential human exposure to atmospheric benzene from oil spills and discharges appears to be negligible. Because few quantitative data were available for this study, all estimates given here are subject to considerable uncertainty. This is related to: quantity of benzene emissions, benzene production and consumption level, source locations, control technology employed, deterioration of control technology over time, and dispersion modeling. The available monitoring data are summarized in the discussion of each source; however, because these data are insufficient, the accuracy of the monitoring results could not be quantitatively assessed. Quality control information was unavailable for much of these data. Comparisons of short-term ambient concentrations indicated by monitoring data with annual average ambient concentrations estimated from dispersion modeling are tenuous. In addition, meterological conditions and in-plant operating characteristics during a sampling period may differ significantly from ------- average conditions. Even with these uncertainties, a comparison of monitoring data with dispersion modeling results suggests that the agreement between the two is sufficient to lend support to the modeled concentrations. B. Nonatmospheric Benzene It is not within the scope of this study to evaluate human exposures to benzene from water, food, or other environmental pathways. However, it is useful to review the available data to provide some basis for comparison. Only limited data on benzene in water are available. A review of benzene sampling data by Howard and Durkin (1974) found that the few freshwater samples analyzed by that time showed only trace levels of benzene. For example, a 1972 EPA study cited in the report identified 53 organic chemicals, ranging from acetone to toluene, in the finished waters and organic waste effluents in 11 plants (of 60 sampled) dis- charging into the Mississippi River. Benzene was not detected in the effluents, but the trace detected in the finished waters suggested another source than effluent discharge. A recent sampling of five benzene production or consumption plants by Battelle (1977a) found benzene levels in water ranging from < 1.0 to 179 ppb (plant effluent). The concentrations at 13 upstream and down- stream sample locations in nearby receiving waters, however, ranged from < 1.0 to 13.0 ppb, with an average of 4.0 ppb. A recent report by the National Cancer Institute (1977) noted benzene levels of 0.1 to 0.3 ppb in four U.S. city drinking water supplies. One measurement from a groundwater well in Jacksonville, Florida showed levels higher than 100 ppb. No indication is given in the report of the sampling methods or the analytical procedures. However, study of the behavior of benzene in the groundwater system and in the drinking water supply system is clearly warranted. One possible source of benzene in the aquatic environment is from cyclings between the atmosphere and water (Mitre, 1976). Benzene is ------- fairly volatile (high vapor pressure of 100 mmHg at 26°C) and has a relatively high solubility (1780 mg/L at 25°C). Consequently, it is reasonable to believe that benzene will be washed out of the atmosphere with rainfall and then evaporated back into the atmosphere, causing a continuous recycling between the two media. The distribution of benzene in the aquatic system is not well-known. Neely et al. (1974) demonstrated a relationship between octanol-water partition coefficients and bioaccumulation potential in fish. The partition coefficient for benzene, which is estimated to be very low, suggests that the bioaccumulation potential in fish is minimal. Benzene uptake by aquatic vegetation has not been studied. Only one study of benzene levels in soil has been conducted. Battelle (1977a) sampled soils in the vicinity of five benzene consumption or production facilities. Their preliminary results from 14 samples showed levels ranging from <1.0 to 191.0 ppb, with an average of 53.0 ppb. In most cases, the highest levels of benzene were found in samples taken closest to the plant. These results indicate that the potential for accumulation of benzene in the soil is significant. Human exposure to benzene in food is not addressed in this report. We note, however, the following information: those few available data that quantify benzene levels in food (Chinn, personal communication, 1977) indicate that it occurs naturally in fruits, fish, vegetables, nuts, dairy products, beverages, and eggs. However, data on concentrations are only available for cooked meat, rum, and eggs (see Table II-l). A report by the National Cancer Institute (1977) estimated that an indi- vidual could ingest as many as 250 yg/day from these foods. L = liter. 10 ------- Table II-l ESTIMATED BENZENE LEVELS IN FOOD (yg/kg) Heat treated or canned beef 2 Jamaican rum 120 Irradiated beef 19 Eggs 2100 Source: National Cancer Institute (1977) C. Chemical and Physical Properties of Benzene Benzene, C,H,, is a nonpolar, nonreactive, highly refractive cyclic oo o aromatic hydrocarbon. In benzene, the C-C bond is 1.38 A long and the o CH bond is 1.08 A long (Ayers and Muder, 1964; MacKenzie, 1962). Under standard conditions, benzene is a clear, noncorrosive, colorless, and highly flammable liquid. Benzene possesses a characteristic odor, similar to that of gasoline. It is relatively soluble in water and is miscible with acetone, alcohol, chloroform, ether, carbon disulphide, carbon tetrachloride, glacial acetic acid, and oils. Pertinent physical properties of benzene are listed in Table II-2. Benzene is quite thermodynamically stable because the resonance energy of its unsaturated bonds is due to the interaction of the six IT electrons that form "doughnut" shaped electron orbitals above and below the plane of the ring. Benzene solubility in water at 25°C is 1800 ppm (0.18 mg/g water). Variation of benzene solubility in water from 1730 to 1800 ppm has been noted (McAuliffe, 1963). The difference is believed to be attributable either to the temperature of the experiment or the precision of the technique. Both salting-in and salting-out (increase or decrease in solubility) phenomena have been observed for benzene in aqueous solution (Giacomelli, 1972). Benzene solubility in salt water and distilled water 11 ------- Table II-2 PROPERTIES OF BENZENE Constant Freezing point, °C Boiling pointj °C Density, at 25°C, g/mL Vapor pressure at 26.075°C, mm Hg Refractive index, njp Viscosity (absolute) at 20°C, cP Surface tension at 25°C, dyn/cm Critical temperature °C Critical pressure, atm Critical density, g/mL Flash point (closed cup), °C Ignition temperature in air, °C Flammability limits in air, vol% Heat of fusion, kcal/mole Heat of vaporization at 80.100°C, kcal/mole Heat of combustion at constant pressure and 25°C (liquid C^H.^ to liquid H20 and gaseous CCL) , kcal/g Solubility in water at 25°C, g/100 g water Solubility of water in benzene at 25C, g/100 g benzene Value 5.553 80.100 0.8737 100 1.49792 0.6468 28.18 289.45 48.6 0.300 -11.1 538 1.5-8.0 2.351 8.090 9.999 0.180 0.05 Source: Ayers and Muder (1964). 12 ------- have been compared, and the results show that solubility decreases as the salt content of water increases (Button and Calder, 1974). A similar decrease in solubility of the water soluble fraction (including benzene) from crude oil was observed (Lee, 1974). These observations reveal that benzene is less soluble in salt water than in fresh water. The vapor pressure of benzene is an important property in assessing the benzene contamination in the gaseous phase. The vapor pressure of 100 mmHg at 26°C indicates that benzene exists environmentally only in the gaseous and the aqueous phases. Benzene is highly stable'. Consequently, chemical reactivity is limited unless the reactions take place under certain extreme conditions (and in the presence of the necessary reagents). When chemical reactions do take place, benzene behaves primarily as a nucleophilic agent, usually with substitution of individual hydrogen atoms rather than addi- tion. The two most common substitutive reactions are nitration and sulfonation. In additive reactions, other reactive chemical agents are added to the unsaturated bonds. Three types of additive reactions are most common: oxidation, hydrogenation, and halogenation. The general environmental fate of benzene can be assessed by exam- ining the degradation processes of oxidation, hydrolysis, photolysis, and microbial decomposition. Hydrolysis and microbial decomposition occur primarily in the aqueous phase, whereas oxidation and photolysis can occur in both the aqueous and the gaseous phases. Benzene can be oxidized to a number of different products in the presence of catalysts or at elevated temperatures and pressures. Under extreme conditions, benzene has been observed to oxidize completely to water and carbon dioxide. In the environment, such extreme conditions rarely exist. Thus, it can be concluded that degradation of benzene by oxidation is probably negligible. Oxidation in the emission pathways from chemical plants and refineries is conceivable, but no such obser- vations have been reported. 13 ------- The benzene ring does not undergo reaction with water or hydroxyl ions (OH ) unless substituted with a significant number of strong electro- negative groups, or at elevated temperature and pressure. Thus, hydrol- ysis in the environment is assumed to be minimal. Several studies have investigated the wavelength absorption proper- ties of benzene. No appreciable amounts of light at wavelength longer o than 280 nm (2800A) were directly absorbed by benzene dissolved in cyclohexane. A slight shift, however, in wavelength absorption would be more representative of environmental media, such as dissolution in water or adsorption on particular matter. Chien (1965) reported the ultraviolet absorption spectra of liquid benzene in the presence of oxygen under 1 atmosphere. Noyes et al. (1966) found that gaseous benzene only absorbs light at 275 nm or less. Because the atmospheric ozone layer effectively filters out wavelengths less than 290 nm, it appears that direct excitative photolytic reaction of benzene in the environment is unlikely, unless a substantial wavelength shift occurs in the presence of other media. Indirect excitation of benzene may be possible in the presence of certain sensitizers in the water or soil. Photolysis by light with a wavelength of less than 290 nm of benzene in the vapor phase and in oxygenated aqueous solution has been reported. Two types of products, 2-formyl-AH-pyran and cyclopentadiene-carboxaldehyde result (Luria and Stein, 1970; Kaplan et al., 1971). Matsuura and Omura (1974) have reviewed several investigations where atomic oxygen that had been photochemically generated from various sources reacted with benzene to form phenol. Atomic oxygen is generated, for instance, from the photodecomposition with nitrogen dioxide, which is frequently found in high concentration in heavily polluted air (Altshuller, 1971). Labora- tory results conclude that benzene is not completely inert under smog conditions (Laity et al., 1973; Stephens, 1973). The microbial degradation of benzene has received some attention in recent years and it is conceivable that biodegradation of benzene probably occurs under environmental conditions. Benzene has been found to bio- degrade in a waste treatment plant, with the rate of degradation 14 ------- determined by the incubation period and acclimation of the microorganisms. It is safe to conclude, therefore, that benzene can be degraded—but at a very slow rate. In summary, oxidation and hydrolysis of benzene in the environment are unlikely. Photolysis is possible in the natural environment, but the photolysis rate depends on wavelength adsorption and the presence of sensitizers. In a heavily polluted atmosphere, atomic oxygen may cause photochemical decomposition of benzene. Biodegradation of benzene in the environment is also possible, but the degradation rate is quite slow. 15 ------- Ill CHEMICAL MANUFACTURING FACILITIES A. Sources In this section, generation of benzene emissions from the manufac- turing of chemical compounds will be addressed. Producer companies of various compounds (excluding solvents) are listed in Table III-l; their locations and 1976 capacity productions are also included in the table. The Gulf Coast has the highest density of these benzene-consumption facilities. Benzene is used commercially as an intermediate agent in the pro- duction of many chemical compounds. The emissions of benzene from such industrial uses are potentially significant sources of atmospheric benzene. Total U.S. consumption of benzene in 1975 was 108.4 x 10 gal (4.1 x 10 m ) (Anderson, 1976). Figure III-l illustrates the benzene deriva- tives and their uses. Primary use involves the manufacture of such chemi- cals as nitrobenzene, ethylbenzene, maleic anhydride, cumene, phenol, chlorobenzene, cyclohexane, and detergent alkylate. Appendix A contains flow diagrams for some of these processes. Some atmospheric monitoring data were collected in the vicinity of five benzene-consumption facilities by Research Triangle Institute (RTI) (1977). Grab samples were collected for periods ranging from 25 minutes to 12 hours, both on the plant property and within 1 km of the plant boundary. Benzene concentrations ranged from 0.5 to 58.4 ppb. The average benzene concentration for each location is shown in Table III-2. Complete quality control information is unavailable for these samples. Emissions from chemical manufacturing facilities contain many chemical compounds in addition to benzene; some of these compounds have demon- strated toxic and/or carcinogenic properties. Although few data exist about the composition of emissions from various processing facilities, Table III-3 contains a partial list of the major emissions. Individuals 17 ------- Table 111-1 LOCATIONS AND CAPACITIES OF PLANTS USING BENZENE AS AN INTERMEDIARY AGENT IN THE MANUFACTURE OF VARIOUS CHEMICAL COMPOUNDS* oo STATE ALABAMA CALIFORNIA DELAWARE GEORGIA ILLINOIS LOCATION TUSCALOOSA CARSON EL SEGUNOO IRWINDALE RICHMOND SANTA FE SPRINGS DELAWARE CITY CAHTEHSVILLE BLUE ISLAND CICERO COMPANY HEICHHOLD CHEM., INC. WITCO CHEM. STD. OIL CO. OF CALIF. SPECIALTY OHGANICS. INC. STD. OIL CO. OF CALIF. FERHO CORP. STO. CHLORINE CHEM CO.. INC. CHEM. PRODUCTS CORP CLARK OIL & REFINING KOPPEfiS CO.. INC. MORRIS REICMHOLO CHEM.. INC. SAUGET KANSAS EL DORADO MONSANTO SKELLY OIL CO. KENTUCKY ASHLAND ASHLAND OIL. INC. LOUISIANA BATON ROUGE FOSFCR GRANT CO. CAHVILLE COS-MAR. INC. CHALMETTE TENNECO, INC. GEISMAR RUBICON CHEM.. INC. PLAQUEMINE GEORGIA PACIFIC CORP. WELCOME GULF OIL CORP. MARYLAND BALTIMORE CONTINENTAL OIL CO. MASSACHUSETTS MALOEN SOLVENT CHGM. CO.. INC. MICHIGAN MISSISSIPPI MISSOURI NEVADA NEW JERSEY MIDLAND DOW CHEMICAL PASCAGOULA FIRST MISSISSIPPI CORP. ST. LOUIS MONSANTO HENDERSON MONTROSE CHEM.CORP. OF CAL. BOUND BROOK AMERICAN CYANAMID BOUND BROOK UNION CARBIDE ELIZABETH REICHHOLO CHEM., INC. FORDS TENNECO, INC. GIBBSTOWN £. 1. du PONT KEAflNY STO. CHLORINE CHEM. CO. WESTVILLE TEXACO, INC. CAPACITY PRODUCTION JANUARY 1. 1976 (million* of kg! NITRO- BENZENE 6 34 61 38 91 ANILINE 26 46 27 69 ETHYL- BENZENE 440 327 12 260 260 STYHENE 372 272 238 182 MALEIC ANHYDRIDE 6 27 48 14 12 CUMENE 46 60 61 160 4.6 118 PHENOL 68 26 N.A. 40 63 120 18 68 MONO- CHUOHO BENZENE 34 62 N.A. 136 32 DICHLORO- BENZENE IO- «nd PI 1 27° 10' 13 l" » 7* CYCLO- HEXANE DETERGENT ALKYLATE (Un.. •nd Branch) 26 100 98 ------- Table 111-1 (Continued) vo STATE NEW YORK OHIO PENNSYLVANIA PUERTO RICO TEXAS LOCATION NIAGARA FALLS NIAGARA FALLS NIAGARA FALLS SYRACUSE HAVERHILL BEAVER VALLEY BRIDGEVILU CLAWTON FHANKFORO NEVILLE ISLAND PHILADELPHIA CUAYAMA PENUELAS PENUELAS BAYTOWN BEAUMONT BEAUMONT BIG SPRING eORGEH CHOCOLATE BAYOU CORPUS CHRISTI CORPUS CHRISTI CORPUS CHRISTI FREEPORT HOUSTON HOUSTON HOUSTON HOUSTON HOUSTON ODESSA OYSTER CREEK PHILLIPS PORT ARTHUR PORT ARTHUR PORT ARTHUR SEADRIFT SWEENEY COMPANY ICC INDUSTRIES. INC. OCCIDENTAL PETROLEUM SOLVENT CHEM. CO. ALLIED CHEM. CORP. UNITED STATES STEEL AHCO/POLYMERS. INC. KOWEHS CO., INC. UNITED STATES STEEL ALLIED CHEMICAL CORP. UNITED STATES STEEL GULF OIL CORP. PHILLIPS PETROLEUM COMMONWEALTH OIL UNION CARBIDE CORP EXXON CORP E. 1. du PONT UNION OIL CO. OF CALIFORNIA AMERICAN PETROFINA PHILLIPS PETROLEUM MONSANTO COASTAL STATES GAS SUN OIL CO. UNION PACIFIC CORP OOW CHEMICAL ARCO/POLYMERS, INC. THE CHARTER CO. JOE OIL. INC. THE MERICHEM CO. PETRO-TEX CHEM CORP. EL PASO NATURAL GAS DOW CHEMICAL PHILLIPS PETROLEUM CO. ARCO/POLYMERS, INC. GULF OIL CORP TEXACO UNION CARBIDE CORP PHILLIPS PETROLEUM CO. CAPACITY PRODUCTION- JANUARY 1, 1976 (millions of kg) NITRO- BENZENE 141 ANILINE 91 ETHYL- BENZENE 73 JO 43 M8 46 1» lit 100 166 STYRENE 200 41 36 649 46 6B 138 MALEIC ANHYDRIDE, 16 IB 23 CUMENE 206 280 286 64 114 206 118 PHENOL 90 MONO- CHLOHO- BENZENE N.A. 7 N.A. 11 N.A. 260 i ! 90 J27 N.A. 182 DICHLORO- BENZENE 10- «nd P-l N.A. 9 9 CYCLO- HEXANE 98 209 118 118 100 36 118 66 208 261 DETERGENT ALKYLATE ILinur •nd Branch) 102 ------- Table 111-1 (Concluded) STATE TEKAS WEST VIRGINIA WASHINGTON LOCATION TEXAS CITY TEXAS CITY TEXAS CITY CHARLESTON FOLLANSBEE MOUNDSVILLE NATRIUM NEW MARTINSVILLE WILLOW ISLAND ANACORTES KALAMA COMPANY MARATHON OIL CO. MONSANTO STANDARD OIL IINOIANA) UNION CARBIDE CORP KOPPERS CO.. INC. ALLIED CHEM CORP. PPG INDUSTRIES. INC. MOI3AY CHtM CORP. AMERICAN CYANAMIOE STIMSON LUMBER CO. KALAMA CHEMICAL TOTAL CAPACITY PRODUCTION JANUARY 1, 1976 Imllllom of kg) NITRO BENZENE 26 61 27 483 ANILINE 46 22 314 ETHYL- BENZENE 1460C 430 3884 STYRENE 580 382 3211 MALEIC ANHYDRIDE 27 188 CUMENE 88 28 1720 PHENOL N.A. 26 1262 MONO- CHLORO- BENZENE N.A. 41 313 DICHLORO- 8ENZENE 10- >nd P-l 23 120 CYCLO- HEXANE 2706 DETERGENT ALKYLATE ILinnr xd Brtnchl 68 3>3 NJ o SOURCE SRI. 1976 DIRECTORY OF CHEMICAL PRODUCERS. « dud In PEDCO. 1877 N.A. - NOT AVAILABLE I. PRODUCTION CAPACITY FOR ODICHLOROeENZENE ONLY b. PRODUCTION CAPACITY FOR P DICHLOHOBENZENE ONLY c. 1978 DATA SHOWED COMBINED ESTIMATES OF ETHYLBENZENE PRODUCTION AT CHOCOLATE BAYOU. TEXAS AND AT TEXAS CITY. TEXAS. 1977 SRI ESTIMATES SHOW ETHYLBENZENE PRODUCTION ONLY AT THE TEXAS CITY PLANT. ------- ETHYL \ / CYCLO BENZENE / V HEXANE CHLOHO- BENZENE DETERGENT ALKYLATE PHENOLIC \/ SURF AC ALKLD. VPOLYESTER INSECT.- V CARBON. U EPOXY MOLDINGS I FIBERS OIL fcETERGEN THANES / \ADDITIVES RESINS A TANTS RESINS A RESINS LAMINATES I ADHESIVES I COATINGS I MOLDINGS I FIBERS I LAMINATES I ADHESIVES I MOLDINGS I COATINGS SOURCE: HEDLEY, 1975 FIGURE 111-1. BENZENE DERIVATIVES AND THEIR USES ------- residing in the vicinity of chemical manufacturing facilities are, therefore, exposed to a wide variety of chemical compounds in addition to benzene. Table III-2 ATMOSPHERIC BENZENE CONCENTRATIONS SAMPLED AT BENZENE-CONSUMPTION FACILITIES Location S. Charleston, WV Freeport, TX La Porta, TX Bound Brook, NJ Fords, NJ Geismar, LA Plaquemine, LA Company Union Carbide Dow Dupont American Cyanamid Tenneco * Rubicon * Georgia Pacific Number of Samples 3 3 '3 1 1 6 11 Average Sampling Time (min) 100 100 110 44 44 740 660 Average Benzene Concentration (ppb) 34 14 0.8 2.8 0.9 0.6 0.9 •K Samples taken in the vicinity of industrial complexes that have known benzene-consumption facilities. Source: RTI (1977). To assess the ambient benzene concentrations in the vicinity of chemical manufacturing facilities, two factors must be estimated: benzene emission rates at each location; and atmospheric dispersion of benzene in the vicinity of the plants. The emission rates can be estimated if the emission factors and total production are available. Table III-4 gives the emission factors used in the analysis and emission characterization. The emission factors were selected to represent aver- ages. Because little is known about benzene emissions from chemical manufacturing facilities, these emission factors are considered order- of-magnitude estimates. Maleic anhydride and aniline have the highest emission factors related to the specific manufacturing processes and reaction kinetics of each compound. 22 ------- Table III-3 MAJOR CHEMICAL COMPOUNDS OTHER THAN BENZENE EMITTED FROM CHEMICAL MANUFACTURING FACILITIES Process Reference Compound Aniline Chlorobenzene Ethylene/styrene Linear alkylate Maleic anhydride Nitrobenzene Aniline Nitrobenzene Chlorobenzene Dichlorobenzene Trichlorobenzene o-, m-, and p- dichlorobenzene Chlorine Hydrochloric acid Ferric chloride Methane Ethane Ethylene Hydrochloric acid Toluene Ethylbenzene Styrene di- and triethyl benzenes n parafins (CIQ - Cl4 range) Allyl chloride Linear alkyl benzene Hydrochloric acid Olefins Linear alkylate Hydrogen fluoride Maleic acid Formaldehyde Formic acid Acjid aldehyde Xylene Nitrobenzene Dinitrophenol Other dinitro and trinitro compounds 1. Weber, personal communication, 1978. 2. Beck, personal communication, 1978. 3. Mascone, personal communication, 1978. 4. Schumaker, personal communication, 1978. 23 ------- Table III-4 EMISSION FACTORS AND CHARACTERIZATIONS FOR BENZENE-CONSUMPTION PLANTS Chemical Aniline b Cumene a Cyclohexane Detergent alkylate (linear and branched) Dichlorobenzene (p- and o-)b Ethylbenzene Maleic anhydride Monochlorobenzene Nitrobenzene Phenol b Styrene Emission Factor (10~3 kg of benzene/kg of product) 23.60 0.25 2.80 2.20 8.60 0.62 96.70 3.50 7.00 1.00 1.50 Emission Characterization Fugitive Fugitive Fugitive Fugitive Chlorinator, PDCD recovery system Scrubber-vent Product recovery scrubber Unknown Point absorber Unknown Collection vent, emergency vent SRI estimates. PEDCo estimates. 24 ------- * The atmospheric dispersion of benzene is more difficult to assess. Simply, source characteristics (e.g., stack dimensions) and meteorological conditions greatly influence the dispersion of benzene in the vicinity of the plants. Youngblood (1977a, 1978) made rough dispersion estimates from very limited data on source characteristics. He classified the processes according to three source categories: A—ground-level point source (effective stack height, 0 m); B—building source (effective stack height, 10 m); and C—elevated point source (effective stack height, 20 m). Emission rates were then calculated for each process by assuming a maximum production rate. Ambient ground-level concentrations were derived manually from Turner's workbook. One-hour worst-case concentra- tions were derived with the following meteorological conditions assumed: wind speed, 4 m/s; stability class, neutral (Pasquill Gifford "D"). For source category B, the results from Turner's workbook were adjusted to account for the initial dispersion of the pollutant in the building cavity. The one-hour estimates were then converted to 8-hour worst- case estimates (by multiplying by 0.5). The results of the dispersion modeling by Youngblood are given in Table III-5. B. Methodology Each chemical manufacturing plant has different production rates, chemical processes, geographic locations, pollution control technology, and meteorological conditions. Thus, detailed dispersion calculations are impractical, given the scope of the study. A simple method of assessment was therefore developed to allow for comparative analysis. Variations in geographic locations and meteorological conditions were not considered in the analysis. The results are not precise: rather, they provide a reasonable estimate of atmospheric benzene concentrations. * Battelle-Columbus has monitored benzene concentrations in the vicinity of chemical manufacturing facilities. These data are now in draft form and should be available in the near future. 25 ------- Table III-5 ROUGH ESTIMATES OF AMBIENT GROUND-LEVEL BENZENE CONCENTRATIONS (8-HOUR AVERAGE)' K) ON Source Maleic anhydride Styrene Phenol from cumene Benzene Cumene Phenol from benzene Nitrobenzene Ethyl benzene Phenol from toluene Chlorobenzene o- dichlorobenzene p-dichlorobenzene Emission Rate (R/s) 139.0 7.49 10.8 0.179 2.34 0.0691 31.20 16.60 2.42 15.10 3.60 6.20 Concentration (pg/m ) Source Category C A B C A B A B A B C A B C A B A B A B C A B C A B C 150 m 700 3800 850 54 90 20 1200 260 35 8 <1 16000 3500 160 8500 1900 1200 270 7700 1700 76 1800 400 18 3200 700 31 300 m 5000 1100 460 390 26 11 340 140 10 4 2 4500 1900 1100 2400 1000 350 150 2200 940 540 500 220 130 900 380 220 450 m 5000 530 290 390 13 7 170 91 5 3 2 2200 1200 1100 1200 650 170 94 1100 590 540 250 140 130 440 240 220 at Given Distance 600 m 3900 330 210 300 8 5 100 66 3 2 2 1400 870 870 730 460 110 68 660 420 420 160 100 100 270 180 170 750 m 2900 220 160 230 5 4 70 49 2 1 1 940 650 650 500 350 73 51 453 320 320 110 75 75 190 130 130 1600 m 1100 68 55 89 2 1 21 17 1 <1 <1 280 230 250 150 120 21 17 140 110 120 32 26 28 39 46 49 This is a worst-case estimate. It may be multiplied by 0.04 to give rough estimates of annual average concentrations. Key to Source Categories: A—ground-level point source: B—building source; C—elevated point source. Source: Youngblood, 1977a. ------- A single dispersion curve was constructed and applied to all chemical manufacturing facilities, based on their emission rates. The derivation of this methodology is discussed below. As shown in Table III-5, ambient benzene concentrations in the vicinity of chemical manufacturing plants vary significantly in relation to the characteristics of the emission sources. Exhaust gas temperature, which is important in determining near-source concentrations, was not considered. Because of the generally high concentrations estimated at 1.6 km (the maximum distance modeled in that analysis), Youngblood (1977b, 1978) extended his model calculations to a distance of 20 km with an emission rate of 100 g/s for each source category (see Table III-6). The results of Youngblood's analysis are shown in Figure III-2. The ground-level (A) and building (B) sources are highest near the plant and decrease rapidly with distance. The elevated point source (C), however, shows low initial concentrations that increase to a peak followed by a decline. Although the differences due to source category are considerable at 150 m, the differences decrease rapidly with distance. Even as close as 300 m, the differences are within the range of uncertainty normally associated with dispersion calculations. In addition, distances less than 300 m are likely to be within the plant perimeter or to have low population densities. A single dispersion curve (Curve M in Figure III-2) was therefore developed to represent all three source categories, as suggested by Youngblood (1977b). This curve was derived by averaging the high and low values of the three emission source categories at each calculated distance. The resulting concentrations estimated by this method are shown in Table III-7. 