United States Environmental Protection Agency Environmental Sciences Research Laboratory Research Triangle Park NC 27711 Research and Development EPA-600/S3-83-002 Mar. 1983 v>EPA Project Summary Measurements of Hazardous Organic Chemicals in the Ambient Atmosphere H. B. Singh, L. J. Salas, R. Stiles, and H. Shigeishi Analytical methods were refined and applied to the ambient analysis of 44 organic chemicals, many of which are bacterial mutagens or suspected carcinogens. On-site field collection programs, based on single-site studies of 9 to 11 days duration each, were conducted in 10 U.S. cities. Field studies were performed with an instrumented mobile laboratory. A round-the-clock measurement schedule was followed at all sites. The field measurements allowed a determination of atmospheric concen- trations, variabilities, and mean diurnal behaviors of the chemicals. The data were analyzed relative to theoretically estimated removal rates. Typical diurnal profiles show highest concentrations of the primary pollutants during nighttime or early morning hours, with minimum concentrations in the afternoon hours. Chemistry plays only a nominal role in defining this diurnal behavior in most cases. Except for aromatic hydrocar- bons and aldehydes, average concentra- tions of the measured species were in the 0- to 5-ppb range. The average concentration range observed for aro- matics and aldehydes was 0- to 20-ppb. This Project Summary was developed by the Environmental Sciences Re- search Laboratory, Research Triangle Park. NC, to announce key findings of the research project that is fully docu- mented in a separate report of the same title (see Project Report ordering information at back). Introduction During the last 3 decades, an increas- ing number of synthetic organic chemicals have been released in large amounts into the ambient environment. Urban atmospheres contain a complex mixture of chemicals, many of which are toxic at concentrations significantly higher than those encountered in typical ambient atmospheres. The 3-year study was initiated to examine the range of concentrations of a variety of potentially hazardous gaseous organic chemicals* at selected urban locations under varying meteorological and source-strength conditions. The research effort studied 44 organic chemicals, of which 29 are bacterial mutagens and at least 12 are suspected carcinogens. The chemical categories targeted for field measurements included chlorofluoromethanes, nonfluorinated halomethanes, haloethanes, chloroethyl- enes, chloroaromatics, aromatic hydrocarbons, and oxygenated species. To achieve the study's general objective, procedures were developed for sampling and analysis of selected organic chemi- cals at expected ambient concentrations. The chemicals were measured and analyzed on-site in ambient air using a suitably outfitted mobile environmental laboratory. These field measurements were used to develop a reliable data base that could be used to better understand the concen- trations and diurnal behavior of the chemicals. Finally, information was obtained from the literature on sources, fates, and effects of these potentially hazardous chemicals. The overall *The term "hazardous chemicals" is not intended to imply that a proven human health hazard exists In most cases, toxicity studies are incomplete or incon- clusive and involve extrapolation of animal data to humans. ------- program of analytical methods refinement, field measurements, data collection, and data analysis is expected to provide information that will permit a better assessment of the atmospheric abundance and chemistry of this poten- tially harmful group of chemicals. Procedure All field work was conducted using a suitably instrumented mobile environ- mental laboratory. The ambient air sampling manifold was stainless steel and had a variable inlet height. In all cases, the sampling manifold was adjusted to be higher than nearby struc- tures; a typical manifold inlet height was 5 m above ground. A special stainless- steel metal bellows compression pump (Model MB 158) was used for pumping and pressuring air samples. For the anal- ysis of aldehydes, surface air was sampled in an