27 ------- N) oo Table III-6 ROUGH ESTIMATES OF AMBIENT GROUND-LEVEL BENZENE CONCENTRATIONS (8-HOUR-AVERAGE)* PER 100 g/s EMISSION RATE Source Category 0.15 km A 51,000 B 11,000 C 510 Concentrations 0.3 km 14,000 6,100 3,500 0.45 km 7,000 3,800 3,500 0.6 km 4,500 2,800 2,800 0.75 km 3,000 2,100 2,100 (yg/m ) 1.6 km 900 740 800 2.5 km 440 370 410 4.0 km 220 220 220 6.0 km 120 120 120 9.0 km 62 62 62 14.0 km 34 34 34 20.0 km 20 20 20 To give rough estimates of annual average concentrations, multiply by 0.04; to convert to ppb, divide by 3.2. Source: Youngblood (1977b, 1978). ------- 10s n a. V) O GC UJ O O o uj z UJ N UJ CD 10' 10 TT / / / / / c A • GROUND LEVEL SOURCE B • BUILDING SOURCE C - ELEVATED SOURCE M - AVERAGE OF CURVES A, B, AND C 0.1 100 1.0 10 DISTANCE FROM SOURCE - km 'Baud on an emtolon rate of 100 gf* Source: After Youngbtood, (1977b) FIGURE III-2. DISPERSION MODELING RESULTS FOR EACH TYPE OF SOURCE CATEGORY' 29 ------- Table III- 7 * ESTIMATES OF 8-HOUR WORST CASE BENZENE CONCENTRATIONS BASED ON AVERAGE OF THREE EMISSION SOURCE CATEGORIES 3 t Distance (km) Concentration (yg/m ) 0.30 8800 0.45 5200 0.6 3600 0.75 2600 1.6 820 2.5 400 4.0 220 6.0 120 9.0 62 14.0 34 20.0 20 * To convert to annual average estimates, multiply concentrations by 0.04. To convert to ppb, divide concentrations by 3.2. Source: Youngblood (1977b, 1978). Regression analysis was used to develop an equation to characterize the single dispersion curve (Curve M). Equation (3.1) was derived from that analysis: C = 1648 D'1'48 (3.1) 3 where, C is the 8-hour worst-case benzene concentration in yg/m , and D is the distance from the source in km. Because Equation (3.1) is only valid for an emission rate of 100 g/s, a normalized equation is given as follows: C = 16.48 E D~1-48 (3.2) where, E in g/s, is the emission rate for the location of interest. 3. 30 ------- The annual average concentration can be estimated by including a multiplier of 0.04 in the equation. Thus, the equation becomes: C = 0.659 E D~1<48 (3.3) a In this study, the ranges of benzene concentrations that follow and that apply to all sources have been established for the sake of uni- formity: 0.1 - 1.0 ppb 1.1 - 4.0 ppb 4.1 - 10.0 ppb > 10.0 ppb A computer program was developed to estimate the people exposed to concentrations within each range at each location. Equation (3.3) was rearranged as follows to determine the distance at which the specified concentrations are found: / E \ 0.6757 D = 0.754 -r*- (3.4) \ *• I where, C. is the specified annual average concentration (i.e., 0.1, 1.0, 1 3 4.0, and so on; input data, however, are in ug/m ); D. is the distance in kilometers at which the specified concentration is found; and E is a the emission rate in grams per second at that location. The population residing within a circle of radius D. was then estimated by the following equation: P± = d TT D^ (3.5) where, d is the city or state population density, and P. is the popu- lation exposed to concentration C or greater. 31 ------- The main assumptions in this analysis are that: The benzene source is in the center of the city (if the city has a population greater than 25,000). The maximum allowable radius is 20 km. The population density is uniform over the exposed area. When a city has more than one plant, the plants are colocated, and their corresponding emission rates are summed. If the city has a population of less than 25,000, state density is used. To accommodate these assumptions, the following steps were included in the computer program. The radius of each city was determined by Equation (3.6): / \ 1/2 (3.6) where, D is the estimated radius of the city; P is the population of the city (1970 Bureau of Census data) ; and d is the average city density (1970 Bureau of Census data available for cities of population greater than 25,000). When D. calculated from Equation (3.4) is greater than D , or when no city density is available, Equation (3.7) is substituted for Equation (3.5) to calculate the exposed population on the basis of state density. Pi = Pc+ ds U (Di - Dc> (3'7) where, d is average state population density; D. is the distance at which S 1 concentrations C. is found; D is the radius of the city calculated in Equation (3.6); and P. is the population exposed to concentration C or greater. P and D equal 0 when no city density is available. Because the dispersion modeling results are unverified at distances greater than 20 km from the source location, the computer program auto- matically cut off calculations when (1) a distance of 20 km was attained and calculated the concentration (C.) at 20 km, or when (2) the estimated benzene concentration dropped below 0.1 ppb. 32 ------- The cumulative population totals resulting at distance D. were then automatically subtracted from those at distance D. .. , and the total population within each range of concentrations was printed out. For example, for range 0.1 to 1.0 ppb, the program subtracted P _ (a smaller number) from P (a larger number)- In other words, P is the popu- U • -L U • X lation exposed to concentrations of 0.1 ppb or greater; P.. n is the total population exposed to concentrations of 1.0 ppb or greater. By subtracting the two values, the total population exposed to concentrations between 0.1 and 1.0 ppb is determined. For locations with fewer than three chemical manufacturing facilities, 2 an area of 0.5 km (a circular area with a radius of 400 m) was assumed to be within the plant boundary. No exposed population was estimated within this area. For locations with three or more facilities, an area 2 of 0.8 km (a circular area with a radius of 500 m) was assumed to be within the plant boundary. Emission rates were estimated for each plant, based on the production estimates contained in Table III-l and the emission factors in Table III-4. Because actual production data are unobtainable, capacity production and 24-hour (365 days) operation were assumed. Appendix B, Table B-l, lists the estimated emission rates for each chemical manufacturing facility. The emissions of benzene from chemical manufacturing facilities were assumed to be the sole contributors of benzene to the atmosphere in the vicinity of the facility. C. Exposures Ambient benzene concentrations and the exposed population for each source location were estimated, based on the methodology described above. Table B-2 in Appendix B presents the results of this analysis for each facility location. Table III-8 presents the estimated population exposed to specified levels of atmospheric benzene for each state. More than 7 million people are exposed to annual average benzene concentrations of 0.1 ppb or greater. The largest number of those exposed is found in Pennsylvania, Texas, and 33 ------- Table III-8 ESTIMATED POPULATION EXPOSED TO BENZENE FROM CHEMICAL MANUFACTURING FACILITIES, BY STATE * Population Exposed to Benzene (ppb) State 0.1-1.0 1.1-4.0 4.1-10.0 > 10.0 Alabama California Delaware Georgia Illinois Kansas Kentucky Louisiana Maryland Massachusetts Michigan Mississippi Missouri Nevada New Jersey New York Ohio Pennsylvania Texas Washington West Virginia Puerto Rico 20,000 110,000 20,000 7,000 180,000 4,000 20,000 140,000 500,000 3,000 70,000 20,000 20,000 10,000 1,100,000 180,000 3,000 2,200,000 1,500,000 1,000 110,000 200,000 500 4,400 1,500 200 86,000 80 - 42,000 15,000 - 26,000 7,000 400,000 400 110,000 7,000 100 350,000 200,000 - 8,500 22,000 _ 400 200 - 13,000 - - 5,600 1,000 - 3,000 1,000 100,000 - 23,000 - - 40 , 000 32,000 - 630 4,600 _ - - - 1,700 - - 1,100 - - 400 30 50,000 - 8,800 - — 13,000 7,700 - - 80 Total Exposed Populationf 6,000,000 1,000,000 200,000 80,000 A Totals for each state are rounded to two significant figures. Annual average concentrations; to convert to 8-hour worst case, multiply by 25; to convert to yg/m3, multiply by 3.2; a dash (-) signifies that no exposed population was estimated by our method for the annual average concentrations listed. There may be some population exposed to those concentrations for shorter periods of time. 'Totals are rounded to one significant figure. Source: SRI estimates. 34 ------- New Jersey. These three states account for 75% of the total population exposed to benzene from chemical manufacturing facilities. Chemical manufacturing facilities are responsible for all point- source exposures to the general population greater than 4.0 ppb. Because our computer program is limited to estimating exposed population rather than specific concentrations, predicted concentrations must be calculated separately. To provide an upper boundary for our exposure estimates, the predicted dispersion curves for the four largest uncontrolled chemical manufacturing facilities are shown in Figure III-3. The facilities were selected for two reasons: (1) a high benzene emission rate (greater than 50 g/s, see Table B-2, Appendix B); (2) a large exposed population estimated at high concentrations (Reichold Chemicals, Elizabeth, New Jersey). A plant boundary of 450 m from the source was assumed. The highest concentrations are found in the vicinity of the Monsanto maleic anhydride plant in St. Louis. Annual average concentrations are in excess of 10 ppb as far as 2 km from the source. At the plant boundary, the estimated annual average concentration is 96 ppb. For comparison, estimated urban annual average concentrations related to automobile emissions generally range between 1 and 4 ppb. The lowest concentrations of those facilities plotted are found in the vicinity of the Reichold Chemicals maleic anhydride plant in Elizabeth, New Jersey. Those annual average concentrations range from 28 ppb at the plant boundary to 0.1 ppb at 20 km from the source. Short-term high level exposures may also be important in affecting * risk to an individual. Figure III-4 compares annual average with 8-hour worst case concentrations. Note that both facilities show 8-hour worst case concentrations above 1.0 parts per million (ppm) outside the plant boundary, with 1-hour peak levels a factor of 10 higher than the 8-hour concentrations. For the two facilities shown on Figure III-4, the 1-hour * The assumption of a linear dose-response, however, requires that higher concentrations for short periods have no higher risk associated with them. 35 ------- 200 100 _ a a O z LU CJ O O HI z LU N LU CO 10 Monsanto—St. Louis, Missouri: maleic anhydride • -O Monsanto—Texas City. Texas: ethylbenzene, styrene •-—• U.S. Steel—Neville Island, Pennsylvania: maleic anhydride • —* Reichold Chemicals—Elizabeth, New Jersey maleic anhydride I I I I DISTANCE FROM SOURCE - km Assumed ** The four facilities having the largest benzene emissions and/or the largest number of exposed population at high concentrations. Source: SRI estimates based on dispersion modeling. FIGURE III-3. PREDICTED ANNUAL AVERAGE BENZENE CONCENTRATIONS IN THE VICINITY OF SELECTED** CHEMICAL MANUFACTURING FACILITIES 36 ------- 5,000 1,000 100 a: ui o o o ui z ui N UI CD 10.0 1.0 0.1 i r IT MONSANTO-ST. LOUIS, MISSOURI: MALEIC ANHYDRIDE REICHOLD CHEMICALS-ELIZABETH," NEW JERSEY: MALEIC ANHYDRIDE OSHA 8-HOUR STANDARD 8-HOUR —\ WORST CASE \ ^Source: SRI ESTIMATES BASED ON ^^ DISPERSION MODELING \ ANNUAL" AVERAGE \ 0.1 * Assumed 1.0 DISTANCE FROM SOURCE-km 10 30 FIGURE III-4. COMPARISON BETWEEN PREDICTED ANNUAL AVERAGE AND 8-HOUR WORST CASE BENZENE CONCENTRATIONS IN THE VICINITY OF TWO CHEMICAL MANUFACTURING FACILITIES 37 ------- peak concentrations would range from 41,000 to 12,000 ppb (41 to 12 ppm) at the plant boundary to 100 to 25 ppb 20 km from the source. 38 ------- IV COKE OVENS A. Sources In 1975, 57.2 x 10 tons of coke were produced in the United States. The yield of coke from coal, averaging 68.4% in 1975, has remained fairly constant during the past decade (Sheridan, 1976). Coke is produced by 65 plants in the United States (Suta, 1977). The 65 plants, which are listed in Appendix C, consist of an estimated 231 coke-oven batteries containing 13,324 ovens. Their theoretical maximum annual productive capacity is 74.3 x 10 tons. Table IV-1 shows the estimated size and productive capacity in each state. Coke ovens producing benzene as a by-product account for about 5 to 8% of the total benzene production in the United States. About 0.66% by volume benzene, 0.13% toluene, 0.05% xylene, and less than 0.10% of other aromatics have been identified in the coal gas generated from coking operations (Faith et al.,1966). The higher the temperatures in coking operations, the larger the amounts of aromatic hydrocarbons produced, particularly benzene. Reduction in quantities of paraffinic naphthenic (saturated alicyclic) and unsaturated hydrocarbons in the production is observed at high temperatures (Faith et al.j!966; McGannon, 1970). Carbonizing 1 ton of coal in coke ovens to produce blast furnace coke yields 3 to 4 gallons of light oil. The principal constituent of this oil is benzene, which comprises about 60 to 80% of the total composition. This crude light oil is then distilled to produce benzene, toluene, and xylene. The typical amount of benzene recovered from coke-oven gas is 1.85 gal/ton of coal carbonized (U.S. Public Health Service, 1970). The distillation of coal tar is one additional source of benzene production. The amount of benzene produced varies with the coking and recovery processes and the grade of the raw coal. In general, the light 39 ------- Table IV-1 ESTIMATED SIZE AND PRODUCTIVE CAPACITY OF BY-PRODUCT COKE PLANTS IN THE UNITED STATES ON DECEMBER 31, 1975 State Number of Plants* Alabama California Colorado Illinois Indiana Kentucky Maryland Michigan Minnesota Missouri New York Ohio Pennsylvania Tennessee Texas Utah West Virginia Wisconsin Undistributed Total 62 (65)" Included in Undistributed. Colocated plants. Source: Sheridan (1976). Number of Batteries 7 1 1 4 6 (7)* 1 1 3 2 1 3 12 12 (13)* 1 2 1 3 (4)* 1 28 7 4 9 31 2 12 10 5 3 10 35 51 2 3 4 13 2 231 Number of Ovens 1,401 315 206 424 2,108 146 758 561 200 93 648 1,795 3,391 44 140 252 742 100 13,324 Maximum Annual Theoretical Productive Capacity (tons) 6,961,000 1,547,000 1,261,000 2,523,000 11,925,000 1,050,000 3,857,000 3,774,000 784,000 257,000 4,053,000 9,960,000 18,836,000 216,000 839,000 1,300,000 4,878,000 245,000 74,266,000 Coke Production in 1974 (tons) 5,122,000 1,912,000 9,073,000 C1) 3,259,000 <»> 8,842,000 16,318,000 (') (O 3,555,000 12.656.000 60,737,000 ------- oil distilled from coal tar is added to the major portion of light oil recovered from coal gas and refined for its benzene content. Appendix A contains a diagram of a typical coke-oven operation. The basic coke-oven sources of air pollutant emissions include charging and topside emissions, emissions from doors during the coking cycle, waste gas stack emissions, pushing emissions, and quenching emissions, The only benzene concentration data available are occupational exposure data. Table'IV-2 gives the typical benzene concentration ranges per occupation, within a coal-derived benzene recovery plant (NIOSH, 1974). Measurements of benzene in Czechoslovakia coke-oven plants are tabulated in Table IV-3. In the recovery plant, the benzene concentration can 3 reach as high as 145 mg/m . Table IV-2 AMBIENT LEVELS OF BENZENE WITHIN A COAL-DERIVED BENZENE PRODUCTION PLANT 8-hour Time-Weighted Average Range Occupation (ppm) (ppm) Agitator operator 6.0 0.5-20 Benzene loader and loader helper 4.0 0.5-15 Benzene still operator 4.0 1-15 Light oil still operator 2.5 1-15 Naphthalene operator 10 2-30 Analyst 10 4-30 Chemical observer 10 4-50 Foreman 1.5 1-10 Source: Bethlehem Steel Corporation data (NIOSH, 1974) 41 ------- Table IV-3 ATMOSPHERIC BENZENE EMISSION FROM THE COKING AND RECOVERY PLANTS IN CZECHOSLOVAKIA Benzene Concentration 3 Areas yg/m 3 Coke-oven battery 50. - 13 x 10 3 Recovery plant 50. - 145 x 10 2 Tar processing 3 x 10 Source: Masek (1971). Data on benzene concentration in the vicinity of coke-oven and benzene recovery plants are unavailable. In coke-oven operations, the charging of coal is regarded as the potentially largest source of benzene emissions. Many pollutants escape from coke-oven operations in addition to benzene. The major chemical compounds found in coke-oven emissions are identified in Table IV-4. The emissions consist of gases, condensable vapors, and particulate matter, many of which have documented toxic and/ or carcinogenic properties. Therefore, -the population exposed to coke- oven emissions of benzene is similarly exposed to many other chemical compounds. B. Methodology and Exposures To estimate the at-risk population to benzene from coke-oven emissions, the number of people residing around the coke-oven plants and the ambient benzene concentration must be determine. The general methodology discussed in Chapter III was used as the basis for determining exposure levels from coke ovens. Variations in geographic locations, meteorologic conditions and control technology were not considered in the analysis. 42 ------- Table IV-4 PARTIAL LIST OF CONSTITUENTS OF COKE OVEN EMISSIONS POLYNUCLEAR AROMATIC HYDROCARBONS Anthanthrene Anthracene"'" Benzindene^" Benz(a)anthracene' Benz(b)fluoranthene Benzo(ghi)fluoranthene Benzo(j)fluoranthene^ Benzo(k)fluoranthene Benzof luorene"'" Benzo(a)f luorene''" Benzo(b)fluorene Benzo (c) f luorene''" Benzophenanthrene"'" Benzo(ghi)perylene"'" Benzo(a)pyrene* Benzo(e)pyrene Benzoquino line^" Chrysene Coronene^ Dibenz(a,h)anthracene Dibenzo(a,h)pyrene Dihydroanthracene^ Dihydrobenzo (a) f luorene''" Dihydrobenzo (b)f luorene"'" Dihydrobenzo(c)fluorene^ Dihydrobenz (a) anthracene''" Dihydrochrysene"*" Dihydrof luoranthene"'' Dihydrof luorene"'' Dihydrome thy lbenz( a) anthracene"'' Dihy drome thy lbenzo(k and b)f luoranthenes"'' Dihydrome thy Ibenzo (a and e)pyrenes"'" Dihy drome thy Ichrysene"*" Dihydromethyltriphenylene^ Dihydrophenanthrene Dihydropyrene"'" Dihydrotriphenylene^" Dimethy Ibenzo (b) f luoranthene"*" DimethyIbenzo(k)fluoranthene Dimethy Ibenzo (a) pyr ene"*" Dimethy Ichrysene"'" DimethyItriphenylene^ Ethylanthracene"'" Ethylphenanthrene"'" Fluoranthene^" Fluorene^ Fluorene carbonitrile^ Indeno(1,2,3-cd)pyrene Methylanthracene''' Methylbenz (a) anthracene"'" Methy Ibenzo ( a) pyrene''" Me thyIbenzo(ghi)perylene' Methylchrysene''" Me thy If luoranthene"'' Methy If luorene^" Methylphenanthrene^ Methylpyrene''" Methyltriphenylene^ Naphthalenet Octahydroanthracene''' Octahydrof luoranthene''" Octahydrophenanthrene''" Octahydropyrene''" Perylene''" Phenanthrene"'" O-Phenylenepyrene"*" Pyrene"'" Triphenylene"!" POLYNUCLEAR AZA-HETEROCYCLIC COMPOUNDS Acridine1" ^ Benz(a)acridine Benzoquinilinef Dibenz(a,h)acridine' Dibenz(a,j)acridine^ Isoquinilinet QuinolineT 43 ------- Table IV-4 (concluded) AROMATIC AMINES Aniline* B-Naphthylamina ct-Naphthylamine OTHER AROMATIC COMPOUNDS Benzene Pyridine* Mono-, di-, and tri-methylated pyridine* Toluene** Phenol5 Arsenic Beryllium* Cadmium Chromium Cobalt* Xylene ** TRACE ELEMENTS Iron Lead* Nickel Selenium OTHER CASES Ammonia5 Carbon disulfide5 Carbon monoxide5 Hydrogen cyanide5 Acroleint Aliphatic aldehydes' Hydrogen sulfide Methane 5 Nitric Oxide** § Sulfur dioxide MISCELLANEOUS ALIPHATIC COMPOUNDS Formaldehyde* MethaneT § Key to sources: * Kornreich (1976) t Lao, et al. (1975) f Mabey (1977) § Smith (1971) ** White (1972) 44 ------- Crude dispersion modeling was conducted by Youngblood of EPA (1977c, 1978). Coke-oven operations usually cover a large area and benzene emissions are distributed widely throughout. Consequently, the point source model used by Youngblood to estimate downwind concentrations resulting from chemical manufacturing emissions is not applicable. To account for the emissions distributed over a large area, Youngblood used the PAL (Point, Area, and Line Source) Dispersion Model (Burner et al., 1975) that results in lower ambient impact for a given emission rate. The benzene emissions were assumed to occur primarily from oven leaks. The model assumptions were as follows: square plant area; uniform distribution of emissions throughout the area; effective stack height, 10 m; wind speed, 4 m/s; stability class, neutral (Pasquill Gifford "D"). Maximum, one-hour-average concentrations at selected downwind distances for a given emission rate of 100 g/s were obtained from PAL. These were divided by two to represent maximum eight-hour-averages. These are shown in Table IV-5. 2 The plant size most applicable to coke-oven operations is 0.25 km (500 m on a side). The curve corresponding to this plant size is shown in Figure IV-1. An equation was developed through regression analysis to characterize this curve: C - 403 D~°'91 (4.1) 3 where C is the 8-hour worst case benzene concentration in yg/m ; and D is the distance from the source in km. Equation (4.1) was then normalized to annual average conditions and to individual emission rates (the Youngblood model was based on an emission rate of 100 g/s): C = 0.16 E D~°'91 (4.2) In this report, "crude" is used to mean approximate and extrapolatable. 45 ------- 1000 P) • z o UJ u o o UJ N UJ CO 100 10 TTTT 1 I I 1 I I I I Source: After Youngblood (1977c) I I I I I I 1 I I I I I I I I I I 0.1 1.0 10 DISTANCE FROM SOURCE - km * Based on an emission rate of 100 g/s. This is much higher than most coke-oven operations which usually have emission rates less than 10 g/s. FIGURE IV-1. DISPERSION MODELING RESULTS FOR COKE-OVEN OPERATIONS* 100 ------- Table IV-5 ROUGH ESTIMATES OF 8-HOUR WORST CASE BENZENE CONCENTRATIONS PER 100 g/s EMISSION RATE USING THE PAL DISPERSION MODEL Distance From Source Area (km) 0.3 0.45 0.60 0.75 1.6 2.5 4.0 6.0 9.0 14.0 20.0 3 (Concentration yg/m ] 0.01 km2 5,000 3,850 2,850 2,150 800 405 205 110 60 33 20 .06 km2 2,000 1,700 1,450 1,250 600 360 190 110 60 32 20 0.25 km2 900 750 650 595 390 270 165 100 55 32 19 * 1 for Given Plant Area 1 km2 365 325 290 260 190 150 110 80 50 29 18 4 km 145 130 120 110 85 70 50 45 34 23 16 9 km2 80 75 70 65 50 43 35 29 23 18 13 25 km2 39 37 34 33 27 23 20 17 14 11 9 To give rough estimates of annual average concentrations multiply by 0.04; to convert to ppb, divide concentrations by 3.2 Source: Youngblood (1977c). ------- To estimate the number of people exposed to benzene concentrations within each range at each location, Equation (4.2) is rearranged as follows to determine the distance at which the specified concentrations are found: D. = 0.133 - | (4.3) where C. is the specified annual average concentrations (i.e., 0.1, 1.0, 1 3 4.0, and so on; input data, however, are in yg/m ); D. is the distance in km at which the specified concentration is found; and E is the emission SL rate in g/s at that location. Detailed population estimates for as far as 15 km from each location were available from another SRI study (Suta, 1977). Consequently, once distances (D.) were determined, the population exposed to benzene con- centrations within each range was easily determined. Geographic coordi- nates for most of the coke plants were obtained from the U.S. EPA-NEDS data system. The remainder were obtained from consulting maps or by telephone conversation. The population residing within a 15-km radius about each coke plant was calculated by use of the Urban Decisions Systems, Inc., Area Scan Report. This computer data system contains the 1970 census data in the smallest area available (city blocks and census enumeration districts). Emission rates for each coke-oven operation were estimated by basing them on the capacity and the emission factor of 0.06 Ib benzene/ton of * coal obtained from EPA document AP-42 (EPA, 1976). Because actual pro- duction data are unobtainable, capacity production and 24-hour (365 days) operation were assumed. Appendix C lists the estimated emission rates Three plants were colocated and their corresponding emission rates were * Estimated by multiplying the hydrocarbon emission factor (4.2 Ib/ton of coal) by the fraction of benzene in the total hydrocarbon emissions (0.0132). 48 ------- summed. The emissions of benzene from the coke plants were assumed to be the sole contributors of benzene to the atmosphere in the vicinity of the oven. Table IV-6 summarizes people exposed to various annual average benzene concentrations by state. Approximately 300,000 people are exposed to annual average concentrations greater than 0.1 ppb (8-hour worst case concentration greater than 2.5 ppb). Pennsylvania has the highest number of exposed population (43% of the total), followed by Indiana (19%) and Michigan (12%). 49 ------- Table IV-6 ESTIMATED POPULATION EXPOSED TO BENZENE FROM COKE OVENS, BY STATE Population Exposed to Benzene (ppb) State 0.1 - 1.0 Alabama 8,700 California 1,400 Colorado Illinois 830 Indiana 58,000 Kentucky 550 Maryland 19,000 Michigan 36,000 Minnesota - Missouri - New York 24,000 Ohio 17,000 Pennsylvania 130,000 Tennessee Texas Utah 20 West Virginia 3 Wisconsin - Total* 300,000 Totals for each state are rounded to two significant figures; a dash (-) indicates that no exposed population was estimated by our method for the annual average con- centrations listed. There may be some popu- lation exposed to those concentrations for shorter periods of time. Annual average concentrations; to convert to 8-hour worst case, multiply by 25; to convert to yg/m3, multiply by 3.2. "Total is rounded to one significant figure. Source: SRI estimates. 50 ------- V PETROLEUM REFINERIES A. Sources Petroleum refineries appear to be a significant source of atmos- pheric benzene emissions, with more than 250 operating in 39 states. Benzene is a constituent in crude oil and gasoline, and is produced as a by-product of the refining process. Benzene emissions from a refinery include: (1) process emissions from .light and heavy naphtha streams from the crude unit; fluid catalytic cracking units; hydrocracking units; gasoline treating units, and pumps, flanges, and other sources of fugitive emissions; and (2) nonprocess emissions from wastewater treat- ment facilities, heaters and boilers, and facilities for storage and handling of benzene and gasoline (PEDCO., 1977). Benzene produced from catalytic reforming extraction by petroleum refineries accounted for 50% of the benzene supply in the United States in 1976 (SRI estimates). Because the average distribution of aromatics in reformate is 10% benzene, 40% toluene, and 50% xylene, toluene dealkylatibn processes are being used more frequently to increase the benzene fraction. (Faith et al., 1966). Toluene dealkylation to produce benzene currently accounts for 27% of the benzene supply in the United States (SRI estimates). This process is most common in petrochemical complexes, rather than in the petroleum refineries. Table V-l lists the petroleum refineries in each state that extracts aromatics from the reformate produced in catalytic reforming. Texas and Louisana account for 84% of the total production of benzene, toluene, and xylene. The composition of crude oil varies widely, but commonly contains about 0.15% benzene by volume (Dickerman et al., 1975). Consequently, benzene is emitted during the refining process. We have assumed that refineries with catalytic reforming of benzene (34 out of 266 refineries) have larger benzene emissions than those without catalytic reforming because of the processing and handling involved. Many of the refineries 51 ------- with catalytic reforming of benzene use it captively in the production of a wide variety of chemicals; others sell some or all of the benzene produced to chemical manufacturers. Table V-l * PETROLEUM REFINERIES PRODUCING AROMATICS, BY STATE State California Illinois Kansas Kentucky Louisiana Mississippi New York Oklahoma Pennsylvania Texas Total Number of Plants 3 2 1 1 3 1 1 1 3 li 34 Quantity (bbl/stream day) 5,990 6,700 1,400 4,000 19,100 6,000 3,000 2,000 9,700 122,525 180,415 Total quantity of benzene, toluene, and xylene produced. Source: Oil & Gas Journal (May 28, 1977) Monitoring data from one refinery producing benzene as a by-product are shown in Figure V-l. Even though all samples were collected during the same day, the measurements varied widely. Furthermore, the limited nature of these data makes extrapolation unreliable. The American Petroleum Institute. (API) conducted atmospheric moni^- toring for benzene in the vicinity of petroleum refineries in summer 1977 (draft report, 1977, cited in PEDCo, 1978). Four refineries in different geographic locations were sampled for 24 hours. Quality 52 ------- 100 z o DC 5 10 o o o 111 z UJ N UJ CO I I I I 1 I I I I I I I I I L I 0.1 1.0 10 DISTANCE FROM SOURCE - km Collected in activated charcoal tubes and analyzed by gn chromatograph with a flame tonlzatlon detector. Detection limit was approximately 0.1 fig of benzene/100 mg charcoal. Source: EPA, 1977 FIGURE V-1. MONITORING DATA* FOR GULF ALLIANCE REFINERY, BELLE CHASSE, LOUISIANA 53 ------- Table V-2 ATMOSPHERIC BENZENE CONCENTRATIONS AT DISTANCES GREATER THAN 1 KM FROM PERIMETER OF PETROLEUM REFINERIES Average Benzene Concentration Geographic Location of Refinery Mid-Atlantic Pacific Northwest Midwest Gulf Coast No. of Samples* 3 1 7 3 (ppb) at > 1 km from Perimeter 3 2 <1 5 24-hour samples. Source: API (1977), as cited in PEDCo (1978). ------- control information is unavailable for these measurements. Concentra- tions beyond 1 km from the plant perimeter ranged from less than 1 ppb at one location to 5 ppb at another. Table V-2 summarizes this information. Radian Corporation conducted atmospheric benzene monitoring for Shell Oil Company in the vicinity of the Shell Oil petrochemical refinery in Deer Park, Texas, for 6 consecutive days in December, 1977 (Radian, 1978). Under varying meteorological conditions, the sample site 400 m from the plant perimeter showed 24-hour concentrations ranging from 2 to 13 ppb, with a 6-day average of 7 ppb. Complete quality control information is unavailable for these data. At the request of EPA, Research Triangle Institute reanalyzed the results of previously collected ambient monitoring data stored on computer tape to determine benzene concentrations (Research Triangle Institute, 1977). Table V-3 indicates the results for eleven samples collected in the vicinity of petroleum refineries. All sampling occurred within or near the plant perimeter except for the St. Louis sample which was taken 3.2 km (2 miles) east of the Shell refinery. Table V-3 RESULTS OF AMBIENT BENZENE MONITORING IN THE VICINITY OF PETROLEUM REFINERIES Location Deer Park, Pasadena, TX El Segundo, CA St. Louis, MO Facility Shell, Tenneco Chevron Shell Number of Samples Average Benzene Concentration (ppb) 9 1 1 3.4 258 72 Source: Research Triangle Institute, 1977. 55 ------- The results of atmospheric monitoring in the vicinity of petroleum refineries give widely differing estimates of ambient benzene concentrations. Differences in analytical techniques, sampling periods, meteorologic conditions, and plant operations probably affected the estimated concen- trations significantly. Four states have 60% of the refining capacity in the United States: California (14%), Illinois (7%), Louisiana (13%), and Texas (26%). Pennsylvania (5%) and New Jersey (4%) bring the total to 69%. Thus, 15% of the states (6 out of 39 states) with petroleum refineries account for 69% of the refining capacity. B. Methodology 1. Refining of Crude Oil The general methodology discussed in Chapter III was used as the basis for determining exposure levels from petroleum refineries. Youngblood of EPA conducted dispersion modeling (1977c, 1978) to charac- terize benzene emissions from petroleum refineries. The results were then applied to each refinery by computer program to estimate the exposed population. Emissions are highly variable, depending on the size and age of the plant and on the control technology employed; however, because specific emission factors were unavailable, general averages were used. Because actual production data are unobtainable, capacity production and 24-hour (365 days) operation were assumed. Variations in geographic location and meteorological conditions were not considered. Estimates of refinery emission factors were based on average hydrocarbon emissions and the percent of the total hydrocarbon emissions attributed to benzene. Evaluations of available information and dis- cussions with EPA (Radian Corporation, 1975; Hustvedt, personal communi- cation, June 1977a) resulted in the selection of the following factors: Total hydrocarbon emissions from petroleum refineries = 920 lb/1,000 bbl Estimated percentage of hydrocarbon emissions attributed to benzene from refineries without catalytic reforming = 0.5 56 ------- Estimated percentage of hydrocarbon emission attributed to benzene from refineries with catalytic reforming = 1*0. These emissions result from gasoline storage losses («50%) and from leaks and stacks (s50%). Table V-4 presents the calculations of emission factors from the two types of petroleum refineries identified. The listing of U.S. petroleum refineries, shown in Appendix D, was obtained from the Annual Refining Survey published in the Oil & Gas Journal (March 28, 1977). This listing includes a breakdown of refineries that extract benzene, toluene and xylene from the reformate as well as the plant capacities. The emission rate in g/s for each plant was estimated, based on the plant capacity and the emission factor. The emission rate for each plant is shown in Appendix D. Table V-4 CALCULATION OF EMISSION FACTORS FOR PETROLEUM REFINERIES Refineries with catalytic reforming: 0.92 Ib/bbl ( uul?" "'"I"-. ) x 0.01 ( £«""'• ) x 103 g/kg ., , 3 \carbon emissions/ \ benzene / ° ° = 26 g/m 0.159 m3/bbl x 2.2 Ib/kg Refineries without catalytic reforming: 0.92 Ib/bbl f*01?1 hyd™-. ) x 0.005(Percent) x 103 g/kg .. , 3 \ carbon emissions / \ benzene / ° = 13 g/m 0.159 m3/bbl x 2.2 Ib/kg Because petroleum refineries are large and benzene emissions are distributed widely throughout the plant area, Youngblood used the PAL (Point, Area, Line Source) Dispersion Model (Turner et al.) to estimate approximate downwind concentrations. The modeling assumptions and procedure were the same as those described for coke ovens (Chapter IV), Table IV-6 applies to petroleum refineries as well as to coking plants. 57 ------- Three of the size categories are applicable to petroleum refineries (Hustvedt, personal communication, 1977b): 2 Plant Area (km ) Capacity (bbl/day) 0.25 < 35,000 1.00 35,000 - 200,000 4.00 >200,000 Figure V-2 shows the curves corresponding to the three plant sizes. Because the differences between the curves are within the range of uncertainty associated with dispersion analysis, the middle curve 2 (1.0 km ) was used to represent the dispersion characteristics of all refineries at the suggestion of Youngblood (personal communication, August 1977)- The computer program discussed in Chapter III was applied to petroleum refineries by substituting a new equation developed through 2 regression analysis to characterize the 1.0-km curve. This equation can be written as follows: C = 200 D~°'51 (5.1) where, C is the 8-hour worst-case benzene concentration in yg/m ; and D is the distance from the source in km. Equation (5.1) was then normalized to annual average conditions and individual emission rates (the Youngblood model was based on an emission rate of 100 g/s): C = 0.08 E D~°'51 (5.2) 3. where, E is the emission rate in g/s for the location of interest. 3. 58 ------- 1000 1 I I I I I I 1 I I I 1 I I I PLANT AREA (km2) 0.25 Oi •at cc UJ u o u Ul N 100 iIIT r L_ 10 I I I I I I I 0.1 1.0 10 100 DISTANCE FROM SOURCE - km Based on an emission rate of 100 g/s. This is much higher than most petroleum refineries which usually have emission rates less than 10 g/s. Source: After Youngblood (1977c) FIGURE V-2. DISPERSION MODELING RESULTS FOR THREE SIZE CATEGORIES OF PETROLEUM REFINERIES" ------- To estimate the people exposed to benzene concentrations within each range at each location, Equation (5.2) is rearranged as -follows to determine the distance at which the specified concentrations are found: D. = 0.007 -TT- 1 (5-3> where, C. is the specified concentration (i.e., 0.1, 1.0, 4.0, and so on; 1 3 input data, however are in ug/m ); and D. is the distance in km at which the specified concentration is found. The remaining steps in the method- ology are discussed in Chapter III. If more than one refinery was located in a particular city: we assumed that the refineries were co-located, and we summed their emission rates. Although several cities had three or more refineries, it is also true that few people generally live near such complexes. Thus, with this method, the exposed population is minimized, whereas the exposure level is maximized for a particular city. For locations with fewer than three refineries, an area of 2 0.8 km (circle with a radius of 500 m) was assumed to be within the plant boundary. No exposed population was estimated within this area. 2 For locations with three or more refineries, an area of 1.0 km (circle with a radius of 600 m) was assumed to be within plant boundaries. Benzene emissions from petroleum refineries were assumed to \ be the sole contributors of benzene to the atmosphere in the vicinity of the refinery. 2. Storage and Transfer of Pure Benzene Benzene is produced as a salable by-product by 36 petroleum refineries. The benzene emission rates associated with storing, handling, and distributing pure benzene are much higher than those associated with storing, handling, and distributing gasoline. Because the calculation of emission rates for petroleum refineries did not include emissions from storage and transfer of pure benzene, the additional benzene emissions 60 ------- were calculated for the 36 refineries and added to the emission rates calculated in the previous section. A discussion of the methodology and assumptions used follows. The emission factors for storage and transfer of pure benzene are shown in Table V-5. Information on the type of storage and transfer operation in use at 12 refineries was made available in summary form by the Chemical and Petroleum branch of EPA's Office of Air Quality Plan- ning and Standards from the Section 114 letter sent out in 1977 (Brothers, personal communication, 1978). That information was used along with the following assumptions in determining the benzene emission rate at each refinery: Table V-5 SUMMARY OF EMISSION FACTORS FOR PURE BENZENE STORAGE AND TRANSFER - Facility Control Type Benzene Emission Factor (g/gal) * Reference Benzene storage Benzene storage Benzene transfer Inland barge Tank truck Rail car Uncontrolled 3.0 Internal floating roof, vapor recovery 0.3 Uncontrolled 0.76 Uncontrolled 1.8 Uncontrolled 1.8 3 1 1 Key to references: 1. Durham, personal communication, 1978. 2. Burr, personal communication, 1978. 3. Markwordt, personal communication, 1978. 61 ------- Benzene production is about 82% of capacity (SRI estimates). If all of the benzene produced was used captively, only storage emissions were assumed. If some portion of the benzene produced was known to be used captively, loading emissions were only attributed to the percentage sold to outside customers. If no information was available concerning the type of benzene transfer operation at a refinery, tank trucks and/or rail cars were assumed for all benzene transfers. If information was available, percentages of the total production were assigned to barge or rail/ truck transfer, and .the associated emission was determined. If no information was available concerning the type of storage at a particular refinery, uncontrolled storage was assumed. The average benzene storage tank was assumed to hold 55,000 barrels (Durham, personal communication, 1978). Every tank was assumed to have a 26-day retention time (Burr, personal communication, 1978). Truck and rail loading of benzene takes place in a centralized location that is at a distance from the storage tanks. Barges and tankers are loaded at another location. Therefore, emissions from loading operations derive from one or two locations distinct from the storage tank area. Because storage and transfer emissions are distributed over a large area, they are considered to be area-wide emissions and can thus be added to the refinery emission rate calculated in the previous section. Equation (5.3) is then applied to determine the exposed population. Table D-l in Appendix D lists each petroleum refinery and the estimated emission rates. C. Exposures The population exposed to atmospheric benzene from petroleum re- fineries by plant location is shown in Appendix D. A state summary of annual average concentrations and exposed population is shown in Table V-6. More than 5 million people are exposed to benzene from petroleum refineries. Virtually all of the estimated population is exposed to annual average concentrations between 0.1 and 1.0 ppb. In only two 62 ------- Table V-6 ESTIMATED POPULATION EXPOSED TO BENZENE FROM PETROLEUM REFINERIES, BY STATE State Alabama Alaska Arizona Arkansas California Colorado Delaware Florida Georgia Hawaii Illinois Indiana Kansas Kentucky Louisiana Maryland Michigan Minnesota Mississippi Missouri Population Exposed 0.1-1.0 (ppb)t State 230,000 100 110,000 4,300 280 6,000 240,000 6,000 10 30,000 Montana Nebraska New Hampshire New Jersey New Mexico New York North Dakota Ohio Oklahoma Oregon Pennsylvania Tennessee Texas Utah Virginia Washington West Virginia Wisconsin Wyoming Population Exposed 0.1-1.0 1.1-4.0 (ppb)t (ppb)t 51,000 20,000 300,000 8,100 2,000,000 1,500,000 80 2,600 Total* 5,000,000 3,000 Totals for each state are rounded to two significant figures; a dash (-) indicates that no exposed population was estimated by our method for the annual average concentrations listed. There may be some population exposed to those concentrations for shorter periods of time. Annual average concentrations; to convert to 8-hour worst case, multiply by 25; to convert to yg/m3, multiply by 3.2. ^Totals are rounded to one significant figure. Source: SRI estimates. 63 ------- locations, Port Arthur and Corpus Christ!, Texas, are people exposed to annual average concentrations higher than 1.0 ppb. Pennsylvania, which is fifth in number of petroleum refineries, has the highest exposed population with 2,000,000; Texas is second with 1,500,000. Five states account for almost 90% of the total population exposed to benzene from petroleum refining. 64 ------- VI SOLVENT OPERATIONS A. Sources Little is known about benzene used in solvent operations. Recent publications evaluating benzene in the workplace have identified industries in which benzene may be used as a solvent, but the studies were unable to quantify actual volumes of use (Arthur D. Little, Inc., 1977; PEDCo, 1977; Mitre, 1976). The Occupational Safety and Health Administration (OSHA) is currently evaluating industries for benzene hazards under their newly promulgated standards. In addition, a detailed study of market input and output of benzene in solvent operations is currently being conducted for the Office of Toxic Substances. Table VI-1 lists major industries that OSHA is investigating to determine whether benzene is used as a solvent in their operations. Some indication of the maximum possible volume .of benzene used in solvent operations can be obtained by evaluating benzene consumption data for the United States. More than 95% of all benzene used as a raw material is consumed by seven chemical manufacturing processes (see 8 8 Chapter III). Only 2.8% (3.05 x 10 Ib [1.39 x 10 kg]) is consumed by other uses (SRI estimates, 1977). Other uses include benzene for: anthraquinone, benzene hexachloride, benzene sulfonic acid (primarily for phenol), diphenyl, hydroquinine, nitrobenzene (other than that used for aniline), resorcinol, and solvent applications. Because three of the uses (resorcinol, nitrobenzene, and benzene sulfonic acid) account for approximately 50% of the benzene consumed by all other uses, solvent f 6 operations must consume much less than 150 x 10 Ib/yr (68.0 x 10 kg). In fact, many operations have switched to other solvents because of the toxicity hazard associated with benzene. The amount of benzene used by solvent operations is consumed in many, small volume markets (SRI estimates, 1977). 65 ------- Table VI-1 INDUSTRIES AND MANUFACTURED PRODUCTS POSSIBLY USING BENZENE AS A SOLVENT Rubber tires Miscellaneous rubber products Adhesives Gravure printing inks Printing and publishing Trade and industrial paints Paint removers Miscellaneous industrial uses Coated fabrics Synthetic rubber Leather and leather products Floor covering Source: Brinkerhoff, personal communication, 1977. A recent study by Arthur D. Little (ADL) (1977a) identified the manufacture of rubber tires and of miscellaneous rubber products using synthetic rubber and adhesives as possible major sources of occupational exposures. Although industry sources indicate that benzene has been removed from many of the operations within the rubber industry, the ADL study reported that substantial quantities are still being used in the manufacture of synthetic rubbers, production of phenolic antioxidants, polymerization of hydrophilic polymers, and manufacture of rubber adhesives. However, these operations may take place in locations apart from the location where the final product is produced. Limited monitoring data are available. NIOSH is currently conducting a sampling program in the vicinity of solvent operations using benzene (Hardel, personal communication, 1977). Sampling data for three B.F. Goodrich Chemical Company solvent operations were recently submitted 66 ------- to EPA. Figure VI-1 displays the measured benzene concentrations at various sampling sites within 1 km of the source. Benzene concentrations were highly variable, ranging from nondetectable to 720 ppb. (The wide variability probably occurred because the wind was gusty, averaging between 10 and 15 mph throughout the sampling period.) Complete quality control information is unavailable for these data. The potential for environmental exposure to benzene from solvent operations appears to be significant. B. Methodology and Exposure Because of the extremely limited information on operations using benzene as a solvent, amount used, and probable emission factors, any exposure estimates are necessarily .crude. The primary assumption is that only the largest plants will have significant potential for high environmental exposure. The 1972 Census of Manufacturers (Bureau of the Census) was used to determine those operations that have the largest average plant size. Table VI-2 lists the major operations and average number of employees per plant. Five operations that averaged more than 100 employees per plant were selected for further analysis. Table VI-3 lists the number of plants and average number of employees per plant for each of the five operations by state. Georgia and California have the largest number of plants, together comprising 32% of the total. Based on Table VI-3, it can be assumed that the population in the states with the most plants has the greatest risk of benzene exposure from the solvent operations identified. The approximate benzene used for each operation can be roughly estimated by assuming average plant sizes. As discussed in the previous section, it is known that 150 x 10 Ib/yr of benzene (68 x 10 kg/yr) is used for other unidentified uses and that solvent applications represent less than half of that figure. If it is assumed that 40% of this figure represents solvent use, the total is 60 x 10 Ib/yr (27 x 10 kg/yr). Because it is expected that the largest single solvent application is in rubber tires and miscellaneous rubber products, it is further assumed that 80% of the total estimated solvent use is found in 67 ------- f z o HI O O O UJ Z UJ N Z 800 700 600 500 400 300 200 100 90 80 70 60 50 40 30 20 10 I I I •§> • a — D ANT1-OXIDANT PLANT (3-5 hr)" • SPECIALTY POLYMER PLANT (7 he) • CB-EPDM PLANT (5-7 hr)f O TWO SAMPLES WITH THE SAME COORDINATES - I -- I I II 0.1 .2 .3 .4 DISTANCE - km .5 .6 .7 .8 .9 1.0 * The hours shown in parenthesis are approximate averaging times for the samples taken at each plant t Points plotted by B. F. Goodrich Personnel (Kllrov, personal communication, 1978) FIGURE VI-1. SAMPLING DATA FOR THREE SOLVENT OPERATIONS 68 ------- Table VI-2 AVERAGE NUMBER OF EMPLOYEES PER PLANT FOR SELECTED SOLVENT OPERATIONS Average Number of SIC Number Item Employees/Plant 221 229 278 282 285 301 302 303 304 306 307 31 379 Floor covering mills Miscellaneous textile goods Blankbooks and bookbinding Plastics materials, synthetics Paints and allied products Tires and innertubes Rubber and plastics footwear Reclaimed rubber Rubber, plastic hose, and belting . Fabricated rubber products Miscellaneous plastic products Leather and leather products Miscellaneous transportation equipment 113 60 35 351 41 522 295 45 354 89 45 84 38 Source: adapted from 1972 Census of Manufacturers. 69 ------- Table VI-3 NUMBER OF PLANTS AND EMPLOYEES FOR SOLVENT OPERATION WITH HIGH POTENTIAL FOR BENZENE EMISSIONS Tires and Innertubes t E Alabama Arkansas California Colorado Connecticut Delaware Florida Georgia Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Nebraska New Hampshire New Jersey New York North Carolina North Dakota Ohio Oklahoma Pennsylvania Rhode Island South Carolina Tennessee Texas Utah Virginia West Virginia Wisconsin Total 10 5 22 2 1 9 10 5 5 2 3 27 7 14 12 11 2 180 800 400 500* 900 1800 200 500* 360 700 1750 600 1750 600 600 600 100 400 1000 600 500* 460 500* 360 1750 Rubber, Plastic Hose and Belting 1 300 8 750 1 350 2 100 2 900 4 2 2 3 18 5 15 1 4 1 1 83 400 100 200 750 450 100 600 600 350* 360 900 600 300 200 300 750 150 Rubber and Plastic Foocware 0 E 1 300 3 100 1 300 3 1200 4 450 3 600 2 375 3 250 5 360 3 1200 12 300 Plastics Materials, Floor Covering Synthetics Mills 7 5 10 4 1 2 _1 97 100 250 150 180 450 50 250 900 200 150 200 150 750 51 9 6 10 11 27 9 3 3 10 14 5 21 13 4 5 3 35 20 22 37 27 15 15 35 10 6 10 502 400 40 200 700 580 100 100 160 100 100 450 264 580 200 300 200 150 50 70 150 100 700 200 400 1100 1400 280 1800 1200 100 7 300 5 150 62 100* 247 100 7 100 2 100 100 10 100 1 1800 2 150 3 100 17 20 38 100 6 27 3 30 20 4 449 200 200 25 100 80 100 600 Number of Plants 26 12 146 4 15 8 14 270 50 22 8 6 17 14 5 10 53 19 6 9 14 3 12 61 52 35 38 35 14 31 10 47 53 50 2 19 8 13 1311 I » Number of plants E - Average number of employees per plant * - The average plant size for the category. This was used when it was not possible to determine an average plant size for the State from Che listed information. Source: 1972 Census of Manufacturers, Bureau of the Census; 1975 Statistical Abstract of the United States. Bureau of Che Census. 70 ------- rubber-related manufacturing. Therefore, the amount allocated to rubber tires and miscellaneous rubber products is estimated to 48 x 10 Ib/yr (22 x 10 kg/yr). Table VI-3 shows 360 plants in rubber-related manufac- turing. Using this total, the average benzene consumption per plant is estimated at 0.13 x 10 Ib/yr (0.06 x 10 kg/yr). Estimating the level of risk associated with each plant is difficult. In most operations, nearly 100% of the quantity used as a solvent is emitted to air or water. Because benzene is highly volatile, it is likely that most of the solvent is emitted to the atmosphere. If all solvent were emitted to the air, an average plant in rubber-related manufacturing would have an emission rate of 2 g/s if uniform solvent use over a 24-hour, 365-day work year is assumed. The resulting benzene concentrations would range from approximately 7 ppb at the plant perimeter to 0.1 ppb at 20 km 2 (if an area-wide emission within a 0.06 km area is assumed: see Table IV-5). Although more exact estimates are impossible, given the available information, the potential for environmental exposures appears to be significant. The states containing the most plants with high potential for atmospheric benzene emissions are identified in Table VI-4. It is im- possible to discern with certainty whether or not benzene is actually used at these facilities. The probability of benzene use is high, however, and, if used, the probability of annual average benzene concentrations of 0.1 ppb or greater is significant. In fact, all the plants identified in Table VI-4 are at least two times larger than the average plant size in their category (based on total number of employees). This same methodology can be used to determine potential emissions in the remaining two categories: plastics materials, synthetics, and floor covering mills. If it can be assumed that they account for 15% of benzene consumed for solvents, the total use for these two manufac- turing processes is estimated to be 9.0 x 10 Ib/yr (4 x 10 kg/yr). 3 With 951 plants, the average benzene consumption is 9 x 10 Ib/yr 3 (4 x 10 kg/yr) per plant. The emission rate calculated for an average plant is 0.1 g/s, or more than 1 order of magnitude lower than that for 71 ------- Table VI-4 STATES WITH THE HIGHEST POTENTIAL FOR ATMOSPHERIC BENZENE FROM SOLVENT OPERATIONS Number of State Plants Tires and innertubes Connecticut Kansas Maryland Ohio Wisconsin 1 2 2 27 2 Average Number of Employees Per Plant 1,800 1,750 1,750 1,000 1,750 Average State Density (1974) (People/km2) 244 11 159 101 32 Plant Size as Compared to Estimated Average Plant* 3x 3x 3x 2x 3x Rubber, plastic hose, and belting California Delaware Kentucky North Carolina Tennessee 8 2 1 2 1 750 900 750 900 750 52 111 33 42 38 2x 2.5x 2x 2.5x 2x Rubber and plastics footwear Connecticut Georgia Rhode Island Wisconsin 3 3 2 1 1,200 600 900 750 244 32 343 32 4x 2x 3x 2.5x See text for discussion of the estimated average plant size. Source: 1972 Census of Manufacturing and 1975 Statistical Abstract of the United States (Bureau of Census). 72 ------- rubber-related manufacturing. Thus-, if the estimated percentage of benzene use attributed to the rubber industry versus other solvent uses is correct, the exposures related to other solvent operations are minimal. As noted earlier, use of benzene as a solvent in operations other than the rubber industry is generally declining. Although it is also declining in the rubber industry, the use volume is still presumed to be high (ADL, 1977a). In summary, although little is known about the use of benzene as a solvent, present indications are that its use for this purpose is declin- ing. Crude estimates of emissions and available monitoring data indicate that there is a potential for environmental exposures as long as benzene is used as a solvent. Available monitoring data indicate that the levels could be high in the vicinity of some facilities. Rubber-related manu- facturing is estimated to be the largest source of population exposures in this category, although estimating the population exposed was impossible from the information available. Consequently, further study of solvent operations including volumes of benzene, ventilation practices, and characterization of emissions is warranted. It is likely that environ- mental exposures will increase because OSHA regulations will require reduced occupational exposures. 