all-glass apparatus. Various types of chromatography were used to analyze different chemicals. For all the monitored halogenated species and organic nitrogen compounds, electron-capture detector gas chromatography was the primary means of analysis. The aromatic hydrocarbons were measured using flame-ionization detector gas chromatography. Formaldehyde was measured by the spectrographic chemical analysis technique using the chromotropic acid procedure. In the third year of this research, formaldehyde and acetalde- hyde were also measured by analyzing the 2,4 dinitrophenylhydrazine deriva- tives, formed by reaction of 2,4 dinitro- phenylhydrazine with aldehydes, with high-performance liquid chromatograph- ic methods. After the measurement methodology was developed, field studies were conducted at selected urban sites in 10 cities in the continental United States. In consultation with the EPA Project Officer, the researchers chose the following cities: Los Angeles, CA, Phoenix, AZ, Oakland, CA, Houston, TX, St, Louis, MO, Denver, CO, Riverside, CA, Staten Island, NY, Pittsburgh, PA, and Chicago, IL Specific sites were chosen to represent open urban areas, and large point sources or topographical features that could affect the representativeness of the measurements were avoided. Every attempt was made to select sites that were indicative of general pollution levels prevalent in the area. Practical constraints such as power and shelter availability also influenced site selection. Only one site within each of the selected cities was monitored; therefore, while the collected data may be typical of the general ambient environment, they are truly representative only of the specific site monitored. Site locations and periods of field measurements are shown in Table 1. Each field study continued for approximately two weeks, and actual field data were collected from 9 to 11 days on a 24-hour basis. The preliminary literature search clearly indicated that limited data on hazardous organic chemicals are available and virtually all data have been collected during daytime hours. Based on past experience, the researchers believed that significant night and daytime differences in the abundance of organic chemicals were likely. Thus, a 24-hour-per-day, 7-days- a-week measurement schedule was chosen because it offered the most efficient means to collect the maximum amount of data to characterize the burden of toxic organic chemicals in the ambient air. In addition, night abundances of trace chemicals were likely to provide important information about the sources and sinks of measured species. Results The field measurements allowed determination of the atmospheric concentrations, variabilities, and mean diurnal behaviors of the chemicals. Although these studies were short-term, the 24-hour operation allowed for extensive data collection. The degree of temporal and spatial variability in the atmospheric abundance of toxic chemicals is clear from, the data pre- sented. Typical concentrations of most measured chemicals were in the sub- part-per-billion range, with the exception of aromatic hydrocarbons and formalde- hyde (where average concentrations in Table 1. Field Sites and Measurement Schedule Field Site No. Data City Name 1 2 3 4 5 Los Angeles, CA Phoenix, AZ Oakland, CA Houston, TX St. Louis. MO Latitude (°N) 34°04' 33°28' 37045' 29°47' 38°46' Longitude (°W) 1 18°09' 112°06' 122°11' 95° 15' 90° 17' Experiment Period 9 Apr 79 23 Apr 79 28 Jun 79 14 May 80 29 May 80 -21 Apr 79 - 6 May 79 - 10 Jul 79 - 25 May 80 - 9 Jun 80 Days of Actual Data Collection Site Address 10 11 9 10 10 Los Angeles State University 1 9th and A dam St. at state capitol Hegenberger and 14th St. Mae St. and 1- 10 Frontage Road 3400 Pershall Rd. (Florissant 6 Denver, CO 7 Riverside, CA 8 Staten Island, NY 9 Pittsburgh, PA 10 Chicago. IL 39045' 33°59' 40°35' 40°26' 41°45' 104°59' 15 Jun 80 - 28 Jun 80 11 117°18' 1 Jul 80 - 13 Jul 80 11 74°12' 26Mar81- 5 Apr 81 9 79°56' 7 Apr 81 - 17 Apr 81 9 87°42' 20 Apr 81- 2 May 81 9 Valley College) Marion St. - and E. 51st. Big Spring Rd. and Perimeter Road (U. C. Riverside campus) WildAve. and Victory Blvd. (Consolidated Edison Power Plant) Carnegie