73 ------- VII STORAGE AND DISTRIBUTION OF GASOLINE A. Sources Storage and distribution of gasoline represent potential sources of atmospheric benzene in the environment. There are two main emission pathways: (1) evaporation and spills during loading and unloading and (2) spills from collisions in transportation. Gasoline transfers normally occur at petroleum refineries and at numerous storage sites throughout the United States. Gasoline is usually stored in closed containers located in remote locations. Although evaporation loss from storage tanks has been observed, most of the benzene released into the environment is believed to result from the operations of loading and unloading the gasoline. Spills from collisions involving gasoline transfer vehicles account for negligible benzene losses. The gasoline marketing distribution system is shown in Figure VII-1. 1. Storage Storage facilities consist of closed storage vessels, including pressure, fixed-roof, floating-roof, and conservation tanks. Ordinary fixed-roof tanks store less volatile petroleum products, whereas floating- roof tanks are most commonly used to store gasoline. Diagrams of several of these tanks are shown in Appendix A. Emissions of benzene from storage in a floating-roof tank occur primarily from standing and withdrawal (wetting) losses. Fixed-roof tanks have "breathing" losses caused by expansion and contraction of the vapors due to diurnal changes in atmos- pheric temperature. Because of the low volume of gasoline stored in fixed-roof tanks, breathing losses are not considered to be a significant source of atmospheric benzene. Limited data have been reported on benzene exposures adjacent to storage facilities. A survey of industry reported an average of 375 ppm of benzene measured next to the sampling port on top of a benzene storage tank (Young, 1976, cited in PEDCo, 1977). 75 ------- REFINERY STORAGE SHIP, RAIL. BARGE vSERVICE STATIONS BULK TERMINALS TANK TRUCKS AUTOMOBILES, TRUCKS PIPELINE BULK PLANTS TRUCKS COMMERCIAL, RURAL USERS SOURCE: PCDCo, 1977 FIGURE VII-1. THE GASOLINE MARKETING DISTRIBUTION SYSTEM IN THE UNITED STATES 76 ------- Standing emissions are caused by improper fit of the seal and shoe to the vessel shell. Small losses also occur when vapor escapes between the flexible membrane seal and the roof. Withdrawal or wetting losses are caused by evaporation from the tank walls as the roof descends during emptying operations (PEDCo, 1977). 2. Distribution The gasoline distribution system involving transport from the petroleum refineries to the consumer may also be a significant source of atmospheric benzene (see Figure VII-1). Bulk terminals represent intermediate stations set up to serve near-source regional markets. Gasoline at bulk terminals is transferred directly from refinery by ships, rail tank cars, barges, and pipelines. Bulk plants, on the other hand, are designed for local markets and their supplies are distributed by tank trucks. Service stations that fuel public motor vehicles are supplied by tank trucks from either bulk terminals or bulk plants. Privately owned commercial operations, such as those providing fuel for vehicles of a company fleet, are generally supplied by tank trucks from an inter- mediate bulk installation. Most of the emissions take place during transfers of the gaso- line to tank trucks. These losses occur at a rate directly proportional to the amount of gasoline passing through the particular location. Because many tank trucks are filled at one bulk terminal or plant, benzene emissions from that procedure are potentially much greater. As empty tank trucks are filled, hydrocarbons in the vapor space are dis- placed to the atmosphere unless vapor collection facilities have been provided. The quantity of hydrocarbons contained in the displaced vapors depends on the vapor pressure, temperature, method of tank filling, and conditions under which the truck was previously loaded. A schematic drawing of liquid and vapor flow through a typical bulk terminal is found in Appendix A. All monitoring data collected to date have concerned possible occupational exposures. Measurements at several bulk loading operations in Britain showed ambient benzene concentrations ranging from 0.1 to 77 ------- 7.7 ppm (NIOSH, 1974). In the same study, NIOSH also evaluated worker exposure during loading and weighing of rail tankers with gasoline from storage tanks. An exposure equivalent to 14 ppm over an 8-hr workday was estimated. Thus, environmental exposure to benzene from gasoline distribution systems appears to require some evaluation. Gasoline is loaded from storage tanks to transport trucks (tank cars) by two basic methods: top loading and bottom loading (PEDCO, 1977). Top loading can be done by splash fill or submerged fill. The former method involves free fall of gasoline droplets and thus promotes evaporation and possibly liquid entrainment of these droplets in the expelled vapors. In subsurface or submerged filling, the gasoline is introduced below the liquid surface in the tank. Bottom loading of gasoline is comparable to submerged top loading. B. Methodology and Exposures The emission factors for benzene losses from gasoline storage and transfer are shown in Table VII-1. Because bulk gasoline plants are low-volume operations (4,000 gal/day) and are often located in rural areas, they are not considered in this analysis. Bulk terminals, however, are high-volume operations (250,000 gal/day) and are generally located near urban demand centers—commonly in highly industrialized areas or on city peripheries where population densities are low. A bulk terminal has at least three storage tanks, one for each 3 3 grade of gasoline; each tank holds 55,000 bbl each (8.7 x 10 m ). Rough ambient benzene concentration estimates for the vicinity of bulk terminals were based on emission factors, assumed storage and loading volumes, and the dispersion modeling results discussed in Chapter IV. A typical bulk terminal has the following characteristics: average tank size, 3 3 8.7 x 10 m ; 28-day retention time; three gasoline storage tanks of average size; gasoline loading equaling 250,000 gal/terminal/day; and 2 facility size of 0.01 km . The emission rates for each type of control are calculated as follows: 78 ------- Table VII-1 EMISSION FACTORS FOR BENZENE LOSSES FROM GASOLINE STORAGE AND DISTRIBUTION Source Loading Uncontrolled Controlled Storage Uncontrolled Controlled Emission Factor (g/gal) Reference 1.14 x 10 1.14 x 10 -2 -3 4.0 x 10 4.0 x 10 -2 -3 1 2 1 3 Key to references: 1. Durham, personal communication, 1978. 2. Polglase, personal communication, 1978. 3. Burr, personal communication, 1978. Uncontrolled Case Loading Emission rate = (emission factor) (volume loaded) (day/s) = (1.14 x 10~2 g/gal) (2.5 x 105 gal/day) (day/86,400 s) _2 = 3.3 x 10 g/s . 79 ------- Storage Emission rate = (emission factor)(number of tanks)(tank volume)(days/s) = (4.0 x 10~2 g/gal)(3)(2.3 x 106 gal/28 days)(day/86,400 s) = 1.14 x 10"1 g/s Total emission rate = 1.47 x 10 g/s Partially Controlled Case—Controlled Storage, Uncontrolled Loading _2 Loading emission rate = 3.3 x 10 g/s _2 Storage emission rate = 1.14 x 10 g/s _2 Total emission rate = 4.44 x 10 g/s Controlled Case _3 Loading emission rate = 3.3 x 10 g/s _2 Storage emission rate = 1.14 x 10 g/s _2 Total emission rate = 1.47 x 10 g/s The ambient benzene concentrations can be estimated from the dis- persion modeling calculations of Youngblood (1977c, 1978) that assume uniform emissions throughout the terminal area. By applying the estimated emission rate to the results presented in Table IV-4 (Chapter IV) for 2 the indicated terminal area of 0.01 km , the dispersion curves shown in Figure VII-2 are generated. Note that all annual average concen- trations are below the detectable limit. For comparison, the 8-hour worst case is also shown for each type of control. To determine whether larger operations would cause exposures above the detectable limit, a 10-tank bulk terminal was also evaluated. The characteristics of the facility remain the same, except for gasoline loading of 8.3 x 10 gal/day and faci.' The calculated emission rates follow: 5 7 loading of 8.3 x 10 gal/day and facility size estimated a 0.06 km . 80 ------- 4.0 1.0 I g < cc z LU O o u m Z LU N 0.1 0.01 1 I I I 1 1 UNCONTROLLED 8-HOUR WORST CASE PARTIALLY CONTROLLED 8-HOUR CONTROLLED 8-HOUR UNCONTROLLE ANNUAL AVERAGE PARTIALLY CONTROLLED — ANNUAL AVERAGE 0.1 Source: SRI ESTIMATES 1.0 DISTANCE-km 10 20 FIGURE VII-2. ESTIMATED DISPERSION CURVE FOR A 3-TANK GASOLINE BULK TERMINAL 81 ------- Uncontrolled Case Loading: 1.1 x 10 g/s Storage: 3.8 x 10 g/s Total emission rate = 4.9 x 10 g/s Partially Controlled Case—Uncontrolled Loading, Controlled Storage Loading: 1.1 x 10 g/s _2 Storage: 3.8 x 10 g/s Total emission rate = 1.5 x 10 g/s Controlled Case _2 Loading: 1.1 x 10 g/s _2 Storage: 3.8 x 10 g/s Total emission rate = 4.9 x 10 g/s The emission rates are again applied to the dispersion modeling 2 results of Youngblood (1977c, 1978) for the 0.06 km dispersion curve (Table IV-4). The dispersion curves shown in Figure VII-3 are then estimated. Annual average concentrations fall below the detectable limit for all cases within 500 m of the bulk terminal facility. Because the facility boundary is estimated to be approximately 200 m on each side, the number of people exposed to annual average concentrations higher than 0.1 ppb is assumed to be minimal. The results of this analysis indicate that few members of the public are exposed to annual average benzene concentrations higher than 0.1 ppb. As shown, some people are exposed to 8-hour worst case concentrations between 0.1 and 1.0 ppb. Nevertheless, exposures to the public are considered minimal, although occupational exposures may be high. No information is available about the number of gasoline storage terminals in an average terminal facility. Therefore, the analysis here 82 ------- 4.0 1.0 a z cc z 111 o z o o LU z Ul N Z 111 00 0.1 0.01 I I I UNCONTROLLED 8-HOUR WORST CASE PARTIALLY CONTROLLED 8-HOUR CONTROLLED 8-HOUR UNCONTROLLED ANNUAL AVERAGE PARTIALLY CONTROLLED ANNUAL AVERAGE CONTROLLED ANNUAL AVERAGE DETECTABLE LIMIT _J 0.1 Source: SRI ESTIMATES 1.0 DISTANCE-km 10 20 FIGURE VI1-3. ESTIMATED DISPERSION CURVE FOR A 10-TANK GASOLINE BULK TERMINAL 83 ------- merely shows a range of possible facilities. Although it is not known how many terminals have floating roofs (90-95% more control then fixed roof tanks), estimates are that 70 to 80% of a total of 2700 terminals are controlled in this manner (Burr, personal communication, 1978). ------- VIII URBAN EXPOSURES A. Sources Urban exposures to benzene come from many sources, including chemical manufacturing plants, automobile exhaust, gasoline service stations, gasoline evaporation, and losses through transportation and storage of benzene and gasoline. Because benzene is not routinely monitored in ambient air, few sampling data exist. A study by Altshuller (1969, cited in Mitre, 1976) estimated normal benzene concentrations at between 10 and 50 ppb. This estimate appears to be quite high when compared with other benzene sources discussed previously. In 1973, the General Motors Atmospheric Research Laboratory monitored ambient air quality in Denver for a variety of hydrocarbons. Average benzene concentrations of 3 ppb were found, with a maximum of 30 ppb (Ferman et al., 1977). A study of atmospheric benzene and toluene levels in Toronto found a maximum concen- tration of 98 ppb, with an average concentration of 13 ppb (Pilar and Graydon, 1973). That study concluded that benzene contamination of the air was related to automobile emissions based on three factors: (1) the ratio of benzene to toluene, (2) the presence of distinct peak periods for both hydrocarbons at rush hour periods, and (3) the relative concen- trations detected at various sampling stations. Research Triangle Institute (1977) collected grab samples in urban areas with high industrial activity (see Table VIII-1). Measured benzene concentrations varied significantly—from a trace to 94 ppb. Some of the reasons for such variation include meteorological conditions, density of automobiles in urban areas, industrial emissions, and sampling periods. Gasoline contains varying amounts of benzene, depending on lead content and refinery source, among other things. Before 1974, the average benzene content in U.S. gasoline was less than 1% by liquid volume (Runion, 1975). More recent data (Runion, 1976) indicate that the average benzene content has been increased to maintain octane levels as lead 85 ------- Table VIII-1 RESULTS OF AMBIENT BENZENE MONITORING IN URBAN AREAS WITH HIGH INDUSTRIAL ACTIVITY oo ON Location Patterson, NJ Clifton, NJ Passaic, NJ Hoboken , NJ Newark , NJ Staten Island, NY Edison, NJ Houston, TX Los Angeles, CA Long Beach, CA St. Louis, MO & vicinity Baton Rouge, LA & vicinity Industrial Activity A, I A, I A, I A,I A,I A, I A, I 6C, 5P, ICo, A A, I A, I 1C, ICo, IP, A 1C, IP, A Average Sampling Time (min) 42 39 39 39 38 37 42 72 52 52 420 i 610 Number of Samples 1 1 1 1 1 1 1 3 2 1 6 21 Average Benzene Concentration (ppb) 0.7 trace 2.0 trace 94 0.7 1.0 2.6 5.5 7.1 18.9 1.0 Where known, benzene production or consumption facilities are listed. Key: A = large automobile emission; I = general industrial activity; C = chemical manufacturers using benzene; Co = coke oven; P = petroleum refinery. Source: Research Triangle Institute, 1977. ------- content has been reduced. Current estimates of average benzene content in gasoline range from 1.24 to 2.5% by liquid volume (PEDCo, 1977). Tables VIII-2 and VTII-3 show the results of analyses of gasoline from different refinery sources; these results indicate substantial variation among refineries and types of blends. Table VIII-2 TYPICAL LIQUID VOLUME-PERCENT OF BENZENE IN GULF U.S. GASOLINES, OCTOBER 1976 Vol% Benzene Refinery Source A B C D E F Average Standard deviation Good Gulf \ 0.54 1.99 1.19 . 1.59 1.25 0.85 1.24 0.52 Gulf Crest 0.88 1.45 1.21 1.18 1.98 0.82 1.25 0.43 No-Nox 1.16 0.85 0.81 1.49 2.39 0.88 1.26 0.61 Source: Runion, 1976 (cited in PEDCo, 1977). Gasoline is a mixture of a wide variety of hydrocarbons and fuel additives. Emissions from gasoline evaporation or exhaust contain many chemical compounds, some of which have demonstrated toxic and/or carcino- genic properties. For example, concern has already been raised about three fuel additives: tetraethyl lead, ethylene dibromide, and ethylene dichloride. Appendix E lists more than 100 hydrocarbons and an equal number of fuel additives commonly found in gasoline. Few data have been generated to quantify possible exposures to these chemical compounds. Such estimates are difficult because of the significant variation among refinery blends. 87 ------- Table VIII-3 BENZENE CONCENTRATION IN DIFFERENT GRADES AND SEASONAL BLENDS OF GASOLINE Company — Typical Service Station Tresler-Comet Bonded Bonded Clark Gasoline Grade Premium Regular Unleaded Regular Unleaded Regular Unleaded Regular Unleaded Vol% Benzene in Bulk Sample Summer 1.11 1.21 1.41 0.88 1.19 0.88 1.20 0.97 1.09 Winter 1.10 1.00 1.60 0.88 ' 1.60 0.88 1.60 2.00 1.10 Average Vol% Benzene 1.11 1.11 1.51 0.88 1.40 0.88 1.40 1.49 1.10 Source: National Institute of Occupational Safety and Health, 1976 (cited in PEDCo, 1977). To determine average urban exposures throughout the United States, it is necessary to restrict the analysis. Although substantial variation probably occurs from one urban area to another, it is nonetheless possible to determine a reasonably accurate estimate of annual average exposures related to two definitive sources: evaporative losses at service stations and automative emissions from tailpipe emissions and evaporative losses. B. Methodology and Exposures 1. Urban Exposures from Automobile Emissions The benzene content in gasoline varies widely, with an average of approximately 1.24% by liquid volume. In addition, catalytic converters on automobiles can reduce benzene in vehicle exhaust by 30 to 80% (Johnson, 1977). Thus, similar variation in benzene emitted to the atmosphere can be expected from evaporation of gasoline and from vehicle exhaust emissions. 88 ------- EPA has conducted dispersion modeling of automobile emissions. In the Hanna-Gifford dispersion model used by Schewe of EPA (1977), concentration depends on areawide emissions and wind speed. An empirical factor is also applied. By applying generalized emission factors, area- wide emissions were estimated from vehicle miles traveled (the total number of miles traveled in a given area in a year by all automobiles) and from the number of registered automobiles. Table VIII-4 presents the results of this study. In central cities, the concentrations range from 1.0 ppb to 4.0 ppb, whereas in suburban areas the concentrations are generally below 1.0 ppb. Limited data are available concerning urban exposures from automobile emissions. Consequently, it is difficult to develop accurate techniques to predict benzene levels in urban areas. Uncertainties include: benzene content in gasoline; control technology; deterioration of the control technology over time; and dispersion characteristics of benzene under variable meteorological conditions. Thus, a simplified model is employed to provide general estimates of ambient concentrations. The Hanna-Gifford dispersion model (Gifford and Hanna, 1973) as applied by Schewe (1977) is used for this analysis. Inputs to the model include: number of vehicle registrations, total number of vehicle miles traveled (VMT), area size, and average annual wind speed. The tailpipe emissions are estimated by the following equation (Schewe, 1977): . . 2. 0.22 g VMT 1 ,0 .. Qtail(g/S"m ) ' mile ~s~ Area of study (m2) (8>1) The emission factor of 0.22 g benzene per mile is a composite emission factor for 1976 (Schewe, 1977). The evaporative emissions are calculated as follows: Q , , _ 2 0.148 g 3.3 trips // veh. 365 days year 1_ evap 8 ra ' ~ trip veh. -day 1 year 3.154 x 10? s area (8.2) 89 ------- Table VIII-4 ESTIMATES OF ANNUAL AVERAGE BENZENE CONCENTRATIONS IN FOUR URBAN AREAS vO o City Dallas City Suburbs Los Angeles City Suburbs St. Louis City Suburbs Chicago City Suburbs 10 Vehicle Miles Traveled 6.14 5.36 10.2 21.5 2.86 7.71 18.8 23.5 Registered Automobiles 619,684 540,786 2,044,203 4,299,073 378,280 1,020,219 1,860,292 2,327,206 Land Area (108 m2) 6.9 43.0 12.0 54.0 1.6 61.0 5.8 88.0 ^evap g/s m ) 5.08 .719 9.63 4.53 13.5 .944 18.2 1.49 Qtail (10-92 g/s m 62.2 8.80 59.3 28.0 126.0 8.80 227.0 18.6 QT (10-92 g/s m ) 67.3 9.52 68.9 32.5 140.0 9.74 245.0 20.1 _ Average Annual Wind Benzene Speed (m/s) (yg/m3) 5 3.03 0.43 2 7.75 3.66 4 7.88 0.55 4 13.78 1.13 Concentration (ppb) .95 .13 2.4 1.1 2.5 .17 4.3 .35 1976 projections 0 = Evaporative emissions from automobiles. evap Q = Tailpipe emissions from automobiles. t ai-L Q = Total automobile emissions Source: Schewe, 1977 ------- By multiplying the constants in this equation, we get the following: O ( I - ^"\ = 5.653 x 10 g number of vehicles ^evap S S m veh. s area of study (ra^) (8.3) This technique assumes that each vehicle emits 0.148 g of benzene per trip and that the average vehicle travels 3.3 trips per day (Schewe, 1977) The total emissipns for automobiles can be expressed as follows: \ = 'tail + Qevap (8'4) Equation (8.4) is essentially the summation of Equations (8.1) and (8.3). To calculate the average annual areawide benzene concentrations, Equation (8.5) is used: 225 Q *= (8'5) The average annual wind speed, u, in the area of study was obtained from Figure VIII-1. Because wind speed (and thus dispersion) increases in the afternoon, the morning values were used to estimate higher concen- trations. The number 225 is an empirical factor derived from several studies that gave very good results for long-term averages; it applies to light-duty vehicles such as passenger cars. Because of the general unavailability of 1976 data for all urban areas, 1973 data were used as much as possible in this estimation. Comparisons of 1973 with 1976 data indicated that the changes was less than 3% and had a negligible effect on the final results. The following data sources were used: • 1973 Standard Metropolitan Statistical Area (SMSA) and county populations — U.S. Bureau of the Census, 1976, Series P-25, No. 618. 1973 SMSA and county automobile registrations — U.S. Department of Transportation, Federal Highway Administration, 1974, Table MV-21. 91 ------- Average annual vehicle miles traveled by size of SMSA— Federal Highway Administration, 1972, Nationwide Personal Transportation Study, Report No. 2, Table 9. Average annual wind speed—EPA, 1972, Publication No. AP-101. SMSA, county and city land areas—Bureau of the Census, 1972 County and City Data Book. Source: EPA, 1971 FIGURE VIII-1. ISOPLETHS (m/sec) OF MEAN ANNUAL WIND SPEED THROUGH THE MORNING MIXING LAYER A detailed analysis was conducted for the six largest cities in the U.S. (populations of more than 1 million). Table VIII-5 presents the results. Because input data were slightly different, the results differ somewhat from those shown in Table VIII-4. For example, the suburban area used in this estimate may include a larger area than that used in the Schewe estimates. Suburban areas are defined as those areas outside the central city but within the SMSA. Because no VMT and registration data were available at the city level, they were extrapolated either from SMSA data or county data and were based on the fraction of the population residing 92 ------- Table VI11-6 ESTIMATES OF AVERAGE ANNUAL BENZENE CONCENTRATIONS FOR CITIES WITH POPULATION EXCEEDING 1.000.000 VO City Chicago Detroit Houston Los Angeles New York Philadelphia Population 103 6,999.8 4,446.3 2,163.4 6,938.3 9.746.4 4,826.3 Population 103 3,173 1.387 1,320 2,747 7,647 1,862 Area ID'*' 0.57 0.35 1.1 1.2 0.77 0.33 Automobile Registration 1,324.171 675,065 701,766 1,490,483 1,707,891 944.660 vehicle 103 11.5 11.5 14.0 11.5 11.5 11.5 WIT 1.5 0.77 0.98 1.7 1.9 1.0 u Ws) 5 6 6 3 7 6 10-' 1.8 1.5 0.63 0.98 1.7 2.0 evap ID"8 g/s-rn^ 1.3 1.0 0.36 0.67 1.2 , 1.5 i 1.9 1.6 0.66 1.0 1.8 2.1 Centr; 8.6 6.0 2.5 7.5 5.9 8.0 il City ppb 2.7 1.8 0.7 2.3 1.8 2.5 Suburban 1.1 1.2 0.23 0.4 0.3 1.5 Composite ppb 1.9 1.5 0.5 1.3 1.0 2.0 Source: SRI estimates based on Hanna-Gifford model as applied by Schewe (1977); data source* listed In text. ------- in each area. The results show that the estimated benzene concentrations in city and suburban areas range from 0.7 to 2.7 ppb and 0.2 and 1.5 ppb, respectively. The composite benzene concentrations in the six correspond- ing SMSAs ranged from 0.5 to 2.0 ppb. It is expected that people living in urban areas are exposed to higher levels of benzene from automotive emissions than those living in rural areas. Consequently, our approach was designed to include as many urban residents as possible. Although 43% of the total urban population resides in central cities (as defined by the Bureau of the Census), 83% of the total urban population resides in SMSAs. Thus, a greater percentage of the urban population is captured by using SMSAs as study areas. The six largest cities are in SMSAs with more than 2 million population. To analyze the remaining SMSAs, the following population size categories were employed (U.S. Bureau of the Census, 1976, Series P-25, No. 618): SMSA Population Size Category Number of Areas 2,000,000 or more 15 1,000,000 - 2,000,000 20 500,000 - 1,000,000 37 250,000 - 500,000 63 less than 250,000 124 SMSA composite benzene concentrations were estimated for seven areas that represent four population size categories (see Table VIII-6). For SMSAs with population exceeding 500,000, the composite average annual benzene concentrations ranged between 0.1 and 0.4 ppb. However, SMSAs of less than 500,000 were below 0.1 ppb. It may be assumed from this analysis that the SMSAs with population less than 500,000 have average annual benzene concentrations less than 0.1 ppb. The estimates of urban exposures from automobile emissions are order-of-magnitude estimates that are based on a simple dispersion model. Note that, in certain locations and under certain meteorological conditions, benzene concentrations may be a factor of 10 higher than those listed. 94 ------- VO Table VIII-6 ESTIMATES OF AVERAGE ANNUAL BENZENE CONCENTRATIONS FOR SELECTED SMSAs SMSA Population 2 Area (m ) Automobile Registration VMT/ ^tail ^evap T Benzene Vehicle VMT u 10~9 10~10 10~9 Concentration 103 109 m/s g/s-m2 g/s-m2 g/s-m2 pg/m^ SMSAs > 2,000,000 Pittsburgh San Francisco SMSAs 1,000,000 Columbus Milwaukee SMSAs 500,000 - Sacramento Providence- Warwi ck- Pawtucket SMSAs 250,000 - Wichita Harrisburg 2,333,600 3,135,900 - 2,000,000 1,055,900 1,423,200 1,000,000 851,300 854,400 500,000 375,600 425,500 7.8 x 109 6.2 x 109 6.2 x 109 3.7 x 109 8.7 x 109 q 2.4 x 10 6.2 x 109 4.1 x 109 2,358,600 688,300 567,803 642,531 439,803 869,100 221,715 198,997 11.3 26.0 5 23.0 17.0 25.0 1.1 11.5 7.7 3 8.5 6.2 9.1 .68 11.3 6.4 5 7.2 5.1 7.8 .35 11.3 7.2 5 13.0 9.8 14.0 .62 11.3 4.9 3 3.9 2.8 4.2 0.3 11.3 9.8 7 28.0 20.0 30.0 0.9 10.3 2.3 7 2.5 2.0 2.7 .08 10.3 2.0 5 3.4 2.7 3.7 .16 ppb .4 .2 .1 .2 0.1 0.3 <0.1 < 0.1 Source: SRI estimates using Hanna-Gifford dispersion model as applied by Schewe (1977). ------- In addition, central city areas ( as shown in Table VIII-5) may have consistently higher levels than surrounding areas because of traffic density, frequency of intersections, and street density. Because the model only includes automobile emissions, areas with substantial commercial or bus transportation may have higher levels than estimated. Also, the model is extremely sensitive to area size as Table VIII-5 indicates. Thus, composite SMSA benzene concentrations provide the most reasonable estimate of the average annual exposures for an urbanized area. The total estimated urban population exposed to benzene in concentrations greater than 0.1 ppb from automobile emissions is shown in Table VIII-7. The 1974 SMSA populations for Chicago, Detroit, Los Angeles, New York, and Philadelphia were summed to estimate the population exposed to average annual benzene concentrations of 1.1 to 4.0 ppb. The 1974 SMSA population of Houston plus the remainder residing in SMSAs with populations greater than 500,000 were summed to estimate the total population exposed to average annual benzene concentrations between 0.1 and 0.1 ppb. The results indicate that 114 million people, or 73% of the total SMSA population, are exposed to average annual benzene concentrations greater than 0.1 ppb. Table VIII-7 URBAN POPULATION EXPOSURES RELATED TO AUTOMOBILE EMISSIONS Annual Average Benzene Concentration Source 0.1-1.0 1.1-4.0 Total Automobile emissions 69,000,000 45,000,000 114,000,000 * 3 To convert to yg/m , multiply concentrations by 3.2; to estimate 8-hour worst case, multiply by 4.1. Source: SRI estimates. 96 ------- 2. Urban Exposures from Gasoline Service Stations People residing in the vicinity of service stations are exposed to benzene emissions from evaporative losses resulting from gasoline pumping by attendants and customers, and from gasoline loading into underground tanks by distribution trucks. The amount of benzene emitted depends on a number of critical factors: ambient temperature, vapor recovery controls, pumping volumes, and the benzene content in gasoline are probably the most important. The United States has approximately 184,000 service stations, and it is expected that,many people are exposed to benzene from these sources. Because the density of service stations in urban areas is high, only urban areas are considered in this analysis. For the population exposed to service station emissions, it is necessary to estimate the stations in urban areas. Service station density can be extrapolated from data presented in Table VIII-8. These data, which have no apparent regional pattern, show an average of 0.7 service station per 1000 population. This density figure can be applied generally to urban areas throughout the United States to give a rough * approximation of the total number of service stations. Urbanized areas provide the best population base. The 1970 population residing in urbanized areas was 118,447,000 (Bureau of Census, 1975). Thus, service stations in urbanized areas are estimated at 83,000, or 46% of all stations, Defined by the Bureau of Census as the central city or cities and surrounding closely settled areas. Sparsely settled areas in large incorporated cities are excluded by this definition. Densely populated suburban areas, however, are included (U.S. Department of Commerce, Bureau of the Census, 1972 County and City Data Book). 97 ------- Table VIII-8 SERVICE STATION DENSITY IN FOUR METROPOLITAN AQCRs AQCR Boston Dallas Denver Los Angeles Number of Service Stations (1977) 2,353 3,218 1,277 7,298 AQCR1" Population (1975) 4,039,800 2,970,900 1,389,000 14,072,400 Service Station1" Density (number/ 1000 population) 0.6 1.1 0.9 0.5 Sources: * ADL t U.S. Department of Commerce, Bureau of Economic Analysis, 1973. f SRI estimates. The atmosphere in the vicinity of gasoline service stations has been monitored in three studies. API (draft report, 1977) monitored eight service stations in various geographic locations with continuous samplers over a 24-hour period. Quality control information is not available for these data. Six of the monitored locations were in urban * or suburban areas. The average benzene concentrations ranged from 3 to 10 ppb within 200 m of the service station (see Figure VIII-2) . The two locations in rural or mountain areas showed generally lower average benzene concentrations ranging from 0.4 to 3.7 ppb within 200 m of the service station (see Figure VIII-3) . The wide variability in the data is probably related to the differing meteorologic conditions, pumping volume, benzene concentration in the gasoline, and ambient temperatures. fc The Pacific Northwest location (C-l) was included in this category because of its proximity to an interstate highway and commercial development. 98 ------- 10 VO VO Ul o 8 ui ui CD 0.3 1 1 1 1 1 1 1 | 1.0 A°A A A A « A •• • • • A — O Urban Midwest, A-1 A Urban Midwest, A—2 O Suburban Eastern, B—1 • Suburban Eastern, B—2 A Pacific Northwest, C— 1 • Urban Eastern, C—2* samples with the same coordinates 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 DISTANCE FROM SOURCE-m 100 300 Because this location was next to an interstate highway, these sampling data were included in this category. t Distances from the source were recalculated from the original data for these locations. The distances shown here represent distances from the gasoling pumps. The original data showed distance from the service station. Source: Adapted from American Petroleum Institute, 1977 FIGURE VIII-2. RESULTS OF ATMOSPHERIC MONITORING IN THE VICINITY OF URBAN-SUBURBAN GASOLINE SERVICE STATIONS, SUMMER, 1977 ------- 30 o o 4 flC z 111 o LLJ Z 1U N Ul m 10 0.3 • A > AA • A • A Mountain, D—1 • Rural West, D-2 /\ Two samples with the same coordinates I A • I I I I I I I I 1.0 10 100 DISTANCE FROM SOURCE-m Source: Adapted from American Petroleum Institute, 1977 FIGURE VIII-3. RESULTS OF ATMOSPHERIC MONITORING IN THE VICINITY OF RURAL-MOUNTAIN GASOLINE SERVICE STATIONS, SUMMER, 1977 300 ------- Battelle (1978a) monitored the atmosphere for benzene in the vicinity of gasoline service stations in the summer of 1977. The results for the three locations in Columbus, Ohio, gave average concentrations ranging from-1.0 to less than 1.0 ppb for a 24-hour period. However, the report urges caution in using these data because of unexplained varia- tions from expected results. The only finding that the report could report with assurance was that benzene concentrations did seem to decrease with distance from the service stations. Benzene concentrations ranged from 10 to 22 ppb 150 m downwind in two grab samples obtained in a resi- dential neighborhood during the filling of an underground storage tank. Radian Corporation monitored the atmosphere for benzene in the vicinity of a gasoline distribution facility in Irving, Texas, for Shell Oil Company (Radian, 1978). The report does not indicate whether the facility was a service station or a gasoline bulk plant. Ten 24-hour samples were collected at the first site 800 m from the facility on top of a two-story motel; they showed an average benzene concentration of 2 ppb. At the second site, approximately 180 m from the facility at ground level, the average benzene concentration from 24-hour samples was 3 ppb. These results would seem to indicate that the facility was responsible for adding approximately 1 ppb to the atmosphere. A third sample site approximately 2000 m from the facility and located near a major highway showed a 7 ppb average for two parallel 24-hour samples. (One sample showed 3 ppb; the second backup sample showed 10 ppb; no reasons was offered for the discrepancy between the two samples.) Separating population exposures related to gasoline service stations from general urban exposures is difficult. Service stations, which are usually located along well-traveled roads, may be isolated or located near other stations. Emissions from service stations vary, based on differences in operating times, pumping volumes, and benzene concentration in gasoline. Benzene concentrations measured at atmos- pheric monitoring stations are influenced by all of these factors, in addition to emissions from automobile exhaust, evaporation of gasoline from parked cars, and emissions for other benzene point sources. With 101 ------- conditions varying from station to station, nationwide benzene exposure levels from this source are difficult to approximate. Because gasoline service stations represent a significant source of benzene exposure to many people, we attempted to estimate the exposure levels and the population-at-risk insofar as possible given the data limitations. Three methods, which are discussed below, were investigated. Point Source Dispersion Modeling—EPA conducted dispersion modeling for a worst-case condition (Youngblood, 1977d) by using the single source (CRSTER) model. Meteorological data for Denver, Colorado, were used to represent a reasonable worst-case location. The model was executed to eliminate nighttime inversions, resulting in enhanced dis- persion and, for low-level sources such as service stations, lowered ground-level concentrations. Table VIII-9 presents the results of the dispersion modeling. In applying the available modeling data to urbanized areas, many difficulties are inherent. Note that the operating conditions, pumping volumes, and the chosen location represent worst-case conditions. In particular, the pumping volume used is approximately four times larger than that for a typical service station. Consequently, extrapo- lating these results to average conditions is difficult. The data seem to indicate, however, that individuals residing within 100 m of a service station may be exposed to annual average concentrations of 1.0 ppb or more, wheras those residing beyond 100 m may be exposed to less than 1.0 ppb on an annual average basis. Uniform Distribution Dispersion Modeling—Because initial efforts to treat service stations as point sources gave unsatisfactory results, we decided to assume that service stations were uniformly distributed and to use the Hanna-Gifford dispersion model to estimate annual average concentrations. This model should be applicable because service stations are widely distributed throughout urbanized areas. (We estimate 1.5 service stations per square kilometer, i.e., 2.4 per square mile.) 102 ------- Table VIII-9 ROUGH DISPERSION MODELING RESULTS FOR GASOLINE SERVICE STATIONS % Benzene a Hours of in Gasoline Calculated Distance (m) Station Operation Vapor Emission Rate (g/s) 50 100 150 200 300 ** 8-Hour Worst-Case Concentration (ppb) Al 8 a.m. - 4 p.m. 0.7 0.019 27 13 8 5 3 6 days/week A2 8 a.m. - 4 p.m. 3.0 0.080 117 57 34 23 12 6 days/week ** Annual Average Concentration (ppb) Bl 24 hours/day 0.7 0.0053 1 <1 <1 <1 <1 7 days/week B2 24 hours/day 3.0 0.023 2 1 1 <1 <1 7 days/week * Pumping rate for all stations is 200,000 gal/month uniformly over hours of operation; rate of evaporative loss for all stations is 10 g/gal pumped. 3 To convert to ug/m , multip Source: Youngblood, 1977d. -** 3 To convert to ug/m , multiply concentrations by 3.2. ------- The same approach used in the previous section was applied here: Total emissions related to evaporation from gasoline service stations were estimated for an area. This result was used as the input to the dispersion equation [Equation (8.5)], along with wind speed for the region. The emission factors were determined through consultation with EPA and are summarized in Table VIII-10. We assumed that 50% of the service stations have submerged fill and 50% have splash fill. The estimates of controlled emissions assume no change in breathing and spilling losses from the uncontrolled situation. Table VIII-10 EMISSION FACTORS FOR BENZENE LOSSES AT GASOLINE SERVICE STATIONS Hydrocarbon Emissions Type of Control Uncontrolled Stage I (controls on gasoline storage/filling operations Stages I and II (controls on gasoline storage/ filling and on auto- mobile refueling Gasoline Storage and Fill (g/gal) Automobile Filling (g/gal) Total (g/gal) Estimated Benzene Emissions* (g/gal) 4.8 0.59 0.59 4.4 4.4 0.73 9.2 5.0 1.32 0.07 0.04 0.01 Hydrocarbon emissions are estimated to contain 0.8% benzene, assuming 1.3% benzene by liquid volume in gasoline. Source: Kleeburg, personal communication, 1978. 104 ------- Currently, Stage I controls are required in 13 AQCRs: Boston, New Jersey-New York, New Jersey-Philadelphia, Pittsburgh, Baltimore, Washington, D.C., Houston, San Antonio, Denver, Indianapolis, Los Angeles, and California's Sacramento and San Joaquin Valleys. Stages I and II controls have only been implemented in the San Francisco Bay Region and in approximately 30% of San Diego service stations. The California Air Resources Board plans to implement Stage II controls in four additional AQCRs (Perry, personal communication, 1978). Separate calculations were made for (1) urbanized areas with uncontrolled service stations, (2) Stage I controls, and (3) Stages I and II controls. Because AQCRs cover a larger area than do urbanized areas, it was necessary to determine the population and land area of all the urbanized areas within a particular AQCR. For example, the New Jersey- Philadelphia AQCR contains the urbanized areas of Philadelphia, Trenton, New Jersey, and Wilmington, Delaware (U.S. Bureau of the Census, 1972 County and City Data Book; Bureau of Economic Analysis, 1973). The average U.S. wind speed was determined by weighting regional average wind speeds by population (see Table VIII-11). Total gallons of gasoline in urban areas was estimated at 4.0 x 10 gallons, based on the 1975 9 urban miles traveled by passenger cars (600 x 10 miles) and an average of 13.74 miles per gallon (U.S. Bureau of Census, 1977 Statistical Abstract). The results of this analysis are shown in Table VIII-12. Note that the estimated levels are more than 1 order of magnitude below concentrations measured by atmospheric monitoring. Several reasons may account for this. As previously mentioned, the Hanna-Gifford dispersion model is sensitive to land areas. We also assumed uniform distribution of service stations, when in reality they are often clustered in groups of three or more in one location. In addition, more service stations are located in central city areas than suburban areas. 105 ------- Table VIII-11 DETERMINATION OF WEIGHTED U.S. AVERAGE WIND SPEED Census Bureau ' Region Northeast Mid-Atlantic E. North Central W. North Central South Atlantic E. South Central W. South Central Mountain Pacific 1970 Population (103) 11,883 37,274 40,313 16,518 30,805 12,839 19,388 8,348 26,600 Percent of Total 5.8 18.3 19.8 8.1 15.1 6.3 9.5 4.1 13.0 Average Wind Speed (m/s) 6.5 6.5 5.5 6.0 5.5 5.0 6.0 4.0 3.0 Wind Speed Component 0.4 1.2 1.1 0.5 0.8 0.3 0.6 0.2 0.4 Total 203,806 100.0 5.5 Average Weighted U.S. Wind Speed =5.5 m/s. Source: U.S. Bureau of Census, 1975 Statistical Abstract; Figure VIII-1; and SRI estimates. 106 ------- Table VIII-12 ESTIMATES OF ANNUAL AVERAGE BENZENE CONCENTRATIONS IN URBAN AREAS FROM GASOLINE SERVICE STATIONS BASED ON THE HANNA-GIFFORD DISPERSION MODEL Estimated Exposed Estimated Benzene Benzene Annual Average Urban % of Total Gallons Emission Emission Benzene Type of Population Urban Pumped/Year Land Area Factor Rate Concentrations Control (106) Population (1010) (103 km2) (g/gal) (g/s) Uncontrolled 68.4 58 2.55 39.3 0.07 60 Stage I 45.4 38 1.7 15.5 0.04 20 (ppb)' Stages I and II 4.5 0.18 1.7 0.01 0.6 0.06 0.05 0.03t * 3 To estimate p,g/m , multiply by 3.2. Because both locations with Stages I and II controls are on the West Coast, the average wind speed of 3 m/s was used for this calculation. If the U.S. weighted average of 5.5 m/s was used instead, the estimated concentration would be 0.01 ppb. Source: SRI estimates ------- Application of the Monitoring Data—Atmospheric monitoring in the vicinity of gasoline service stations seems to indicate that their contribution to the urban atmosphere ranges from 1 to 2 ppb within 100 m of the station. Because of the extent and geographic coverage of the API monitoring data, those data were analyzed further to determine whether they could be applied to other urban areas. Regression analysis was used to fit a curve to the two sets of data shown in Figures VIII-2 and VIII-3. As Figure VIII-4 indicates. fairly good agreement was achieved between the two. Excellent correlation was noted for the curve representing rural-mountain service stations. Benzene concentrations ranged from 2 ppb at the station boundary to 0.5 ppb at 200 m from the station. The urban-suburban curve, on the other hand, showed concentrations ranging from 5 ppb at the station boundary to 3 ppb at 200 m. Correlation of this curve (r = 0.30) with the monitoring data was not as good as the correlation of the rural- mountain curve (r = 0.67), in part because benzene concentrations in urban areas are influenced by many sources other than gasoline service stations. The difference between the two curves ranges from 2.5 to 3 ppb and can be considered to be the background concentration associated with urban areas. This assumption correlates well with other monitoring data and dispersion modeling of urban areas discussed previously in this chapter. The rural-mountain curve should represent the contribution of benzene to the urban atmosphere in the absence of other influencing benzene sources. This curve was used in estimating the population exposed to benzene from gasoline service stations. For purposes of extrapolation, the population residing between 30 and 80 m from a service station is assumed to be exposed to annual average benzene concentrations between 1 and 4 ppb. Those residing from 80 to 300 m from a service station are assumed to be exposed to between 0.1 and 1.0 ppb. Given the available data, precise identification of the point at which the benzene levels drop below 0.1 ppb (the detectable limit) is impossible. Therefore, we assume that a service station's influence on benzene concentrations is minimal beyond 300 m. 108 ------- § 4 01 u 8 UJ Z Ul N Ul CO I I I I | I T CURVES EXTRAPOLATED BY REGRESSION ANALYSIS AS FOLLOWS: URBAN-SUBURBAN C = aDb a = 12.81 b =• -0.26 r =• 0.30 Significant at 90% confidence level RURAL a - 28.34 b--0.77 r = 0.67 Significant at >99% confidence level URBAN- SUBURBAN RURAL- MOUNTAIN I 10 20 30 40 60 80 100 DISTANCE-m 200 300 400 ASSUMED Source: SRI estimates FIGURE VIII-4. REGRESSION CURVES DEVELOPED FROM API ATMOSPHERIC MONITORING DATA COLLECTED IN THE VICINITY OF GASOLINE SERVICE STATIONS 109 ------- The exposed population can be estimated as follows: 1 to 4 ppb o (irr ) (number of service stations) (density of urbanized areas) = popuXcLC ion 9 9 fi u(0.08 km - 0.03 km) (83,000) (1318 people/km ) = 0.9 x 10 0.1 to 1.0 ppb Tr(0.3 km - 0.08 km) 2 (83, 000) (1318 people/km2) = 20 x 1Q6 These estimates, which are only rough approximations, are based on assumptions of uniform distribution of service stations in urbanized areas, uniform pumping volumes, and average population density, and on a curve developed by regression analysis of monitoring data. In reality, more service stations are located in commercial areas than in residential areas, pumping volumes vary substantially, and several service stations are often located in the same general area. One service station was monitored at all sites, except one, for which two stations were monitored (based on site maps accompanying the draft API report) . However, note that monitoring data are not often a good representation of annual average concentrations because of shor-t-term variations in meteorology, operating conditions, sales volume, and other possible benzene sources in the area. Nevertheless, the correlation appears adequate for our rough approximations. Further study is warranted to determine a more accurate estimate of exposure levels, based on pumping volumes, co-location of service stations, their distribution within an urban area, and emission rates. 110 ------- IX SELF-SERVICE GASOLINE A. Sources Service stations are characterized by their services and business operations: full-service stations, split island stations, self-service stations, and convenience store operations. In full-service stations, attendants offer all services, including gasoline pumping and other mechanical check-ups. If fuel is obtained at any of the last three classes of stations, the customers may fill up their tanks themselves. In split island stations, both self-service and full-service is available. While pumping gasoline, an individual is exposed to high benzene levels * released as vapor from the gasoline tank. Although occupants in the car at both self-service and full-service operations receive some benzene exposures, the highest exposures are received by the individual pumping the gas. Because it is difficult to estimate level and length of exposure for occupants, only those individuals obtaining gasoline from self-service pumps are considered. (It is not within the scope of this report to evaluate occupational exposures.) Benzene content of evaporative gases increases and decreases during evaporation, depending on the system temperature and the relative volatilities of all the components of the fuel (Mitre, 1976). Recent information indicates that gases released during automobile fill-ups have little relationship to the benzene content in the gasoline. Rather, the ambient temperature relative to the temperature of the gasoline has the most significant effect, and most of the exposure results from the benzene vapor trapped within the tank, not from the gasoline being pumped (Johnson, 1977). If the gasoline is cold relative to the tank (as in summer), Vapor recovery systems can reduce exposure levels significantly, if properly working and operated. Such systems are required for service stations in parts of California. Ill ------- most of the benzene vapor will be abosrbed into the gasoline. On the other hand, if the gasoline is warm relative to the tank (as in winter), the benzene vapor will be displaced rather than absorbed and more signi- ficant exposures will result. Self-service dispensing of gasoline is a relatively new marketing method pioneered by independent operators on the West Coast and in the southern United States. Today, it accounts for 30% of gasoline sold. The national market-share of the major gasoline producers has decreased recently as independents and others specializing in high-volume, low- margin sales capture a larger percentage. Of the approximately 184,000 conventional service stations and tie-in gasoline operations in the United States, service stations with some self-service operations account for 39% (ADL, 1977b). Table IX-1 indicates the types of service stations offering self-service gasoline. Table IX-1 SELF-SERVICE OPERATIONS Percent of Outlets Offering Self-Service U.S. Total Total self-service 9 Split island with self-service 26 Convenience stores 4 Total outlets with self-service 39 A recent ADL report (1977b) revealed that there are 71,300 outlets with self-service gasoline. Gasoline sold for the year ending May 30, 9 1977, equals approximately 87.4 x 10 gal in the United States. Of this 9 amount, 27.0 x 10 gal (31%) was dispensed at self-service pumps. The market-share of self-service stations was surveyed for four metropolitan Air Quality Control Regions (AQCR): Boston, Dallas, Denver, and Los Angeles. The market-share held by self-service operations varied from 9% in Boston to 45% in Denver (see Table IX-2). Another study by applied Urbanetics, Inc. (1976) surveyed Baltimore and Madison, Wisconsin. The 112 ------- Table IX-2 .GASOLINE MARKET SHARE OF SELF-SERVICE STATIONS IN FOUR AQCRs, SPRING 1977 Type of Operation Boston AQCR Full-service Self-service (total) Split island Self-service Convenience stores Dallas AQCR Full-service Self-.service (total) Split island Self-service Convenience stores Denver AQCR Full-service Self-service (total) Split island Self-service Convenience stores Los Angeles AQCR Full-service Self-service (total) Split island Self-service Convenience stores Number of Outlets 2,253 100 8£ 92 621 656 310£ 226 120 2,518 4,780 3,632£ 1,022 126 Sales Volume (106 gal/yr) 1,045.1 108.6 292.1 235.7 2,472.6 2,154.8 Market Sharing Percent 91% 9 2,094 1,124 480a 444 200 924. 593. 6 8 61 39 55 45 53 47 Split island operations offering full service and self-serve islands. Of these 445 are split island operations that offer full service and mini-serve (attendant-operated) islands. Source: ADL (1977b). 113 ------- results of this study are shown in Table IX-3. It appears that about 40% of the market in urban areas is accounted for by self-service operations. Table IX-3 GASOLINE MARKET SHARE OF SELF-SERVICE STATIONS IN TWO METROPOLITAN AREAS, 1976 Type of Operation Baltimore SMSA Full-service Self-service (total) Split island Self-service Madison SMSA Full service Self-service (total) Split island Self-service Sales Volume (106 gal/yr) 111.5 90.5 25.5 65.0 56.Oc 77.0 17.0 60.0 Market Sharing Percent 55% 45 42 58 Includes the sales from mini-serve (attendant- operated) stations and 50% of the sales from split islands. Source: Applied Urbanetics, Inc. (1976). B. Methodology and Exposures To estimate the people exposed to benzene from this source, several assumptions were necessary. The gasoline pumped through self-service 9 outlets is estimated at 27.0 x 10 gal. The annual average fuel con- sumption per vehicle is 736 gal (U.S. Federal Highway Administration, 1974). If it is assumed that on the average, a person who primarily uses self-service gasoline makes one trip there per week, an average fill-up amount of 14 gal is determined by dividing 736 gal/vehicle/yr by 52 wk/yr. By dividing the average fill-up into the self-service 114 ------- gallons pumped, we estimate trips per year to self-service operations 9 at 1.9 x 10 . When this number is divided by 52 trips per person per year, the people exposed to benzene from this source is estimated at 37 x 10 . This estimate of the population exposed assumes that the individuals using self-service gasoline never obtain gasoline at full- service stations. Battelle conducted a preliminary study (1977b) to determine the benzene exposure levels from self-service gasoline pumping. Three samples of ambient air were taken in the breathing zone of persons filling their tanks. The results, shown in Table IX-4, indicate a wide range in the benzene concentrations of the emissions. The variations seem to be related to the subject's position in relation to the tank opening and the wind direction. Because all measurements were taken on the same day and at approximately the same time, ambient temperature did not cause the variation. Basically, if the subject was downwind of the tank opening, higher levels were recorded. The time-weighted average concentration of benzene from the three samples is 245 ppb. The average length of time taken to fill up a gasoline tank is 1.7 min. Although 14 gal per fill-up is assumed, the wide range in pumping speeds does not allow a precise estimate of time required per fill-up. Table IX-4 SAMPLING DATA FROM SELF-SERVICE GASOLINE PUMPING Customer 1 2 3 Sampling Rate (mL/min) 31 31 31 Nozzle Time (min) 2.5 1.1 1.6 Gallons Pumped 14 8 9 Sample Volume (L) 78 34 50 Benzene Mg/m 115 324 1740 Level ppb 43 121 647 Source: Battelle (1977b). 115 ------- The estimated exposure levels are based on the information contained in Table IX-4. It is recognized that these data are quite limited and highly variable. In states where vapor recovery systems are used, the estimated exposure level may be much lower. It can be estimated that approximately 37 x 10 persons use self-service stations. While filling their tanks once a week, they are exposed to a benzene level of 245 ppb for 1.7 minutes. Their annual exposure is estimated at 1.5 hr. (Table IX-5 summarizes this information.) Table IX-5 ESTIMATED POPULATION EXPOSED TO BENZENE FROM SELF-SERVICE GASOLINE Exposure Type Self-service pumping Exposure Time Annual Exposure Population Exposed to Benzene Concentrations (ppb)* 245.0 Total 1.7 min 1.5 hr 37,000,000 37,000,000 * 3 To convert to yg/m , multiply concentrations by 3.2; to convert annual average exposures to 8-hour worst case, multiply concen- trations by 25. Source: SRI estimates. 116 ------- X ASSESSMENT OF TOTAL EXPOSURE A. Introduction Because benzene sources are widespread, particularly within the urban environment, the exposures of some individuals may be significantly different from those estimated in Chapters III through IX. The results presented in these previous chapters are based on the assumption that individuals living near a source spend 24 hours of each day in that location. In fact, however, many individuals travel from their place of residence to work or shop in other areas. Thus, they are exposed to varying levels of benzene concentrations throughout the day. In this chapter, a rough analysis is made to estimate total exposure to the urban population: Total exposure is the sum of an individual's exposure to all benzene sources over a designated period (e.g., a week or a year) and in varying locations; this exposure, therefore, represents a more realistic estimate of population exposure then indicated previously. In this approach we developed several scenarios that represent typical living patterns of individuals residing in the vicinity of benzene sources. Percentages of time spent in various activities such as sleeping, shopping, commuting to work, traveling on personal business, and working were estimated by using the findings of sociological studies. Assumptions were then made about residence locales and work locations (for those that work). and about what percentage of the population falls into each of these categories. The benzene exposure settings typical for each activity were determined from dispersion modeling and atmospheric monitoring, data described in Chapters III through IX. The percentage of time spect in 1 year in various activities was multiplied by the associated benzene exposure setting (ambient benzene concentration measured in ppb) and summed to determine an individual's total exposure. Note, however, that because so few data exist, this approach necessarily has limitations and is considered a first-cut analysis. 117 ------- Estimates of total exposure are linked to each source category (e.g., chemical manufacturing facilities, petroleum refineries, or urban areas). Our approach assumes that those living in the vicinity of one point source, such as a coke oven, are unaffected by other benzene sources until they move out of that point source's sphere of influence. In the analysis presented in this Chapter, variations in exposure levels result from travel away from the residence by commuting to work, shopping, or traveling for personal business. Although the estimates given here improve our understanding of expected exposures to individuals in the vicinity of sources, they do not help in understanding how overlapping. sources might affect individual exposures. For example, Houston, Texas, has six chemical manufacturing facilities, five petroleum refineries, and one coke oven. Without atmospheric monitoring data, it is impossible to estimate precise total exposures to individuals in that city. This analysis thus provides a more realistic evaluation of exposures to individuals than is provided by source-specific analysis. Although many assumptions are required, the estimates used in this chapter rely as much as possible on studies of human behavior and on statistical population data. Because individuals generally spend more than 60% of the time at home under the annaal average condition, short-term monitoring data have been combined with annual average estimates to estimate total exposure. Cities with highly directional wind roses or more than one large benzene source may have significantly different conditions from those estimated. In addition, it is assumed that outdoor benzene con- centrations are similar to indoor concentrations. However, no indoor monitoring has been conducted to verify this assumption. Such problems will remain unresolved until much more atmospheric monitoring is conducted. B. Determination of an Individual's Use of Time The first step in estimating total exposure is to determine an individual's use of time. John P. Robinson of the Communication Research Center at Cleveland State University (1977) has extensively researched 118 ------- Americans use of time. For his survey, he required individuals to keep time diaries of the daytime and nightime activities over a 1-month period- a technique whose basic reliability and validity had been established by several earlier methodological studies. A time diary study was conducted for the first time in 1965 and was repeated in 1975 to evaluate changes over the 10-year period. Survey results were presented in terms of the sex, employment, and marital status of those surveyed. Because we were interested in estimating the amount of time spent away from the residence, we needed data for those employed full-time. The results for employed men shown in Table X-l provide the best measure of that. No reliable data were available for employed women. (Part-time female workers were included in the statistics for employed women in Robinson's study, thus tending to bias the results.) Table X-l PERCENTAGE OF TIME SPENT PER WEEK IN MAJOR TYPES OF ACTIVITIES BY EMPLOYED MEN IN URBAN AREAS, 1975 Activity % of Time per Week Sleep 32% Work for pay 26 Family care 6 Personal care 12 Leisure (total) 24 Organizations 2.5 Media 11 Social life 4.5 Recreation 2 Other leisure 4 Source: Robinson (1977). 119 ------- To estimate commute time, travel time for personal business, and shopping time, the activities contained within each major activity shown in Table X-l must be clearly understood. "Work for pay" includes all work, plus breaks, and commuting. "Family care" includes shopping, house- work, child care, and helping others. "Personal care" includes all hygiene, meals, and travel associated with family and personal care. The time spent on adult education and organized activity, including religion, are part of the "organizations" category. "Media" includes radio, television, reading, and movies. "Social life" includes the time spent on entertainment, social visits, and conversation. "Recreation" includes sports, outdoor activities, and walking. The "other leisure" category includes hobbies, records, letters, resting and relaxing, and all leisure travel. Estimates of commuting time were obtained from the Nationwide Personal Transportation Survey conducted by the Federal Highway Adminis- tration (Department of Transportation, 1973). As shown in Table X-2, commute time from home to work was reported in terms of population by place of residence. The average for incorporated localities was 21 minutes. Assuming two weeks of vacation per year, individuals spend 2% of their time per year commuting. For an upper limit, those living in incorporated areas with populations exceeding 1,000,000 spent 3% of their time commuting. If the limitations of the available monitoring data are considered, an individual is assumed to be exposed to similar levels of benzene whether commuting to work during rush hour or driving on freeways at other times. As a result, the times estimated.for each of these activities were combined into one category. Available surveys lack specificity in regard to shopping or to driving a car for nonwork activities. Consequently, we developed best- judgment estimates of the percentages of time that could be attributed to these activities. Visits to rural areas for vacation or other leisure activities were estimated to range from 2 to 4% of time spent. The amount of time spent shopping in suburban locations or downtown areas 120 ------- Table X-2 PERCENT OF THOSE EMPLOYED BY PLACE OF RESIDENCE AND COMMUTING TIME TO WORK Population Place of Residence Unincorporated areas Incorporated areas Less than 5,000 5,000 - 24,999 25,000 - 49,999 50,000 - 99,999 100,000 - 999,999 1,000,000 and above All incorporated places All areas and places Home-to-Work 15 & less 50.9 60.3 58.4 61.1 56.4 51.3 28.5 53.2 52.5 16-25 19.1 16.8 16.2 17.1 21.5 22.8 18.5 19.0 19.1 Commuting Time (min) 26-35 13.1 12.9 13.3 11.8 10.7 16.0 20.5 14.4 14.0 36 & more 16.7 10.0 12.1 10.0 11.4 9.9 32.5 13.4 14.4 All 100.0 100.0 100.0 100.0 100.0 100.0 100.00 100.0 100.0 Average for all Workers (min) 23 18 19 19 20 21 32 21 22 Does not include workers that work at home or at no fixed address. Source: Department of Transportation, Federal Highway Administration, 1973. ------- was estimated at 2 to 3% and was assumed to be distributed equally between the two locations. The results of this analysis are shown in Table X-3. Nine scenarios describe most of the possible combinations for residing and working in one of three locations: vicinity of source, suburb, or central city. Place of residence and place of work are the same if an individual works near his/her residence, goes to school, does not work, is retired, or is an invalid. Therefore, "work" can loosely be defined as daytime location. C. Distribution Into Population Subgroups Although the precise number of people maintaining a particular life style in the vicinity of each source or in an urban area cannot be accurately established, reasonable estimates can be made by grouping those individuals into scenarios that represent common living patterns (as shown in Table X-3). The next step toward estimating total exposures is to determine the percentage of the exposed population that can be assigned to each scenario. A first-cut assignment is made by determining the percentage of the population that stays at or near home the majority of the time. Census data indicate that 48% of the population is likely to be in school (elementary; junior high, and high school), or retired (65 and older). The labor force distribution for 1974 shows that another 14% of the total population, that is those between the ages of 20 and 65, does not work. Therefore, roughly 60% are constantly in the vicinity of their homes. The remaining 40% of the population are assumed to work in the vicinity of their homes or to commute to other locations. The results of this analysis are shown in Table X-4. Best judgment was used to develop these percentages. Very few quantitative data are available to estimate the commuting behavior of people. In this analysis, only 20% of those individuals re- siding in central cities are assumed to commute outside those areas to work. Working individuals residing in suburban areas are assumed to commute outside those areas for work. On the other hand, those living 122 ------- Table X-3 ESTIMATED ANNUAL DISTRIBUTION OF TIME SPENT IN VARIOUS ACTIVITIES AND LOCATIONS to Percentage of Time Spent Scenario Reside Vicinity of source* Vicinity of source Vicinity of source Suburb Suburb Suburb Central city Central city Central city Work Vicinity of source Suburb Central city Suburb Vicinity of source Central city Central city Vicinity of source Suburb Commute/ Freeway 1 4 4 1 4 4 1 4 4 Central City 1 2 26 1 3 27 96 68 68 Suburb 1 26 2 94 65 65 1 2 26 Vicinity* of Source Rural 93 4 64 4 64 4 + 4 24 4 + 4 + 2 24 2 + 2 Total % Time Spent 100% 100 100 100 100 100 100 100 100 Source indicates chemical manufacturing facilities, coke ovens, and petroleum refineries. Assumed to be less than 1%. Source: SRI estimates. ------- Table X-4 DISTRIBUTION OF THE POPULATION INTO GROUPS AFFECTED BY OTHER BENZENE EXPOSURE SETTINGS Scenario Reside Vicinity of source Vicinity of source Vicinity of source Total-Source Work' Vicinity of source Suburb Central city % of Population 65 10 25 100 Suburb Suburb Suburb Total-Suburb Suburb Vicinity of source Central city 70 5 25 100 Central city Central city Central city Total- Central city Central city Vicinity of source Suburb 80 5 15 100 Source: SRI estimates. 124 ------- in the vicinity of coke ovens, chemical plants, or petroleum refineries, may already be situated in either a suburban or a central city area. Thus, in this analysis, it is assumed that they travel, shop, and/or commute to areas outside the sphere of influence of the facility. The fact that some of these facilities are in remote areas was not specifically considered in this analysis. D. Selection of Applicable Exposure Data Monitoring data have been collected in an attempt to characterize benzene concentrations near such locations as freeways, intersections, and central city areas. At the request of EPA, Battelle (1978b) collected atmospheric monitoring data for Celumbus, Ohio, in suburbs, in central city areas, and during peak commute periods. The results of their study are shown in Table X-5. The 23-hour average for Site 1 in the central city was 3.9 ppb, whereas the daytime average was 4.4 ppb. This site was described as a midtown intersection with a high traffic load throughout normal business hours. Site 2 was located adjacent to a major commuting highway leading into the business district. Grab samples taken during peak volume traffic gave an average of 6.4 ppb. The average concentration of four 8-hour samples at Site 2 was 4.1 ppb, and the daytime average * was 5. Site 3 was located in a residential neighborhood approximately 1 mile from the central business district with a low service station density and no other major known stationary sources of benzene. The 24-hour average benzene concentration measured at Site 3 was 1.5 ppb. The city of Columbus measured traffic volume at Site 2 during the atmospheric monitoring (see Table X-6). The density of traffic flow in (cars/liter sampled) appears to be correlated with the measured benzene concentrations at the monitoring site on the same side of the highway (n = 8, r = 0.82). The consistently lower density on the eastbound side * Two other 8-hour samples and three grab samples were lost at this location, thereby making these data statistically open to question. 125 ------- Table X-5 RESULTS OF BATTELLE ATMOSPHERIC MONITORING STUDY CT) Site* No. 3 3 3 3 2a 2a 2a 2a 2b 2b 2b 2b 1 1 1 1 * Kev. Trap No. 54 260 3 8 95 143 129 209 6 175 130 39 148 100 20 70 Sampling Period Date 3/15 3/15 3/15 3/15-3/16 3/15 3/15 3/15 3/16 3/15 3/15 3/15 3/15-3/16 3/15 3/15 3/15 3/15-3/16 Start 6:45 AM 2:16 PM 2:11 PM 9:57 PM 7:43 AM 7:43 AM 3:28 PM 6:58 AM 8:12 AM 3:42 FM 3:42 PM 11:20 PM 7:12 AM 3:01 PM 2:55 PM 10:37 PM Finish 2:16 PM 9:57 PM 9:57 PM 8:04 AM 9:45 AM 3:28 PM 5:54 PM 9:01 AM 3:42 PM 5:59 PM 11:20 PM 9:07 AM 2:55 PM 10:30 PM 10:30 PM 8:15 AM Barometer, mmHg 29.38 29.38 29.38 29.35 29.38 29.38 29. J8 29.35 29.38 29.38 29.38 29.35 29.38 29.38 29.38 29.35 Temp, F 34-39 35-40 35-40 33-40 33-36 33-40 37-40 32-33 33-40 37-40 37-40 32-37 33-39 37-40 37-40 32-40 Wind Speed Direction 150-350 350-360 350-360 45-360 150 150-350 350-360 330-360 150-350 350-360 350-360 45-360 150-350 350-360 350-360 45-360 m/s 1.66-2.19 1.17-1.95 1.17-1.95 0.86-2.19 1.66-1.87 1.66-2.19 1.45-1.80 1.40-2.19 1.66-2.19 1.45-1.80 1.00-1.95 0.86-2.19 1.66-2.19 1.00-1.95 1.00-1.95 0.86-2.19 (mi/hr) (3.6-4.7) (2.5-4.2) (2.5-4.2) (1.9-4.7) (3.6-4.0) (3.6-4.7) (3.1-3.9) (3.0-4.9) (3.6-4.7) (3.1-3.9) (2.2-4.2) (1.9-4.7) (3.6-4.7) (2.2-4.2) (2.2-4.2) (1.9-4.7) RH 78-61 67-57 67-57 60-75 78 78-61 57-62 77 78-61 57-62 57-67 59-75 87-61 57-67 57-67 59-75 Conditions drizzle, then overcast overcast overcast drizzle, then overcast overcast overcast drizzle, then overcast overcast overcast drizzle, then overcast overcast overcast Benzene Cone 2.0 1.4 1.4 1.3 8.6 7.5 6.9 4.8 3.4 5.3 3.3 2.2 5.1 5.3 2.9 2.4 Site 1 = downtown Columbus, Ohio. Site 2 = near downtown Columbus, Ohio; major commute route; a and b are on opposite sides of the street. Site 3 = suburban residential Columbus, Ohio. Source: Battelle, 1978b, draft report. ------- Table X-6 TRAFFIC VOLUME AND DENSITY DURING BENZENE SAMPLING PERIODS AT SITE 2 N> Trap No. Date 95 3/15 143 3/15 129 3/15 209 3/16 6 3/15 175 3/15 130 3/15 39 3/15-3/16 Sampling Period Start Finish 7:43 AM 9:45 AM 7:43 AM 3:28 PM 3:28 PM 5:54 PM 6:58 AM 9:04 AM 8:12 AM 3:42 PM 3:42 PM 5:59 PM 3:42 PM 11:20 PM 11:20 PM 9:07 AM Volume of Air Sampled («.) One-Way Traffic Sampling Site 2a, 518 East Broad Westbound Traffic (same side of highway as sampler) 3.7 3,868* 10.4 10,832* 4.0 3,870 2.9 4,465 Sampling Site 2b, 547 East Broad Eastbound Traffic (same side of highway as sampler) 13.8 6,799* 4.5 4,082 13.8 7,231 17.7 2,194 Total Traffic Street 5,132* 17,537* 8,402 5,645 Street 16,741* 7,652 13,625 8,352 Density (Cars/Liter sampled) One-Way Traffic Total Traffic Westbound Traffic 1045 1041 968 1540 Eastbound Traffic 493 907 524 124 1387 1686 2100 1947 1213 1700 987 472 Portions of this count were estimated from the following morning's count. Source: City of Columbus, Division of Traffic Engineering, as cited in Battelle draft report (1978b). Cone of Benzene in Air (ppb) 8.6 7.5 6.9 4.8 3.4 5.3 3.3 2.2 ------- may, to a large extent, explain why the sampling stations on that side registered lower readings. As discussed in Chapter VIII, most of the limited atmospheric moni- toring data have been collected in the vicinity of urban areas. Robinson et al. (1973) reported the results of studies measuring hydrocarbon concentrations in the nonurban atmosphere. The measurements taken in the continental United States are shown in Table X-7. They range from 0.3 to 1.1 ppb, with an average of 0.7 ppb. These results appear to be consistent with the widespread nature of benzene emissions and benzene's low atmospheric reactivity. Radian Corporation (1978) monitored ambient benzene in Burnet, Texas, (a rural community) for Shell Oil Corporation. Three 24-hour samples were collected on consecutive days under variable meteorologic conditions. Complete quality control information was unavailable for these data. Measured benzene concentrations ranged from 3 to 4 ppb. The measurements are not consistent with others taken in remote areas. No explanation was offered for these results. Table X-7 BENZENE CONCENTRATIONS IN REMOTE AIR SAMPLES FROM THE CONTINENTAL UNITED STATES State Location Date Benzene Concentration (ppb) California Idaho Idaho Vermont Washington Point Reyes Hells Canyon Sample 1 Sample 2 Moscow Mountain Ground Airborne Camel's Hump Brethway-Gunderson Ground Airborne 12/9/71 11/6/71 7/16/71 9/8/71 8/4/71 0.3 0.8 0.8 0.9 0.8 1.1 0.4 0.5 Source: Washington State University (1971) as cited in Robinson et al. (1973). 128 ------- In the absence of adequate atmospheric monitoring data, dispersion modeling was undertaken to provide approximate estimates of benzene concentrations in the vicinity of specific locations. Chapters III through V describe dispersion modeling analysis and results for three benzene point sources. In Chapter VIII, the Hanna-Gifford dispersion equation was used to estimate average annual benzene concentrations in suburban areas (see Table VIII-5). If a background concentration of 0.5 ppb is included, the estimated concentrations ranged from 0.73 to 2.0 ppb for suburban areas in six large*cities and appear to be reasonably close to the suburban values found in Battelle's atmospheric monitoring study (see Table X-5). The highest benzene concentrations determined by dispersion modeling for a short period were estimated in the vicinity of major intersections. As shown in Table X-8, 8-hour average concentrations ranged from 12 to 28 ppb. Annual average benzene concentrations, however, are similar to those measured by Battelle along a major commuting arterial (Site 2 on Table X-5). The selected benzene exposure settings for determining total exposure are shown in Table X-9. These estimates represent a combination of the best monitoring and modeling data available to date and our best judgment. Although limitations may be involved in using dispersion modeling data in conjunction with monitoring data, the methodology employed in this type of analysis does provide a more realistic evaluation of total exposure to an 4-ndividual. Several additional studies are worth noting. A recent study by Messer Associates, Inc., for the U.S. Department of Transportation (1977) analyzed the health effects of bicycling in an urban environment by studying 10 male subjects bicycling or driving through the streets of Washington, D.C., under systematically varied conditions. No major adverse short-term effects were noted, but the carboxyhemoglobin (COHb) levels measured for the motorist controls were slightly higher than those for the bicyclists. The authors theorized (1) that the carbon monoxide (CO) encountered in traffic slow-downs and intersection delays may have 129 ------- Table X-8 BENZENE CONCENTRATIONS IN THE VICINITY OF MAJOR INTERSECTIONS BASED ON DISPERSION MODELING Number of Lanes 8-Hour Average Benzene Con- Average Annual Benzene Con- City Hartford, CT Denver, CO Waltham, MA Washington, DC Peoria, IL Springfield, IL Oakbrook, IL Location Buckingham St. at Washington St. Colfax Ave. at Colorado Blvd. Moody St. at Carter St. Wisconsin Ave. at Western Ave. Rt. 150 at Scenic Dr. MacArthur Blvd. at S. Grand Ave. Rt. 83 at 22nd St. (main cross 4 x 6 x 4 x 6 x 8 x 7 x 4 x road x road) 4 8 3 6 5 6 4 Distance^ (m) 8 22 24 24 20 22 20 centration (ppb) 28 37 28 . 28 22 12 23 centration (ppb) 6.9 4.7 6.9 6.9 5.3 3.1 5.6 These locations are all signalized intersections. Number of lanes includes turn lanes in all cases. Wind speed is 1 m/s. Distance from nearest roadway to major receptor. Source: Schewe (1977) using the Hot Spot Guideline. ------- u> Table X-9 BENZENE EXPOSURE SETTINGS IN VICINITY OF SPECIFIC LOCATIONS Average Location Major intersections Freeway /peak commute Central city Suburb Source Rural Benzene Concentrations (ppb) 12 - 28 6 - 7 3-4 1-2 Varies by source ND - 1.0 Averaging Time (hr) 8 2-3 24 24- Annual Annual 0.5 - 1 References Dispersion modeling: Schewe (Table X-8) . Monitoring data: Battelle, (Table X-5). Monitoring data: Battelle, (Table X-5). Monitoring data: Battelle, (Table X-5). Dispersion modeling: SRI (Chapter VIII) . Dispersion modeling: SRI (Chapters III, IV, V). , 1977 1978 1978b 1978b Monitoring data: Robinson et al. , 1973 (Table X-7). "Source" means chemical manufacturing facilities, coke ovens, and petroleum refineries. ND = non-detectable ------- more impact on increasing levels of COHb than the low levels of CO encountered by moving bicyclists and motorists while traveling through the study area, and (2) that motorists may be exposed to higher CO levels than bicyclists who have more mobility in heavy traffic. An additional finding indicates that CO levels monitored at the study's permanent air monitoring station were consistently lower than the CO levels encountered by bicyclists and motorists in the study. Another study conducted by Chaney of the University of Michigan (1977) monitored CO concentrations inside a traveling car. Some of the more important findings were (1) peaks in concentration are primarily the result of traffic slowing down as a result of congestion; (2) CO concentration varied from 2 to 50 ppm, depending primarily on the number of stationary or accelerating vehicles close to the monitored vehicle; (3) measurements on 760 vehicles showed a wide variation in CO concen- trations ranging from 0.05 ppm to 45 ppm; and (4) a large proportion of the vehicles monitored produced only a small amount of the total CO, whereas a relatively small number of the total vehicles contributed almost half of the total monitored CO. The results of these two studies indicate the concentrations to which motorists are exposed from automotive-related emissions, including benzene, are higher than measured at permanent atmospheric monitoring stations. Therefore, the use of monitoring data to represent short-term peak exposures from traffic flow may significantly underestimate actual exposures for motorists. E. Summary of Exposures The estimates for total exposure were calculated by the following steps Determine the number of people within each scenario and for each source by multiplying the exposed population (Table 1-1) by the percentages shown in Table X-4. Urban population is broken down into suburban and central city subgroups by assuming that the population exposed to the higher range in 132 ------- Table 1-1 is located in central cities. The population residing near service stations is exposed to.higher overall benzene levels (additive to the estimated urban exposure from automobile emissions). 2. Multiply the percentage of time spent shown in Table X-3 by the mid-range of the applicable benzene exposure settings shown in Table X-9. Sum the values for each scenario., This represents the total exposure in ppb for an individual within each scenario. Table X-10 shows the calculated values for each of the scenarios. 3. Determine ppb-person-years by multiplying the total exposure levels by the number of exposed individuals and by summing the results. Example calculations for two benzene sources are shown in Table X-ll. The total exposure to individuals living in the vicinity of benzene sources is shown in Table X-12. In comparing this table with Table 1-1, several important differences are evident. Urban exposures, for example, now include automobile emissions and gasoline service stations. The other significant change is the redistribution of the people exposed within the first two ranges of benzene concentrations. The' exposure of more than 90% of the people in the lowest range has increased sufficiently to put them into into the second range. The largest change occurred in the urban exposures category and results from summing the exposures from automobile emissions and gasoline service stations. In addition, approximately 37 million people are estimated to use self-service gasoline stations and are estimated to be exposed to 245 ppb at each trip with an annual exposure time of 1.5 hr/yr. This analysis shows that lifestyle patterns affect annual average benzene exposures and that generally the effect is to increase those exposures. This approach appears to be better than a source-specific analysis alone because it combines several urban exposures into one estimate of annual exposure. The current state of the social sciences does not allow a more sophisticated estimate of time spent in certain 133 ------- activities or the number of people conforming to certain living patterns, Nevertheless, a rough approximation of those uncertainties affords a reasonable evaluation of total exposure to individuals residing in the vicinity of sources of atmospheric benzene. 134 ------- Table X-10 ESTIMATE OF TOTAL EXPOSURE FOR EACH SCENARIO Scenario Median Total Exposure (ppb) t Reside Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Vicinity Suburb Suburb Suburb of of of of of of of of of of of of source source source source source source source source source source source source (0.1-1.0) (1-4) (4-10) (> 10) (0.1-1.0) (1-4) (4-10) (> 10) (0.1-1.0), (1-4) (4-10) (> 10) Vicinity Vicinity Vicinity Vicinity Suburb Suburb Suburb Suburb Central Central Central Central Suburb Vicinity Central Work of source (0.1-1.0) of source (1-4) of source (4-10) of source (> 10) city city city city of source"" city Residential 0 2 7 20 0 2 7 20 0 2 7 20 1 1 1 .5 .5 .0 .5 .5 .0 .5 .5 .0 .0 .0 .0 Mixed Activity 0. 2. 6. 19 1. 2. 5. 14 1. 2. 5. 14 1. 1. 1. 6 5 6 1 3 2 5 8 7 1 3 9 ------- Table X-10 (concluded) * t Scenario. Median Total Exposure (ppb) Reside Work " Residential Mixed Activity Central city Central city 3.5 3.5 Central city Vicinity of source' 3.5 3.9 Central city Suburb 3.5 3.0 * Because annual average exposure varies in the vicinity of a source, a separate estimate is made for each range of benzene exposures as shown in parenthesis after applicable scenarios. Source is used to mean chemical manufacturing facilities, coke ovens, and petroleum refineries. Median total exposure is the mid-point of the benzene ranges. Residential exposures are the estimates shown in Table 1-1 and imply that 24 hours of each day are spent in the vicinity of the source. Mixed activity total exposure is the median exposure assuming that some time is spent in other benzene exposure settings. 'A population-weighted exposure of 1.2 ppb was estimated and used to characterize levels in the vicinity of sources. Source: SRI estimates. ------- Table X-ll EXAMPLE CALCULATION OF TOTAL EXPOSURE FOR TWO BENZENE SOURCE CATEGORIES CO % of Reside Work Population Petroleum Refineries Benzene Concentration Range = 0.1-1.0 ppb Vicinity of source Vicinity of source Vicinity of source Suburb Vicnity of source Central city Benzene Concentration Range = 1.1-4.0 ppb Vicinity of source Vicinity of source Vicinity of source Suburb Vicinity of source Central city Total - Petroleum Refineries Urban-Central City Benzene Concentration Range = 1.1-4.0 ppb Central city Central city Central city Vicinity of source Central city Suburb Subtotal - Central city 65 10 25 65 10 25 80 5 15 Estimated Exposed Comparison Exposure Level Population Among Sources (ppb) (106) (106 ppb-person-yr) 0.6 3.25 1.1 0.5 1.5 1.25 2.5 0.002 2.3 0.0003 2.8 0.00075 5.0 3.5 36 3.9 2 3.0 7 45 2.0 0.6 1.9 0.005 0.0007 0.002 4.5 126.0 7.8 21.0 154.8 ------- Table X-ll (concluded) OJ 00 Reside Work % of Population Urban-Suburban Locations Benzene Concentration Range = 0.1-1.0 ppb Suburb Suburb Suburb Subtotal - Suburban Suburb Vicinity of source Central city 70 5 25 Estimated Exposure Level (ppb) 1.1 1.3 1.9 Exposed Population (106) Total - Urban exposures 48 4 17 69 110 Comparison Among Sources (10 ppb-person-yr) 52.8 5.2 32.3 90.3 250.0 Rounded to two significant figures. Source: SRI estimates. ------- Table X-12 SUMMARY OF ESTIMATED TOTAL EXPOSURES OF PEOPLE RESIDING IN THE VICINITY OF ATMOSPHERIC BENZENE SOURCES Vicinity of Residence Number of People Exposed Annual Average Benzene Concentrations (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 > 10.0 Totalt Comparison Among Sourcestt (106 ppb-person-year) Co vO Chemical manufacturing Coke ovens Petroleum refineries Urban areas 3,900,000 3,100,000 200,000 100,000 3,250,000 1,750,000 110,000,000 200,000 80,000 7,300,000 300,000 5,000,000 110,000,000 10.0 0.2 4.5 250.0 The term "total exposures" is used to mean the sum of an individual's exposure to atmospheric benzene from a variety of activities during a year. This assumes that people spend part of their time away from their residence, resulting in exposures to different benzene concentrations depending on their activity (i.e., commuting to work, shopping, traveling on personal business). Nonurban exposures are not included in this analysis but are expected to range from undetectable to 1.0 ppb. Rounded to two significant figures. 'The median values shown in Table X-10 were used for this calculation instead of the mid-point of the ranges. This allows a better comparison with Table 1-1. Source: SRI estimates. ------- BIBLIOGRAPHY American Petroleum Institute, "API Environmental Benzene Range Finding Report-Summer 1977," draft report (1977). Anderson, E.V., "Output of the Top 50 Chemical Drops Sharply," Chemical and Engineering News, pp. 34-37, (May 1976). Applied Urbanetics, Inc. "Market Share Study," FEA Contract No. CO-06- 60435, p. 11-13 (1976). Ayers, G. W., and R. E. Muder, "Benzene," in Kirk-Othemer Encyclopedia of Chemical Technology, A. Stanton (Ed.), 2nd Edition, John Wiley and Sons, Inc., New York, Vol. 3, pp. 367-401 (1964). 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MacKenzie, C. A., Unified Organic Chemistry, Harper and Row, New York pp. 91-97 (1962). Markwordt, D., Emission Standards and Engineering Division, Office of Air Quality Planning and Standards, EPA, personal communication (March 24, 1978). Mascone, D., Emission Standards and Engineering Division, Office of Air Quality Planning and Standards, EPA, personal communication (May 2, 1978). Masek, V., "Benzo(a)pyrene in the Workplace Atmosphere of Coal and Pitch Coking Plants," J. of Occ. Med.. Vol. 13, p. 193-198 (1971). R-3 ------- Matsuura, T. and K. Omura, "Photochemical Hydroxylation of Aromatic Compounds," Synthesis, Vol. 3, pp. 73-184 (1974). McAuliffe, C., "Solubility in Water of C^ to Cg Hydrocarbons," Nature, Vol. 200, No. 4911, pp. 1092-1093 (1963). McGannon, H. E. (Ed.), The Making, Shaping, and Treating of Steel, 9th Edition, U.S. Steel, Pittsburgh, pp. 104-177 (1970). Messer Associates, Inc., "A Study of the Health Effects of Bicycling in an Urban Atmosphere," prepared for U. 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Johnson, Strategies and Air Standards Division, U.S. Environmental Protection Agency, concerning "Use of Dispersion Calculations in Determining Population Exposures to Benzene from Chemical Plants" (September 20, 1977b). , memo to R. J. Johnson, Strategies and Air Standards Division, U.S. Environmental Protection Agency, concerning "Population Exposures to Benzene from Petroleum Refineries and Large Coking Plants" (September 21, 1977c). , memo to R. J. Johnson, Strategies and Air Standards Division, U.S. Environmental Protection Agency, concerning "Ambient Impact of Evaporative Benzene from Service Stations" (February 17, 1977d). , personal communication (January 31, 1978). R-7 ------- APPENDIX A DIAGRAMS OF VARIOUS BENZENE-RELATED OPERATIONS A-l ------- QUENCH I (iG EMISSIONS STASDPIPE CAPS COLLtCTOa MAIN LAHRY CAR WASTE GAS STACK Source: PEDCo, 1977 FIGURE A-1. SCHEMATIC DIAGRAM OF BY-PRODUCT COKE OVEN SHOWING POSSIBLE ATMOSPHERIC EMISSION SOURCES FOR BENZENE ------- AMBIENT EMISSIONS BENZENE 8 o i/i 3 MIXED. ACID H20 .AIR CRUDE NITROBENZENE NITRATOR oc I s t/1 .TO ANILINE PRODUCTION WATER, DILUTE SODIUM CARBONATE WASHER WASH-WATER WASTE SPEND ACID TO RECOVERY o o WASTE NITROBENZENE (REFINED) Source: PEDCo. 1977 FIGURE A-2. FLOW CHART FOR NITROBENZENE MANUFACTURE FROM BENZENE AND NITRIC ACID ------- T -p- ETHYL ENE^ BENZEf< RECYCl AND FRE Q I. « U Q IE E-* SH t OFF-GAS » <;rnilRRINfi SYSTEM 1 | CONDENSER | BENZENE RECYCLE 1 TO REACTOR ETHYLBENZENE c 3 WATER WASH „ CAUSTIC WASH _ uj * ^ . 2 v t *- AND SETTLER AND SETTLER Sf ^f ^5Z i yR .3 o >-ujo 1 p^ f\ 'ALUMINUM •" COMPLEX 1 I HEAVY (POLYETHYL) BENZENES AND TAR RECYCLE (POLYETHYL )BENZENES A1C1. Source: PEDCo, 1977 FIGURE A-3. FLOW CHART FOR ETHYLBENZENE MANUFACTURE FROM BENZENE AND ETHYLENE ------- Ui BENZENE 1 1 HIXFR FUSED c ni T COOLER rnuucDTro CgHg +41/2 ABSORBERS i 1 * VAPOR >m u» rntiinFNTFD .,_.». CUULtK 0, — =— »»CHCO + 2H,0 + 2CO, 2 II > 2 2 CHCO at yz 2 2j sN UACTF MALE 1C ANHYDRIDE Source: PEDCo, 1977 FIGURE A-4. FLOW CHART FOR THE MANUFACTURE OF MALEIC ANHYDRIDE BY CATALYTIC VAPOR-PHASE OXIDATION OF BENZENE ------- I ON FRESH ac 0 f- t_ i u a 1 f 1 i _ a y? a a a p 5 a COMB FEED INED DRUM ~1 CONDENSER f ra ' 1 , & CJ * Ul Ul M Ul CO ^_ BEN; ENE CONDENSER 1 i _. z I c <_ 2 s i i i Q£ 1 ' CUMENE BOTTOMS 1 CONDENSER CUMENE FRESH PROPYLENE PROPANE PROPANE PHOSPHORIC C-H , + CH..CH • CH,.. AC!°.. fcC.H.CHfCH.^- SOLID Source: PEDCo, 1977 FIGURE A-5. PROCESS FOR THE MANUFACTURE OF CUMENE ------- IMPURE CUMENE RECYCLE CUHENE *-*• HYDR06EN- HYDROGENATOR -EMULSIFIERS AIR- SULFURIC ACID- OXIOIZER ACIDIFIER RECYCLE ACID SEPARATOR CHfiH5(CH3)2 + 02 - * CgH5C(CH3)2 OOH — K ACETONE o t 3E £8 •—• O 2 OOH (CHj)2 CO -PHENOL I => i _J . O ACETOPHENONE Source: PEDCo. 1977 FIGURE A-6. FLOW DIAGRAM FOR THE MANUFACTURE OF PHENOL BY THE CUMENE PEROXIDATION PROCESS ------- BENZENE OR — CHLOROBENZENE HYDROCHLORIC ACID, MATER BENZENE, CHLORINE. CO CO § V) CHLORINATOR CD LIT* VENT CO GO SODIUM HYDROXIDE I CHLOROBENZENE HYDROCHLORIC ACID ^ NEUTRALIZING TANK SETTLING. TANK —^DICHLORO- AND POLYCHLOROBENZENES TO DISTILLATION •CgH5C1 + HC1 Hn J. un _ _^ au» i o ni* i OICHLOROBENZENE SLUDGE TO RECOVERY Source: PEDCo. 1977 FIGURE A-7. FLOW DIAGRAM FOR THE MANUFACTURE OF CHLOROBENZENE AND BY-PRODUCT DICHLOROBENZENES ------- RECOVERABLE SOLVENT MIXTURE SETTLING TANK SLUDGE PREHEATER £ = U. UJ ee. a 1/1 O U SODIUM CARBONATE STEAM CONDENSATE T BOTTOMS •WATER OUT •WATER IN DEHYDRATING TANK PRODUCT TO SEWER Source: PEDCo, 1977 FIGURE A-8. TYPICAL SOLVENT RE-REFJNING INSTALLATION A-9 ------- • PRESSURE-VACUUM VENT GAUGE HATCH - MANHOLE Source: PEDCo, 1977 FIGURE A-9. FIXED-ROOF STORAGE TANK •EATHER SHIELD LIQUID LEVEL DRAIN HATCHES VENT ROOF SEAL (NONMETALLIC OR METALLIC) HINGED CENTER SUPPORT MANHOLE Source: PEDCo, 1977 FIGURE A-10. DOUBLE-DECK FLOATING-ROOF STORAGE TANK (Nonmetallic Seal) A-10 ------- ROOF CENTER SUPPORT FLEXIBLE DIAPHRAGM ROOF GAUGE HATCH ROOF SEAL (LIQUID IN TROUGH) Source: PEDCo. 1977 FIGURE A-11. VARIABLE VAPOR SPACE STORAGE TANK (Wet-Seal Lifter Type) A-11 ------- S3 PIPELINE GASOLINE TO STORAGE STORAGE TANK r LOADING VAPORS TO RECOVERY UNIT TERMINAL TRANSPORT VENT GAS 1 VAPOR RECOVERY UNIT RECOVERED <' GASOLINE TO LOADING RACK GASOLINE SOURCE: PEDCo, 1977 FIGURE A-12. VAPOR AND LIQUID FLOW IN A TYPICAL BULK TERMINAL (Floating-Roof Tank) ------- APPENDIX B EMISSION RATES AND POPULATION EXPOSURES FROM CHEMICAL MANUFACTURING FACILITIES B-l ------- Table B-1 EMISSION RATES FROM DIFFERENT CHEMICALS IN EACH PLANT USING BENZENE ESTIMATED EMISSION RATE, JANUARY 1, 1976 (millions of kg per year) STATE ALABAMA CALIFORNIA DELAWARE GEORGIA ILLINOIS LOCATION TUSCALOOSA CARSON EL SEGUNDO RWINDALE RICHMOND SANTA FE SPRINGS DELAWARE CITY CARTERSVILLE BLUE ISLAND CICERO MORRIS SAUGET KANSAS EL DORADO KENTUCKY ASHLAND COMPANY REICHHOLD CHEM.. INC. WITCO CHEM. STD. OIL CO. OF CALIF. SPECIALTY ORGANICS, INC. STD. OIL CO. OF CALIF. FERRO CORP. STO. CHLORINE CHEM CO.. INC. CHEM. PRODUCTS CORP CLARK OIL & REFINING KOPPERS CO.. INC. REICHHOLD CHEM.. INC. MONSANTO SKELLY OIL CO. ASHLAND OIL. INC. LOUISIANA BATON ROUGE FOSTER GRANT CO. CARVILLE COS-MAR, INC. CHALMETTE TENNECO. INC. GEISMAR RUBICON CHEM.. INC. PLAQUEMINE GEORGIA PACIFIC CORP. WELCOME GULF OIL CORP. MARYLAND BALTIMORE CONTINENTAL OIL CO. MASSACHUSETTS MALDEN SOLVENT CHEM. CO.. INC. MICHIGAN MIDLAND DOW CHEMICAL MISSISSIPPI PASCAGDULA FIRST MISSISSIPPI CORP. MISSOURI ST. LOUIS MONSANTO NEVADA HENDERSON MONTROSE CHEM. CORP. OF CAL. NEW JERSEY BOUND BROOK AMERICAN CYANAMID BOUND BROOK UNION CARBIDE ELIZABETH REICHHOLO CHEM.. INC. FORDS TENNECO. INC. GIBBSTOWN E. I. flu PONT KEARNY STD. CHLORINE CHEM. CO. WESTVILLE TEXACO. INC. NITRO • BENZENE 0.031 0.23B 0.427 0.266 0.637 ANILINE ETHYL- BENZENE 0.272 0.202 0.070 0.166 0.166 STYHENE 0.668 0.409 0.367 0.273 MALEIC ANHYDRIDE 0.483 2.610 4.641 1.363 1.16X1 CUMENE 0.011 0.012 0.016 0.040 0.001 0.029 PHENOL O.O68 0.026 0.040 0.043 0.120 0.018 0.068 MONO- CHLORO- BENZENE 0.119 0.182 0.476 0.112 DICHLORO- BENZENE 10- ind P.| 0.080 0.232 0.086 0.111 0.008 0.249 0.060 CYCLO HEXANE DETERGENT ALKYLATE (Uni.r •nd Brcnch) 0.066 0.220 0.216 TOTAL EMISSION HATE 0.066 0.066 0.011 0.080 0.246 0.361 0.086 0X162 0.463 2.610 0.324 0.068 0.040 0.830 0.61) 0.070 0.238 0.120 0.612 0.216 OjOOe 1.17J 0.427 4.641 0.112 0.286 0.066 1.363 1.160 0.637 0.080 0.029 I N5 ------- Table EM (Continued) STATE NEW YORK OHIO PENNSYLVANIA PUERTO RICO TEXAS LOCATION NIAGARA FALLS NIAGARA FALLS NIAGARA FALLS SYRACUSE HAVERHILL BEAVER VALLEY BRIDGEVILLE CLAIRTON FRANKFORD NEVILLE ISLAND PHILADELPHIA GUAYAMA PENUELAS PENUELAS BAYTOWN BEAUMONT BEAUMONT BIG SPRING BORGER CHOCOLATE BAYOU CORPUS CHRISTI CORPUS CHRISTI CORPUS CHRISTI FHEEPOtlT HOUSTON HOUSTON HOUSTON HOUSTON HOUSTON ODESSA OYSTER CREEK PHILLIPS PORT ARTHUR PORT ARTHUR PORT ARTHUR SEADRIFT SWEENEY COMPANY ICC INDUSTRIES. INC. OCCIDENTAL PETROLEUM SOLVENT CHEM. CO. ALLIED CHEM. CORP. UNITED STATES STEEL ARCO/POLYMERS. INC. KOPPERS CO.. INC. UNITED STATES STEEL ALLIED CHEMICAL CORP. UNITED STATES STEEL GULF OIL CORP. PHILLIPS PETROLEUM COMMONWEALTH OIL UNION CARBIDE CORP EXXON CORP E. 1. du PONT UNION OIL CO. OF CALIFORNIA AMERICAN PETROFINA PHILLIPS PETROLEUM MONSANTO COASTAL STATES GAS SUN OIL CO. UNION PACIFIC CORP DOW CHEMICAL ARCO/POLYMERS. INC. JHE CHARTER CO. JOE OIL. INC. THE MERICHEM CO. PETRO-TEX CHEM CORP. EL PASO NATURAL GAS DOW CHEMICAL PHILLIPS PETROLEUM CO. ARCOIPOLYMEHS. INC. GULF OIL CORP TEXACO UNION CARBIDE CORP PHILLIPS PETROLEUM CO. NITRO- BENZENE 0.987 ANILINE ETHYL - BENZENE 0.046 0.012 1 0.026 0.526 0.027 0.009 j ] 1 0.077 0.124 0.086 STYRENE 0.30O 0.060 0.054 1.009 0.067 0.102 0.204 MALEIC ANHYDRIDE 1.450 1.740 2.224 CUMENE 0.051 0.072 0.073 0.016 0-028 0.051 PHENOL 0.090 0.260 0.090 0.227 0.1B2 MONO- CHLORO- BENZENE 0.024 0.038 OICHLORO- BENZENE IO- and P-l 0.077 0.077 CYCLO - HEXANE 0.274 0.585 0.330 0.330 0.280 0.098 0.330 0.182 0.060 0.703 DETERGENT ALKYLATE (Llnaar and Branch) 0.224 TOTAL EMISSION RATE 0.024 0.070 0.115 0.090 0.300 1.450 0.260 1.740 0.325 0.686 0.376 0.162 0.330 0.387 0.280 0.170 0.330 0.524 0.018 0.108 0.182 1.534 0.094 0.009 2.224 0.179 0.182 0.124 0.051 0.050 0.300 0.703 u> ------- Table B-1 (Concluded) STATE LOCATION TEXAS TEXAS CITY TEXAS CITY TEXAS CITY WEST VIRGINIA CHARLESTON FOLLANSBEE MOUNDSVILLE NATRIUM NEW MARTINSVILLE WILLOW ISLAND WASHINGTON ANACORTES KALAMA COMPANY MARATHON OIL CO. MONSANTO STANDARD OIL (INDIANA) UNION CARBIDE CORP KOPPEHS CO.. INC. ALLIED CHEM CORP. PPG INDUSTRIES. INC. MOBAY CHEM CORP. AMERICAN CYANAMIDE STIM5ON LUMBER CO. KALAMA CHEMICAL NITROGEN 0.176 0.427 0.188 ANILINE ETHYL- BENZENE 0.899 0.268 STYHENE 0.886 0.673 MALEIC ANHYDRIDE 0.261 CUMNE 0.021 0.007 PHENOL N.A. 0.026 MONO- CHLORO- BENZENE 0.143 DICHLOBO- BENZENE 10- •» P-l 0.197 CYCLO- HEXANE DETERGENT ALKYLATE ILIrucr «nd Branch) 0.149 TOTAL EMISSION HATE 0.031 1.784 0846 0.149 0.4J6 0.340 0.427 0.189 0.026 N.A. - NOT AVAILABLE SOURCE. SRI ESTIMATES ------- Table B-2 ESTIMATED POPULATION EXPOSED TO BENZENE FROM CHEMICAL MANUFACTURING FACILITIES, BY FACILITY CO I ui State Alabama California Delaware Georgia Illinois Kansas Kentucky Louisiana Maryland Massachusetts Michigan Mississippi Missouri Nevada Location Tuscaloosa Carson El Segundo Irwindale Richmond Santa Fe Springs Delaware City Cartersville Blue Island Cicero Morris Sauget El Dorado Ashland Baton Rouge Carville Chalmette Geismar Plaquemine Welcome Baltimore Maiden Midland Pascagoula St. Louis Henderson Company Reichhold Chemical Witco Chemical Standard Oil of Calif. Specialty Organics Standard Oil of Calif. Ferro Corporation Standard Chlorine Chem. Chemical Products Corp. Clark Oil & Refining Koppers Company Reichold Chemical Monsanto Skelly Oil Company Ashland Oil Foster Grant Company Cos -Mar Tenneco Rubicon Chemical Georgia Pacific Corp. Gulf Oil Corporation Continental Oil Co. Solvent Chemical Co. Dow Chemical First Mississippi Corp. Monsanto Montrose Chemical Corp. Total Benzene Emission Rate 106Kg/yr 0.068 0.055 0.011 0.008 0.245 N.A. 0.351 0.086 0.052 0.483 2.610 0.324 0.058 0.040 0.830 0.611 0.07 0.238 0.120 0.512 0.215 0.008 1.172 0.427 4.641 Population Exposed to Benzene 0.1-1.0 20,000 30,000 400 200 80,000 20,000 7,000 4,000 20,000 90,000 70,000 4,000 20,000 100,000 10,000 5,000 4,000 8,000 10,000 500,000 3,000 70,000 20,000 20,000t 1.1-4.0 500 400 4,000 1,500 200 50 60,000 12,000 14,000 80 - 40,000 700 100 100 400 400 15,000 - 26,000 7,000 400,000 4.1-10.0 - 400 200 - 7,000 4,000 2,000 - - 5,000 500 60 1,000 - 3,000 1,000 100,000 (ppb)* > 10.0 - - - - 700 1,000 - - 1,000 90 - - 900 30 50,000 of California 0.112 10,000 400 ------- Table B-2 (continued) W I State Mew Jersey New York Ohio Pennsylvania Texas Location Bound Brook Bound Brook Elizabeth Fords Cibbstoun Kearny Westville Niagara Falls Niagara Falls Niagara Falls Syracuse Haverhill Beaver Valley Bridgeville Clairton Frankford Neville Island Philadelphia Bay town Beaumont Beaumont Big Spring Borger Chocolate Bayou Corpus Christi Corpus Christi Corpus Christi Freeport Houston Houston Houston Houston Houston Odessa Oyster Creek Phillips Company American Cyanamid Union Carbide Reichhold Chemical Tenneco E. I. du Pont Standard Chlorine Chem. Texaco ICC Industries Occidental Petroleum Solvent Chemical Co. Allied Ch-mical Corp. United States Steel Arco/Polyraers Koppers Company United States Steel Allied Chemical Corp. United States Steel Gulf Oil Corporation Exxon Corporation E. I. du Pont Union Oil Co. of Calif. American Petrofina Phillips Petroleum Monsanto Coastal States Gas Sun Oil Company Union Pacific Corp. Dow Chemical Arco /Polymers The Charter Company Joe Oil The Merichem Company Petro-Tex Chemical El Paso Natural Gas Dow Chemical Phillips Petroleum Co. Total Benzene Emission Rate 106Kg/yr 0.2663 0.068 1.353 1.160 0.637 0.060 0.029 N.A.a 0.024 0.07 0.115 0.09 0.300 1.450 N.A. 0.250 1.740 0.325 0.330 0.9873 0.280 0.170 0.330 0.524 0.0163 0.108 0.182 1.534 0.0943 0.009 N.A. N.A. 2.224 0.179 0.182 N.A. * Population Exposed to Benzene (ppb) 0.1-1.0 70,000 400,000t 400,000 200,000 30,000 3,000 80,000 100,000 3,000 20,000 100,000f 800,000 300,000* 1,000,000 40,000 100,000 30,000 10,000 6,000 100,000 20,000f 1,000,000+ 70,000 1,000 1.1-4.0 3,000 90,000 14,000 7,000 600 - 2,000 5,000 100 700 8,000 30,000 270^000 40,000 5,000 28,000 3,000 1,500 300 6,000 10,000 110,000 6,000 60 4.1-10.0 300 20,000 2,000 900 - - - - - 70 2,000 3,000 30,000 5,000 600 4,000 40 200 30 400 2,000 20,000 100 - > 10.0 8,000 600 200 - - - - - - 600 - 12,000 - - 1,000 - - - - 600 5,000 - - ------- Table B-2 (concluded) W I -vl State Texas (cont'd) Washington West Virginia Puerto Rico Location Port Arthur Port Arthur Port Arthur Seadrift Sweeney Texas City Texas City Texas City Anacortes Kalama Charleston Follansbee Moundsville Natrium New Martinsville Willow Island Guayama Penuelas Penuelas Company Arco/Polymers Gulf Oil Corp. Texaco Union Carbide Corp . Phillips Petroleum Co. Marathon Oil Co. Monsanto Standard Oil (Ind.) Stimson Lumber Co. Kalama Chemical Union Carbide Corp. Koppers Company Allied Chemical PPG Industries Mobay Chemical American Cyanamide Phillips Petroleum Commonwealth Oil Union Carbide Corp. Total Benzene Emission Rate 106Kg/yr 0.124a 0.051 0.50 0.300 0.703 0.0213 1.784 0.846 N.A. 0.025 0.149 N.A. 0.436 0.340 0.427 0.189 0.585 0.3753 0.162 Population 0.1-1.0 50,000 3,000 9,000 20,000 1,000 70,000 20,000 6,000 10,000 3,000 100,000 100,000 Exposed 1.1-4.0 2,000 800 2,000 28,000 - 2,700 2,700 300 2,700 100 17,000 5,000 to Benzene 4.1-10.0 20 200 600 4,000 - _ 300 30 300 - 4,000 600 (ppb)* > 10.0 - - 100 1,000 - _ - - - - _ 80 TOTALS 6,000,000 1,300,000 200,000 80,000 a - When more than one chemical manufacturing facility is located in a city, it is assumed that they are in approximately the same area and the emission levels are summed. Annual average concentrations; to convert to 8-hour worst case, multiply by 25; to convert to ug/m3, multiply by 3.2; a dash (-) signifies that no exposed population was estimated by our method for the average annual concentrations listed. There may be some population exposed to those concentrations for shorter periods of time. Some population may be exposed to annual average concentrations above 0.1 ppb beyond 20 km. 'Totals are rounded to one significant figure. Source: SRI estimates. ------- APPENDIX C POPULATION EXPOSURES FROM COKE-OVEN OPERATIONS BY LOCATION C-l ------- Table Ol ESTIMATED POPULATION EXPOSED TO BENZENE FROM COKE OVENS, BY PLANT LOCATION ^ Locution ALABAMA Tarrant Holt Woodward Gadsden Thomas Birmingham Fairfield CALIFORNIA Fontana COLORADO n Pueblo 1 N> ILLINOIS Granite City Chicago Chicago South Chicago INDIANA Chesterton Indianapolis Terre Haute East Chicago East Chicago Gary Indiana Harbor KENTUCKY Ashland MARYLAND Sparrows Point MICHIGAN Detroit Dearborn Zug Island (Detroit) ^ Plant Name Tarrant Plant Holt Plant Woodward Plant Gadsden Plant Thomas Plant Birmingham Plant Fairfield Plant Fontana Plant Pueblo Plant5 Granite City Steel Div. Chicago Plant Wisconsin Steel Works South Chicago Plant Burns Harbor Plant Prospect Street Plant Terre Haute Plant Plant No. 2 Plant No. 3 Gary Plant Indiana Harbor Plant Semet Sparrows Point Plant Semet Steel Plant Zug Island Plant A Company Alabama By-Product Co. Empire Coke Co. Koppers Company, Inc. Republic Steel Corp. Republic Steel Corp. U.S. Pipe and Foundry Co. U.S. Steel Corp. Kaiser Steel Corp. CF&I Steel Corp. National Steel Corp. Inter lake, Inc. International Harvester Co., Wisconsin Steel Div. Republic Steel Corp. Bethlehem Steel Corp. Citizens Gas & Coke Utility Indiana Gas and Chemical Corp. Inland Steel Co. Inland Steel Co. U.S. Steel Corp. Youngstown Sheet and Tube Co. Solvay Div., Allied Chemical Corp. Bethlehem Steel Corp. Solvay Div., Allied Chemical Corp. Ford Motor Co. Great Lakes Steel Div. , National Steel Corp. Annual Coal Capacity* (tons) 1,200,000 150,000 800,000 820,000 185,000 1,175,000 2,500,000 2,336,000 1,332,000 1,132,000 949,000 991,000 590,000 2,630,000 675,000 204,000 3,102,000 1,642,000 3,700,000 2,100,000 1,600,000 4,820,000 900,000 1,800,000 2,850,000 Emission Ratet (g/sec) 1.0 0.13 0.69 0.71 0.16 1.0 2.2 2.0 1.1 0.97 0.82 0.85 0.51 2.3 0.58 0.18 2.7** 1.4 3.2 1.8 1.4 4.1 0.77 1.5 2.5 Population Exposed^ to Benzene (ppb)T 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 2,000 | - - 480 - 6,250 - 1,420 - - 830 - - - 60 - 21,330 36,860 580 550 19,380 _ 2,200 33,930 ------- Table C-l (continued) o Location MINNESOTA St. Paul Duluth MISSOURI St. Louis NEW YORK Buffalo Lackawana Buffalo OHIO Ironton New Miami Middletown Painesville Portsmouth Toledo Cleveland Mas si Ion Warren Youngs town Lorain Campbell PENNSYLVANIA Swedeland Bethlehem Johnstown Johnstown Midland Aliquippa Pittsburgh Erie Philadelphia Pittsburgh Clairton Fairless Hills Monessen A Plant Name St. Paul Plant Duluth Plant St. Louis Plant Harriet Plant Lackawana Plant § Donner-Hanna Plant Ironton Plant Hamilton Plant Middletown Plant8 Painesville Plant Empire Toledo Plant8 Cleveland Plant Mas si Ion Plant Warren Plant Youngs town Plant Lorain Cuyahoga Works Campbell Plant Alan Wood Plant Bethleham Plant5 Rosedale Div. Franklin Div. Alloy & Stainless Steel Div. Aliquippa Plant§ Pittsburgh Plant Erie Plant Philadelphia Plant Neville Island Plant Clairton Plant5 Fairless Hills Plant Wheeling ^ Company Koppers Company, Inc. U.S. Steel Corp. Great Lakes Carbon Corp., Missouri Coke & Chemical Div. Semet-Solvay Div., Allied Chemical Corp. Bethlehem Steel Corp. Donner-Hanna Coke Corp. Semet-Solvay Div., Allied Chemical Corp. Armco Steel Corp. Armco Steel Corp. Diamond Shamrock Corp. Detroit Steel Div. , of Cyclops Corp. Inter lake Inc. Republic Steel Corp. Republic Steel Corp. Republic Steel Corp. Republic Steel Corp. U.S. Steel Corp. Youngs town Sheet and Tube Co. Alan Wood Steel Co. Bethlehem Steel Corp. Bethlehem Steel Corp. Bethlehem Steel Corp. Crucible Inc., Div. Colt Industries Jones and Laughlin Steel Corp. Jones and Laughlin Steel Corp. Koppers Company, Inc. Philadelphia Coke Division Shenango Inc. U.S. Steel Corp. U.S. Steel Corp. Pittsburgh Steel Corp. Annual Coal Capacity* (tons) 250,000 850,000 450,000 400,000 4,250,000 1,387,000 1,230,000 934,000 748,000 215,000 600,000 438,000 2,220,000 250,000 650,000 1,500,000 2,700,000 2,300,000 803,000 2,210,000 550,000 1,680,000 657,000 2,250,633 2,587,404 290,000 715,400 1,022,000 9, 670,000ft 1,800,000 750,000 Emission Ratet (g/sec) 0.22 0.73 0.39 0.34 3.7 1.2 1.1 0.80 0.64 0.18 0.52 0.38 1.9 0.22 0.56 1.3 2.3 2.0 0.69 1.9 0.47** 1.4 0.57 1.9 2.2 0.25 0.61 0.88 8.3 1.5 0.65 Population Exposed'*' to Benzene (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 - - - - 20,250 3,720 2,370 10 — - — - 5,760 - - 1,990 2,870 4,070 - 5,550 2,680 - - 10,170 - 2,430 — 102,990 4,130 - ------- Table C-l (concluded) n Location TENNESSEE Chattanooga TEXAS Houston Lone Star UTAH Provo WEST VIRGINIA Weirton Weirton Fairmont Follansbee WISCONSIN Milwaukee Plant Name* Chattanooga Plant Houston Plant E. B. Germany Plant Geneva Works $ Weirton Mainland Plant Weirton' s Brown's Island Plant Fairmont Plant East Steubenville Plant Milwaukee Solvay Coke Co. Company* Chattanooga Coke and Chemicals Co. Armco Steel Corp. Lone Star Steel Co. U.S. Steel Corp. Weirton Steel Div., National Steel Corp. Weirton Steej. Div., National Steel Corp. Sharon Steel Corp. Wheeling-Pittsburgh Steel Corp. A Division of Picklands Mather and Co. Annual Coal Capacity* (tons) 204,400 584,000 498,000 2,000,000 2,500,000 1,825,000 300,000 2,500,000 347,000 TOTAL1"* Emission j. Rate* Population Exposed to Benzene (ppb^ (g/sec) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 0.18 0.50 0.43 1.7 20 2.2** 1.6 0.26 2.2 3 0.30 300,000 Keystone Coal Industries Manual (1975) and Varga (1974), as cited in Suta (1977). SRI estimates; population estimates are based on detailed census tract information available from Suta (1977). ^Annual average concentrations; to convert to 8-hour worst case, multiply by 25; to convert to yg/m3, multiply by 3.2. A dash (-) indicates that no exposed population was estimated by our method for those annual average concentrations listed. There may be some population exposed to those concentrations for shorter periods of time. § Coke oven operations producing benzene as a by-product (PEDCo, 1977). t* Coke oven operations located in approximately the same place. Their emission rates are summed. tt tt. Total is rounded to one significant figure. Based on a 1973 emission inventory. ------- APPENDIX D POPULATION EXPOSURES FROM PETROLEUM REFINERIES BY LOCATION D-l ------- Table D-l ESTIMATED POPULATION EXPOSED TO BENZENE FROM PETROLEUM REFINERIES BY PLANT LOCATION Location1 ALABAMA Holt Warrior Asphalt Co. of Alabama, Inc. Theodore Marion Oil Co. Tuscaloosa Hunt Oil Co. o Total N) ALASKA Kenai Chevron USA Inc. Tesoro Petro Corp. North Slope At-Rich Co. Total ARIZONA Fredonia Arizona Fuels Corp. Total Total Capacity (H^m3)1 .17 1.04 1.65 2.86 1.28 2.21 .75 4.24 .23 .23 Total Emission (106R)2 2.1 13.5 21.5 37.1 16.6 28.7 9.8 55.1 3.0 3.0 Emission Rate Population Exposed2 to Benzene (ppb)* (R/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 , .07 - - .43 - - .68 - - .53a .91 - .31 .10 ARKANSAS El Dorado Lion Oil Co. 2.69 35.0 1.11 1. Source: Oil and Gas Journal, May 28, 1977. 2. Source: SRI estimates. ------- Table D-l (continued) o i to Location1 ARKANSAS (continued) Norphlet MacMillan Ring-Free Oil Co., Inc. Smackover Cross Oil & Refining Co. of Arkansas Stephens Crystal Oil Co. Total CALIFORNIA Bakersfield Chevron USA Inc. Kern Co. Refinery Co. Lion Oil Co. (TOSCO) Mohawk Petroleum Corp., Inc. Road Oil Sales Sabre Refining Co. Sunland Refining Co. West Coast Oil Co. Benicia Exxon Co. Carson ^ Atlantic-Richfield Fletcher Oil and Refining Co. Total Capacity (IP6!!!3)1 .26 Total Emission (106g)2 3.3 .34 .22 3.51 1.51 .92 2.21 1.28 .09 .20 .81 .87 5.12 10.165 1.11 4.4 2.9 45.6 19.6 12.0 28.7 16.7 1.1 2.6 10.6 11.3 66.4 312.2 14.5 Emission Rate (g/sec)2 .11 .14 .09 .62a .38 .91 .53 .04 .08 .34 .36 2.11 9,9ia .46 Population Exposed2 to Benzene (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 400 70,000 ------- Table D-l (continued) Location* CALIFORNIA (continued) El Segundo Chevron USA Inc. Hanf ord Beacon Oil Co. Hercules Pacific Refining Co. Long Beach Edgington Oil Co. Inc. Los Angeles Union Oil Co. - Calif. Martinez Lion Oil Co. (TOSCO) Shell Oil Co. Newhall Newhall Refining Co. Inc. Oildale Golden Bear Div. , Witco. Chemical Corp. San Joaquin Refining Co. Oxnard Oxnard Refinery Paramount Douglas Oil Co. Richmond AA Shell Oil Co. San Francisco Union Oil Co. - Calif. Total Capacity (lOSi3)1 c 23.51s .71 3.09 1.71 6.27 7.31 5.80 .63 .61 1.57 .15 2.70 21.20 6.44 Total Emission (106g)2 702.5 9.3 40.2 22.3 81.5 95.1 75.4 8.2 7.9 20.4 1.9 35.1 550.8 83.8 Emission A Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 t 22.30 60,900 - .29 1.28 ~ - .71 2.59 - - - - 3.02a 2.40 500 .26 .25a .65 - .06 1.11 - 17.49 100,000 - 2.66 - ------- Table D-l (continued) Location Emission Rate Population Exposed to Benzene (ppb) i Ul CALIFORNIA (continued) Santa Fe Springs Gulf Oil Co. Powerline Oil Co. Santa Maria Douglas Oil Co. Signal Hill MacMillan Ring-Free Oil Co. South Gate Lunday-Thagard Oil Co. Torrance Mobile Oil Corp. Ventura USA Petrochem Corp. Wilmington Champlin Petroleum Co. Shell Oil Co. Texaco Inc. Total COLORADO Commerce City Asamera Oil (U.S.) Inc. Denver Continental Oil Co. Fruita Gary Western Co. Total (106m3)* 2.99 2.56 .55 .67 .49 7.17 .87 1.78 5.22 4.35 132.63 1.31 1.89 .53 3.73 (106g)2 38.9 33.3 7.2 8.7 6.4 93.2 11.3 23.1 67.9 56.6 2,576,7 17.0 24.5 6.94 48.44 (g/sec)z 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 1.23a 1.06 - - .23 .28 .20 2.96 400 - .36 .73a 2.16 1.80 200 231,500 .54 - - .78 - .22 ------- Table D-l (continued) Location1 DELAWARE Delaware City Getty Oil Co. Inc. Total Total Total Emission Capacity Emission Rate (106g)2 (g/sec)2 8.13 8.13 105.6 105.6 3.35 Population Exposed2 to Benzene (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 100 100 FLORIDA St Marks Seminole Asphalt Refinery Co. Total .33 .33 4.3 4.3 .14 o GEORGIA o> Douglasville Young Refining Co. Savannah Amoco Oil Co. Total .28 8.71 8.99 3.6 .12 .36 HAWAII Barbers Point Chevron USA Inc. Ewa Beach Hawaii Independent Refinery Inc. Total 2.32 3.42 5.74 30.2 44.5 74.7 .96 1.41 ------- Table D-l (continued) Location1 Total Total Emission Capacity Emission Rate ? Population Exposed to Benzene (ppb) ILLINOIS Blue Island Clark Oil and Refining Co. Colmar Yetter Oil Co. Hartford Clark Oil and Refining Co. Joliet Mobil Oil Corp. Lawrenceville Texaco Inc. Lemont ^ Union Oil Co. of Calif. Lockport Texaco Inc. Plymouth Wireback Oil Co. Inc. Robinson Marathon Oil Co. Wood River Amoco Oil Co.A£ Shell Oil Co. Total CIO6™3)1 3.86 .06 3.03 10.45 4.88 8.76§ 4.18 .10 11.32 5.51 16.43§ 68.58 (106g)2 50.1 .8 39.4 135.8 63.4 294.8 54.3 1.4 147.1 71.7 535.8 1,463.18 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 1.59 - -' .02 - 1.25 - - 4.31 6,000 ^ 2.01 - - 9.36 7,000 - 1.72 - - .04 4.67 400 - 2.283 17.01 IQQ.OQQt - 113,400 ------- Table D-l (continued) 00 Location1 INDIANA East Chicao Energy Coop. Inc. Fort Wayne Gladieux Refinery Inc. Indianapolis Rock Island Refining Corp. Laketon Laketon Asphalt Refining Inc. Mt. Vernon Indiana Farm Bureau Coop. Association Inc. Princeton Princeton Refinery Inc. Whiting Amoco Oil Co. Total KANSAS Arkansas City Apco Oil Co. Augusta Mobil Oil Corp. Chanute Mid Amer Refinery Co. Coffeyville CRA Inc. Total Capacity (106m3)1 7.31 .71 2.53 .47 .12 .27 21.19 33.31 2.68 2.90 .18 2.81 Total Emission (106g)2 95.1 9.2 32.9 6.1 1.6 3.5 275.4 423.8 34.9 37.7 2.3 36.5 Emission ^ Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 3.02 300 - .29 1.04 - .19 .05 .11 - 8.74 4,000 - 4,300 1.11 - 1.20 - .07 1.16 - ------- Table D-l (continued) Location1 KANSAS (continued) El Dorado AA Getty Oil Co. Pester Refining Co. Kansas City Phillips Petroleum Co. McPherson Nat. Coop. Refinery Assoc. Phillipsburg CRA Inc. Shallow Water E-Z Serve Wichita Derby Refining Co. Total KENTUCKY Betsy Layne Ky Oil & Refining Co. Inc. Catlettsburg ^ Ashland Petr. Co. Louisville Louisville Refining Co. Somerset Somerset Refinery Inc. Total Total Capacity 4.57§ 1.31 5.22 3.14 15.32 .55 1.45 40.13 .03 c 7.883 1.46 .17 9.54 Total Emission (106g)2 151.8 17.0 67.9 40.9 199.2 7.2 18.1 613.5 .04 361.0 19.0 2.3 382.34 Emission ^ Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 s 4.82a .54 80 - - 2.16 1.30 6.32 200 .23 - .60 280 .01 - - 11.46 6,000 - .60 - - .07 - 6,000 ------- Table D-l (continued) Location1 o i LOUISIANA Baton Rouge Exxon Co. Belle Chasse Gulf Oil Co., Alliance Refinery** Chalmette Tenneco Oil Co.** Church Point Canal Refining Co. Convent Texaco Cotton Valley Kerr-McGee Refining Corp. Garyville Marathon Oil Co. Hosston Bayou St. Oil Corp. Jennings Evangeline Refining Co. Inc. Lake Charles Cities Service Oil Co. Continental Oil Co. Lisbon Claiborne Gasoline Co. Meraux Murphy Oil Co. Total Total Emission A Capacity Emission Rate Population Exposed2 to Benzene (ppb) (106m3)1 (106g)2 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 200,000f 6,000 2,000 20 200 29.60§ 11.4§ 4.93§ .26 8.13 .64 11.61 .23 .29 15.56§ 4.82 .38 5.37 628.7 353.7 167.0 3.4 105.6 8.30 150.9 3.0 3.8 303.0 62.6 4.9 69.8 19.96 11.23 5.3 .11 3.35 .26 4.79 .10 .12 9.62a 1.99 .16 2.22 6,000 ------- Table D-l (continued) Total Total Emission o i Location1 Capacity Emission Rate Population Exposed to Benzene (ppb) LOUISIANA (continued) Metairie Good Hope Refineries Inc. Norco Shell Oil Co. Port Allen Placid Refining Co. Princeton Calumet Refining Co. Shreveport Atlas Production Co., Div. of Pennzoil** St. James LaJet Inc. Venice Gulf Oil Co. Total MARYLAND Baltimore Amoco Oil Co. Chevron USA Inc. Total MICHIGAN Alma Total Petroleum Inc. (lOV)1 3.86 13.93 1.99 .14 2.61§ .83 1.67 118.25 .87 .78 1.65 (106g)2 50.2 181.1 25.8 1.8 207,3 10.8 21.7 2,363.4 11.3 10.2 21.5 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 1.59 - - 5.75 400 - .82 .06 6,58 30,000 - .34 .69 - 244,620 .36a .32 2.32 30.2 .96 ------- Table D-l (continued) Total Total Emission Capacity Emission Rate Population Exposed2 to Benzene (ppb)' o I—1 CO Location1 MICHIGAN (continued) Bay City Dow Chemical USA Carson City Crystal Refining Co. Detroit Marathon Oil Co. Kalamazoo Lakeside Refining Co. West Branch Osceola Refinery Div. , Texas American Petrochemicals Inc. Total (106m3)"1 1.21§ .36 3.77 .33 .72 8.71 (106g)2 135,5 4.7 49.0 4.2 9.3 212.9 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 4.30 6,000 - .15 1.56 - - .13 .30 6,000 MINNESOTA Rosemount Koch Refining Co. St. Paul Park Northwest Refining Co., of Ashland Oil Co. Wrenshall Continental Oil Co. Total MISSISSIPPI Lumberton Southland Oil Co. Pascagoula Div. 7.39 3.83 1.36 12.58 96.1 49.8 17.7 163.6 3.05 1.58 .56 10 10 Chevron USA Inc. ** .33 4.3 16.3 422.5 .14 13.41 30,000 ------- Table D-l (continued) Total Total Emission . Capacity Emission Rate Population Exposed2 to Benzene (ppb)' o i Location1 MISSISSIPPI (continued) Purvis Amerada-Hess Corp. Sandersville Southland Oil Co. Yazoo City Southland Oil Co. Total MISSOURI Sugar Creek Amoco Oil Co. Total MONTANA Billings Continental Oil Co. Exxon Co. Cut Bank Westco Refining Co. Great Falls Phillips Petroleum Co. Kevin Big West Oil Co. Laurel Cenex Wolf Point Tesoro Petroleum Corp. Total (ib6™3)'1 1.65 .60 .23 19.11 6.21 6.21 3.05 2.61 .27 .35 .30 2.35 .15 9.08 (106g)2 21.5 7.85 3.0 459.2 80.7 80.7 39.6 34.0 3.5 4.5 3.87 30.5 1.9 117.87 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .68 .25 - - .10 30,000 2.56 - 1.26a 1.08 ~ .11 - - .14 .12 .97 - .06 ------- Table D-l (continued) o i Location1 NEBRASKA Scottsbluff CRA Inc. Total NEW HAMPSHIRE Newington Atlantic Terminal Corp. Total NEW JERSEY Bayonne National Oil Recovery Corp. Linden Exxon Co . Paulsboro Mobil Oil Corp. Perth Amboy Chevron USA Inc. Westville Texaco, Inc. Total NEW MEXICO Artesia Navajo Refining Co. Bloomfield Plateau Inc. Thriftway Co. Total Capacity (lOV)1 .29 .29 .75 .75 .35 16.54 5.69 9.75 5.12§ 37.45 1.74 .49 .44 Total Emission (106g)2 3.8 3.8 9.8 9.8 4.5 215.0 73.9 126.8 179.6 599.8 22.6 6.3 5.7 Emission ^ Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .12 - - .31 .14 6.83 40,000 - 2.35 4.02 7,000 - 5.7 4,000 - 51,000 .72 .20a .18 Ciniza Shell Oil Co. 1.04 13.6 .43 ------- Table D-l (continued) a i i-1 Wn Location1 NEW MEXICO (continued) Farmington Giant Refining Co. Inc. Kirtland Caribou Four Corners Inc. Loving ton Southern Union Refining Co. Monument Southern Union Refining Co. Total NEW YORK Buffalo Mobil Oil Corp. N. Tonawanda Ashland Petroleum Total NORTH DAKOTA Dickson Northland Oil & Refining Co. Mandan Amoco Oil Co. Willis ton Westland Oil Co. Total Total Capacity .51 .17 2,23 .30 6.92 2.50 3.71§ 6.21 .29 2.84 .27 3.40 Total Emission (106g)2 6.6 2.2 29.0 3.9 96.82 32.4 187,7 220. 1 3.8 37.0 3.5 44.30 Emission Rate Population Exposed2 to Benzene (ppb)* (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .21 .07 - - .92 T. .12 1.03 - - 5,96 20,000 - 20,000 .12 1.17 „ - - _ .11 ------- Table D-l (continued) Total Total Emission Capacity Emission Rate Population Exposed to Benzene (ppb) o i Location OHIO Canton Ashland Petroleum Co. Cleves Gulf Oil Co. Findlay Ashland Petroleum Co. Lima Standard Oil Co. of Ohio Toledo Gulf Oil Co. Standard Oil Co. of Ohio Sun Petroleum Prod. Co. Total OKLAHOMA Ardmore Vickers Petroleum Corp. Arnett Tonkawa Refining Co. Gushing Hudson Refining Co. Inc. Cyril Apco Oil Corp. Duncan Sun Petroleum Products Inc. Enid Champlin Petroleum Co. (lO6!!!3)1 3.71 2.48 1.16 9.75 2.92 6.96 7.26§ 34.24 3.56 .35 1.10 .81 2.81 3.12 (106g)2 48.3 32.2 15.1 126.8 38.0 90.5 222.1 573. Q 46.2 4.52 14.3 10.6 36.6 40.6 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 1.53 - - 1.02 - .48 - 4.02 4,000 -r 1.20a 2.87 7.05 300,000 - 304,000 1.47 - .14 .46 - - .33 1.16 - 1.29 - ------- Table D-l (continued) Location1 OKLAHOMA (continued) Okmulgee OKC Refining Co. Ponca City Continental Oil Co. Stroud Allied Materials Corp. Tulsa .. ** Sun Petroleum Products Inc. West Tulsa Texaco Inc . Wynnewood Kerr-McGee Corp. Total OREGON Portland Chevron USA Inc. Total Total Capacity (106m3) 1 1.45 7.31 .03 5.14§ 2.90 2.90 31.48 .81 .81 Total Emission (106g)2 18.9 95.1 3.6 175.5 37.7 37.7 521.32 10.6 10.6 Emission Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .60 - - 3.02 100 - .11 5.57 8,000 - - - 1.20 - - 1.20 8,100 .34 PENNSYLVANIA Bradford Kendall-Amalie Dlv., Witco Chemical Co. Emlenton Quaker State Oil Refining Corp. Farmers Valley Quaker State Oil Refining Corp. .52 6.8 .19 2.5 .38 4.9 .22 .98 .16 ------- Table D-l (continued) Location1 PENNSYLVANIA (continued) Freedom Valvoline Oil Co. Div. of Ashland Oil Co. Marcus Hook BP Oil Corp. ^ Sun Petroleum Products Co. Philadelphia AA Atlantic-Richfield Co. D Gulf Oil Co.** ,L Reno 00 Pennzoil Co. - Wolf's Head Div. Roseville Pennzoil Co. - Wolf's Head Div. Warren United Refining Co. Total TENNESSEE Memphis Delta Refining Co. Total Total Capacity (lO6™3)1 .39 9.34§ 9.58§ 10.74 11.855 .12 .58 3.02 46.71 2.55 2.55 Total Emission (106g)2 5.1 138.0 304.0 279.2 397.8 1.6 7.5 39.2 1,186.6 2.3 2.3 Emission A Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0. >10.0 .16 4t38a 9.65 40,000 - a 8.86 12,63 2,000,000"*" - .05 - - .24 1.25 - - 2,040,000. 1.05 - - TEXAS Abilene Pride Refining Co. 2.12 27.5 .87 ------- Table D-l (continued) Location1 Total Total Emission Capacity Emission Rate Population Exposed2 to Benzene (ppb) o >—• vo TEXAS (continued) Amarillo Texaco Inc. Baytown Exxon Co. Beaumont Mobile Oil Corp. Union Oil Co. of Calif. Big Spring ^ Cosden Oil & Chemical Co. Borger Phillips Petroleum Co. Carrizo Springs Tesoro Petroleum Corp. Corpus Christi Champlin Petroleum Corp. Coastal States Petrochemical Co. Howe11 Corp. Quintana Refining Co. Saber Refining Co. Southwestern Refining Co. Inc.** Sun Petroleum Products Co. Deer Park Ajt Shell Oil Co. El Paso ^A Chevron USA Inc. Texaco Inc. ** (lO6!!!3)1 1.16 22.6 18.86§ 6.96 3.77§ 5.80 1.51 7.26§ 10. 7§ 1.23§ 1.36§ .54 6.96§ 3.31§ 17.06§ A. 00 .99 (106g)2 15.1 294.3 550.0 181.1 285.1 75.5 19.7 211.7 449.5 142.4 145.8 7.0 220.8 178.6 648.9 105.6 12.8 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .48 - 9.34 40,000 _. ,. - 17. 46s- 5.75 100,000f „.. _ - 9.05 30,000 _ _ _ 2.40 .63 - 6,72a 14.27 4.52 4.63 .22 7..01 5.67 200,000f 2,000 20.6 2Q,OOOt - 3.35 .41 1,000 - - - ------- Table D-l (continued) Total Total Emission o i Location1 TEXAS (continued) Euless Texas Asphalt Refining Co. Ft. Worth Winston Refining Co. Hearne Mid-Tex Refinery Houston ^fi Atlantic Richfield Co. Charter International Oil Co. Crown Central Petroleum Co.** Eddy Refining Co. LaBlanca Crystal Oil Co. Longview Crystal Oil Co. Mt. Pleasant American Petrofina Inc. Nixon Pioneer Refining Odessa Shell Oil Co. Port Arthur ** American Petrofina Inc. Gulf Oil Co.** Texaco Inc. ** Capacity Emission Rate Population Exposed2 to Benzene (ppb) (106m3)l (106g)2 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .35 1.16 .17 17.76s 3.77§ 5.80 .18 .28 .50 1.51 .15 1.86§ 6.38§ 18.11s 23.56 4.5 15.1 2.3 682.2 68.4 150.9 2.3 3.6 6.5 19.6 1.9 51.3 242,9 630.6 306.3 .14 .48 .07 21,66a 2.17 4.79 .73 .11 .20 .63 .06 1.63 7.71a 20. .02 9.72 l.OOO.OOO1 80,000f 600 ------- Table D-l (continued) 0 I Location1 TEXAS (continued) Quitman Gulf St. Oil & Refining Co. San Antonio Flint Chemical Co. Howell Corp. Silsbee South Hampton Co. Sunray Diamond Shamrock Corp. Sweeny Phillips Petroleum Co. Texas City Amoco Oil Co. Marathon Oil Co.** Texas City Refining Inc. Three Rivers Sigmor Refining Co. Tucker J&W Refining Inc. Tyler LaGloria Oil & Gas Co. White Deer Dorchester Gas Products Co. Winnie JL Jf Independent Refining Co. Young County Thriftway Inc. Total Total Capacity .24 .07 .20 1.05 2.99 6.04 20. 20$ 3.83§ 4.32 .59 .58 1.70 .06 .77 .06 243.22 Total Emission (106g)2 3.1 0.9 2.6 13.7 38.9 102.4 561.0 102,7 56.2 7.7 7.5 22.1 .8 19.9 .8 6,435.6 Emission Rate Population Exposed2 to Benzene (ppb) (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 .10 .03a .08 - - .43 1.23 ,.. 3,25 10 - 17,81a 3.26 1.78 60,000+ - .24 .24 - - .70 .02 .63 .02 - - 1,531,010 2,600 ------- Table D-l (continued) o i NJ N> Location1 Total Capacity (lO6!!!3)1 UTAH Asphalt Ridge Arizona Fuels Corp. North Salt Lake Husky Oil Co. Roosevelt Plateau Inc. Salt Lake City Amoco Oil Co. Chevron USA Woods Cross Caribou Four Corners Inc. Morrison Petroleum Co. Phillips Petroleum Co. Western Refining Co. Inc. Total Total Emission (106g)2 Emission Rate (g/sec)2 .06 1.33 .46 2.26 2.61 .41 .15 1.33 .57 0.8 17.4 6.0 29.4 34.0 5.4 1.9 17.4 7.4 .02 .55 .19 .93a 1.08 .17a .06 .55 .23 Population Exposed2 to Benzene (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 9.18 119.7 VIRGINIA Yorktown Amoco Oil Co. Total WASHINGTON Anacortes Shell Oil Co. Texaco Inc. Ferndale Atlantic Richfield Co. Mobil Oil Corp. 3.08 3.08 5.28 4.53 5.57 4.15 40.0 40.0 68.7 58.9 72.4 53.9 1.27 2.18a 1.87 2.30a 1.71 40 40 ------- Table D-l (continued) OJ Location 1 WASHINGTON (continued) Seattle Chevron USA Tacoma Sound Refining Co. U.S. Oil and Refining Co. Total WEST VIRGINIA Falling Rock Pennzoil Co., Elk Refining Div. Newell Quaker State Oil Refining Corp. St. Marys Quaker State Oil Refining Corp. Total Total Total Emission Capacity Emission Rate (106m3)1 (106g)2 (g/sec)2 .26 .26 1.24 21.29 .28 .56 .28 1.12 3.4 3.40 16.1 276.8 3.7 7.3 3.7 14.7 .11 .51 .12 .23 .12 Population Exposed2 to Benzene (ppb) 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 80 WISCONSIN Superior Murphy Oil Corp. Total 2.64 2.64 34.3 34.3 1.09 WYOMING Casper Amoco Oil Co. Little American Refining Co. Texaco Inc. 2.50 1.42 1.22 32.4 18.5 15.8 1.03a .59 .50 ------- Table D-l (continued) Location1 WYOMING (continued) Cheyenne Husky Oil Co. Cody Husky Oil Co. Cowley Sage Creek Refining Co. LaBarge Mountaineer Refining Co. Inc. Southwestern Refining Co. Lusk C&H Refinery Inc. Newcastle Tesoro Petroleum Corp. Osage Glacier Park Co. Sinclair Sinclair Oil Corp. Total Total Total , O Capacity Emission Rate Population Exposed to Benzene (ppb) (106g)2 (g/sec)2 0.1-1.0 1.1-4.0 4.1-10.0 >10.0 1.37 .63 .07 .02 .03 .01 .61 .24 2.84 17.8 8.1 .86 .23 .4 .14 7.92 3.09 37.0 .57 .26 .03 .007a .01 .005 .25 .10 1.17 10.96 142.24 Total Exposed Populationf 4,000,000 a - When more than one refinery is located in a city, it is assumed that they are in approximately the same area and the emission levels are summed. * 3 To convert to yg/m3, multiply concentrations by 3.2; to convert to 8-hour worst case, multiply by 25. A dash (-) signifies that no exposed population was estimated by our method for those annual average concentrations listed. There may be some population exposed to those concentrations for shorter periods of time. ** Refineries having catalytic reforming of benzene (Oil & Gas Journal, May 28, 1977). Their emission rate is assumed to be twice that of refineries with no benzene production. ------- Table D-l (concluded) o i N> Ol Some population may be exposed to annual average concentrations >0.1 ppb beyond 20 km. ^Rounded to one significant figure. Refineries handling pure benzene (SRI estimates). Emissions from storaee and loading of pure benzene were estimated and added to the process emissions from the refinery. If benzene was used captively at the refinery, no loading emissions were assumed. Controlled emissions were assumed for some refineries where information was available (Brothers, personal communication, 1978). ------- APPENDIX E PARTIAL LIST OF HYDROCARBONS AND ADDITIVES CONTAINED IN GASOLINE E-l ------- Table E-l HYDROCARBONS CONTAINED IN THE VAPOR PHASE OF GASOLINE Methane Ethane Ethylene Propylene Propane Isobutane Isobutylene; Butene N-Butane T-2-Butene C-2-Butene 3-Me-l-Butene Isopentane 1-Pentene 2-Me-l-Butene 2-Me-l, 3-Butadiene N-Pentane T-2-Pentene C-2-Pentene 2-Me-2-Butene 2,2-DimethyIbutane Cyclopentene 3-Me-l-Pentene; 4-Me-l-Pentene 4-Me-C-2-Pentene 2,3-Dimethyl-l-Butene 2-Me-l, 4 Pentadiene Cyclopentane 4-Me-T-2-Pentene 2,3 DimethyIbutane 2-Me-Pentane 2-Me-l-Pentene 3-Me-Pentane; 1-Hexene; 2-Ethyl- C-3-Hexene T-3-Hexene 3-Me-Cyclopentene 2-Me-2-Pentene 3-Me-T-2-Pentene N-Hexane 4,4-Dimethyl-l-Pentene T-2-Hexene C-2-Hexene 3-Me-C-2 Pentene 4-4-Dimethyl-T-2-Pentene Me-Cyclopentane; 3,3-Dimethyl-l-Pentene 2,3-Dimethy1-2-Butene; 2,3,3-Trimethyl-l-Butene 2,4 Dimethylpentane 2,4-Dimethyl-2-Pentene; 3-Ethyl-l-Pentene; 3-Me-1-Hexene Benzene 2,2,3-TrimethyIbutane 2,4-Dimethyl-l-Pentene 4-Dimethyl-C-2-Pentene 1-Me-Cyclopentene 2-Me-C-3-Hexene 2,3-Dimethyl-l-Pentene; 2-Me-3-Hexene 5-Me-1-Hexene; T-3,5-Dimethyl-Cyclopentene; C-3,5-Dimethycyclopentene 3,3-DimethyIpentane Cyclohexane 4-Me-C-2-Hexene 2-Me-Hexane; 5-Me-C-2-Hexene 1,1-Dimethylcyclopentane Cyclohexene 2,3-DimethyIpentane 3,4-Dimethyl-C-2-Pentene 3-M3-Hexane l-C-3-Dimethylcyclopentane; 2-Me-l-Hexene l-T-3-Dimethylcyclopentane 1-Heptene; 2-Ethyl-l-Pentene -1-Butene 3-Ethyle Pentane; 3-Me-T-2-Hexene l-T-2-Dimethylcyclopentane 2,2,4-TrimethyIpentane T-3-Heptene 3-EthyIpentane C-3-Heptene; 1,4-Dimethylcyclopentene 3-Me-C-3-Hexene; 3-Me-T-3-Hexene 3-Ethyl-2-Pentene T-2-Heptene E-2 ------- Table E-l (concluded) N-Heptane; 3-Me-C-2-Hexene 2,3-Dimethyl-2-Pentene 2,3-Dimethylcyclopentene 3—Ethylcyclopentene C-2-Heptene l-C-2-Dimethylcyclopentane 2,2-Dimethyl Hexane Me-Cyclohexane; 1,1,3-Trimethylcyclopentane 2,5-Dimethylhexane Ethylcyclopentane 2,4-Dimethylhexane 2,2,3-Trimethylpentane l-T-C-4-Trimethycyclopentane 3,3-Dimethylhexane Toluene 1-T-2-C-3-Trimethylcyclopentane Ethylbenzene P-Xylene M-Xylene 0-Xylene C-8 Saturates and Olefins Isopropylbenzene N-Propylbenzene l-Me-3-Ethylbenzene l-Me-4-Ethylbenzene l-Me-2-Ethylbenzene 1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene C-9+ Saturates and Olefins l-Me-2-Isopropylbenzene 1,3-Dimethy1-2-Ethylbenzene; 1,3-Diemthy1-4-Ethylbenzene C-10 Saturates and Olefins C-10 + Aromatics Source: Walker et al, 1975, Table IVB. E-3 ------- Table E-2 COMMON ADDITIVES CONTAINED IN GASOLINE DETERGENTS AND ANTI-ICING ADDITIVES Multipurpose Carburetor Detergents Polyoxypropylene Ester and Tallow Trimethylenediamine Naphthenate Alkyl Aryl Phosphate Esters and N-Oleyl-l,3-Propylenediamine Salts Amine-Phosphoric Acid Salt and Olefin Hydrocarbon Phosphate Ester Amine Salts Nitrogen and Phosphorus-Containing Compositions Dimer Acid and N-(10-Phenylstearyl)-l,3-Propylenediamine Succinimides and Long Chain Primary Amines Derivatives of Polymeric Succinimides Polyamine-Alkaryl Carboxylic Acid Reaction Products Nitroketonized Amides Paraffinic Oil Oxidate-Fatty Amide Salts High Molecular Weight Mannich Bases Organylimidazolinyl Carbamates 2,6-Disubstituted-9-Oxabicyclononanes Carburetor Detergents Carbamates Monosubstituted Ureas Long Chain Alkylamino Alkyl-Substituted Ureas Polyamine, Phenol, Formaldehyde and Acid Reaction Product Diamine-Ethoxylated Polyphosphoric Acid Reaction Products Guanidine Petroleum S.ulfonate Polybutene-Substituted Nitrilotrisethylamine Substituted Succinamic Acids and Polyolefins Polyisobutylene-Substituted Polyamines Di(Hydrocarbon)Substituted Alkylene Polyamines Trimer Acid Polyesters Nonionic Surfactant as Demulsificr Anti-Icing Additives Hexylene Glycol Polyhydroxy Alcohol and Fatty Amides Polyhydroxy Alcohols and N-(Phenylstearyl)-l,3-Propylenediamine Fatty Imidazolines, Amides and Organic Silicon Compounds Benzole Acid with Common Deicers Polyethoxylated Propylenediamines E-4 ------- Table E-2 (continued) PBSA-Based Detergents Mixtures with Amine Salts of Sulfonic Acids and Polyethers Mixtures with Glycols and Glycol Ethers Adipic Aeid-N-(Hydroxyethyl)-Ethylene Diamine Reaction Products Polyhydric Alcohol Reaction Products Polyamine-Polyhydric Alcohols Reaction Products Sulfinyl-Containing Hydroxyl Compound Reaction Products Other Ashless Detergents Sulfonyl-Substituted Terpolymers Alkane Nitroamines Alkane Hydroxyamiries Oil-Soluble Azo Compounds Cyclohexanone Phenylhydrazone Oxidative Treatment Ash-Forming Detergents Overbased Sulfonate and Polyamine-Carboxylic Acids Polybutene Succinic Anhydride Treated Overbased Complexes Succinic Ester-Metal Salts Basic Magnesium Salts of Oil-Soluble Acids Coordinated Complexes of Nitrogenous Compounds Glycerol Ester FLOW IMPROVERS AND POUR DEPRESSANTS Ethylene-Based Polymers Vinyl Ester Copolymers Vinyl Acetate Copolymer and Fatty Acrylate Homopolymer Vinyl Ester Copolymer and Ethylene-Alpha-Olefin Copolymer Alkyl Fumarate Copolymers Alpha-Monoolefin Copolymers Ethylene-Propylene-1,4-Hexadiene Terpolymers Oxidized Ethylene-Propylene-Dicyclopentadiene Terpolymers Aryl-Substituted Polyolefins Other Polymeric Additives Hydrogenated Styrene-Butadiene Terminated with Polar Groups Polybutadienes Esters of Styrene-Malei.c Anhydride Copolymers Alkyl Itaconate-Maleic Anhydride Copolymers Vinyl Acetate-Alkyl Fumarate Copolymers Mixed Thiolacrylic Esters-Aminomethacrylate Terpolymers n-Paraffin-Free Saturated Hydrocarbons E-5 ------- Table E-2 (continued) Other Additives Polysaccharides N,N-DialkyIricinoleamides Fatty Amides and Salts Carboxylic Acid Esters of Polyhydric Alcohols Fatty Esters of Alpha-Methylglucoside Olefin-Alkyl Halide Reaction Products OXIDATION, CORROSION AND WEAR INHIBITORS Oxidation Inhibitors Aminoguanidine Derivatives Isoindoline Compounds 1-Azabicycloalkanes Three Component Amine and Amide Mixtures Tetracyanoethylene N-Substituted Alkoxyalkylamines Epichlorohydrin-Alkylamine Reaction Products Esters of (3,5-Dihydrocarbyl-4-Hydroxybenzyl)Thiodicarboxylic Acids Alkylhydroxyphenyl Thiolacyl Alkanoic Acid Esters Diphenyl Bis(3,5-Di-tert-Butyl-4-Hydroxyphenoxy)Silane Alkoxy-2,6-Di-tert-Butyl-p-Cresol and Dibutyltin Sulfide Alkylamine Salts of Phosphoric Acid Esters Bix(Hindered Phenol) Alkylene Diphosphonates Esters of PhosphorodithioateJ Phosphorodithioate Ester-Aldehyde Reaction Products Dihydrocarbylhydroxyphenyl Phosphonothionates and Phosphates Metal Alkyl Ester Tetrapropenylsuccinates Thermal Stabilizers Ethylene-Propylene-Diene Terpolymer—Maleic Acid Reaction Product Mannich Base, Dimer Acid and Metal Deactivator Substituted Carbamates and Aldehyde-Amine Condensation Products Cyclic Borates Corrosion and Rust Inhibitors Bis(l,3-Alkylamino)-2-Propanol and Phosphorylated Derivatives Nitro-Nitrito Alkanes, Alkylene Polyamines and .Sulfur Reaction Products Fatty Amides and Amines Tertiary Amine Oxide Concentrates 2-Hydroxy-5-Cetylbenzene-l,3-Dicarboxylic Acid Mixture of Carboxylic Acids and Pheno1-Aldehyde Resins Alkyl Sulfoxides Mercapto-Substituted Thiadiazoles E-6 ------- Table E-2 (continued) Antiwear Agents Diethers of Diethylene Glycol Bis(Hydroxyethyl)Alkane Phosphonates Lecithin and Substituted Imidazolines Trialkyl Phosphite-Alkenyl Succinic Anhydride Reaction Products Phosphorus Pentasulfide-Glycol Reaction Products Tetraoctyl Dimethylaminomethylene Diphosphonate Substituted Succinic Anhydride and Metal Sequestering Agent Tall Oil Fatty Acid SMOKE AND EMISSION CONTROL AND COMBUSTION AIDS Smoke Control Metal 2-Ethylhexanoates Barium Salts of Dialkyl Orthophosphoric Acids Barium Carbonate and Dimethyl Ether of Ethylene Glycol Barium Sulfonatocarbonate Barium Sulfide Treated with Acetic Acid Barium-Containing Dispersion Colloidal Dispersions Barium Alkaryl Sulfonates and Glycol-Ether Solvents Overbased Calcium Sulfonates and Nitropropane Cyclopentadienyl Manganese Tricarbonyl and Sulfinyl Amines Emission Control and Combustion Aids 4,4'-Benzylidenebis(2,6-Di-tert-Butylphenol) Polyalkoxylated Alkylphenol Additive Blend Boron Trifluoride Etherate-Amine Reaction Products Vanadium Salts of Phosphorus Compounds to Improve Rumble Tertiary Amines to Aid Air-Fuel Distribution Hydrocarbon Wax to Aid Air-Fuel Distribution Potassium Hexafluorozirconate and Organic Diamines Clay, Phosphate and Boron Oxides for Boiler Fuels Other Processes Molybdenum Naphthenate and Organomanganese Compounds Activated Manganese Oxide Surface Ignition Suppressors Aerosol Starting Agents for Diesels E-7 ------- Table E-2 (continued) ANTIKNOCK COMPOUNDS Tetraethyllead Triethylaluminum Reactions in Hexamethylphosphoramide Tetrahydrofuran Solvent and Catalyst Methyl Aluminum Sesquichloride and Sodium Fluoride Catalyst Coproduction of Alkali Metal Aluminum Tetraalkyls Ethylene dichloride Ethylene dibromide Tetramethyllead Sodium Amide Catalyst Diglyme, Methanol and Anthracene Catalyst Mixture Magnesium-Aluminum Alloy Catalyst Lithium-Aluminum and Mercury-Aluminum Catalyst Stable Concentrate Other Lead Compounds Hexaorganodiplumbanes Triorganolead Compounds Spirocyclic Lead Compounds Te traneopenty Head Organolead-Silicon Compounds Hexaaryldiliead Compounds Trialkylplumbylmagnesium Compounds and Organic Halides Metallic Lead Reactions Using Metallic Lithium Nonmetallic Additives 1,3-Diimino-2-Hydroxypropanes Mixed Nitrosoalkanes and Nitroso Aromatic Dimers Aminofulvenes ANTISTATS, BIOCIDES, DYES AND EMULSIFIED FUELS Antistatic Agents Phosphate Salts of Polyamides and Metal Naphthenates Monoamine-Fluorinated Polystyrene Reaction Products Cetyl Vinyl Ether-N-Vinylpyrrolidone Copolymers Olefin-Maleic Anhydride and Alkyl Vinyl Ether-Maleic Anhydride Copolymers Methyl Vinvyl Ether-Maleic Anhydride Copolymers Biocides Cyclic Imines N-Alky1-1,3-Propanediamine Naphthenyl Imidazolines E-8 ------- Table E-2 (concluded) Dyes Blue Dye Mixtures Azo Dye Compositions Emulsified Fuels Metallized Emulsion Carbon Fuel Emulsion Formulations Source: Ramsey, 1974, p. vii-x. E-9 ------- TECHNICAL REPORT DATA read iHStritctions on the wiv/w hcjorc fo 1. REPORT NO. EPA-450/3-78-031 4. TITLE AND SUBTITLE Assessment of Human Exposures to Atmospheric Benzene a. m CIIMI N i •:; A<:I:I :;:;ior*No. l> m roil i IJA 11 June 1978 6~ PhHFOHMINti OHCJANI/AI ION COHI 7. AUTHOR(S) Susan J. Mara Shonh S. Lee 8. PERFORMING ORGANIZATION REPORT NO Report No. 30R 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO. SRI International Center for Resource and Environmental Systems Studies 333 Ravenswood Ave. Menlo Park, California 94025 11. CONTRACT/GRANT NO. 68-01-4314 & 68-02-2835 12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED E.P.A. OAQPS & ORD RTP,NC 27711 Final 14. SPONSORING AGENCY CODE is. SUPPLEMENTARY NOTES This report supersedes all findings and conclusions in the first draft of this report which was entitled, "Human Exposures to Atmospheric Benzene." Project Officer: Richard Johnson 16. ABSTRACT This report is one of three reports which were prepared by E.P.A. to determine what regulatory action should be taken by E.P.A. to control sources of atmopsheric emissions of benzene. This report projects atmospheric concentrations of benzene and estimates the number of people exposed to these concentrations. These concentration estimates are developed on an emission source category basis are then integrated, using population flux estimates, thus, deriving total exposure estimates. The original draft of this report has received extensive review by the interested public and E.P.A.'s Science Advisory Board. All comments received on this first draft were reviewed and considered in preparation of this report. 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS benzene air pollution - populations exposures '•'•.•• atmospheric concentrations sources b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group CEMENT Unlimited 19. SECURITY CLASS (ThisReport! Unclassified 21. NO. OF PAGES 213 20. SECURITY CLASS (Thispage) Unclassified 22. PRICE EPA Form 2220-1 (9-73) E-10 ------- |