Mellon Institute (campui 79th St. and Lawndale ------- the 5 to 20 ppb range were frequently encountered). For most predominantly man-made chemicals, average concentra- tions in urban atmospheres were one to two orders of magnitude higher than in clean remote atmospheres. Tables 2, 3, and 4 summarize the ambient data collected at the 10 sites. Arithmetic means of the observed con- centrations (i.e., volumetric mixing ratios) and the associated one-sigma standard deviations in units of parts per trillion (ppt = 10~12 v/v) and in nanograms per cubic meter are tabulated. Minimum and maxi- mum concentration levels also are provided. The complete report also shows mean diurnal profiles for numerous species. Conclusions and Recommendations The research effort included analytical methods refinement, field-data collection, data processing, and data interpretation for a group of organic chemicals. The collected data reveal that typical concentrations of most measured chemicals were in the ppt range, and for most predominately man-made chemicals, average concentrations in urban atmospheres were one to two orders of magnitude higher than in clean remote atmospheres. There existed distinct mean diurnal variations in the concentrations of these atmospheric chemicals. For most chemicals, these variations were determined by source strength and prevailing meteorology, and chemistry played a nominal role. For several primary pollutants, afternoon mixing led to sufficient dilution to cause afternoon minima in concentrations; however, secondary photochemical pollutants (e.g., peroxyacetylnitrate and peroxypro- pionnylnitrate) showed clear afternoon maxima. Thus, for many of the hazardous chemicals, the highest concentrations in the ambient air were encountered during the nighttime or the early morning. Most of the measured chemicals have nearly exclusive man-made origin, and the significant elevation in concentration above background in urban areas, indicated that large sources associated with man-made activities exist in the area. The total concentrations of potential mutagens and carcinogens in urban ambient air may be much higher than those measured in this study because of the presence of nongaseous species (e.g., polynuclear aromatic hydrocarbons) and other gaseous species for which either toxicity studies are inconclusive or measurement methods are inadequate (e.g., oxygenated chemicals). Most synthetic chemicals in this study came into major use after 1950, and since that time their production and release have continued to grow exponentially, with a doubling time of about 6 years. This study indicates that typical urban atmospheres contain chemicals that are known to be toxic at much higher concen- trations. However, the task of characterizing the atmosphere, as exemplified by this study, is incomplete. Much more atmospheric and toxicity data are required to determine the risks asso- ciated with long-term exposures to low levels of toxic species. ------- Table 2. Atmospheric Concentrations of Measured Chemicals (Site 1 -3) Chemical Group and Species Los Angeles-Site 1 Phoenix-Site 2 Oakland-Site 3 (9-21 April 19791 (23 April - 6 May 19791 (28 June - 10 July 19791 PPt ng/m3 ppt ng/m3 ppt ng/m3 Mean' S.D ** Max Mm Mean SD. Mean SO. Max Mm Mean SO. Mean S.D Max Mm Mean S.D. Chlorofluorocarbons Trichlorofluoromethane (Fit) 473 197 1070 221 2653 1105 249 138 722 110 1396 774 239 151 1477 108 134O 847 lyrirf iiui uiiuvt VIIIGII tone \i if./ Trichlorotrifluoroethane (F1 13) Dichlorotetrafluoroethane fF1 14) Halomethanes Methyl chloride Methyl bromide Methyl iodide Methylene chloride Chloroform Carbon tetrach/onde Haloethanes and halopropanes Ethyl chloride 1, 1 Dichloroethane 1.2 Dichloroethane 1,2 Dibromoethane 1.1,1 Trichloroethane 1, 1,2 Trichloroethane 1, 1, 1,2 Tetrachloroethane 1. 1.2,2 Tetrachloroethane 1 ,2 Dichloropropane Chloroalkenes Viny/idene chloride (cis) 1,2 Dichtoroethylene Trichloroethy/ene Tetrach/oroethy/ene Ally I chloride Hexachloro-1 ,3 butadiene Chloroaromatics Monochlorobenzene rt»^» . i o-Dichlorobenzene m -Dichlorobenzene p-Dichlorobenzene 1,2,4 Tnchlorobenzene Aromatic hydrocarbons Benzene Toluene Ethyl benzene m/p-Xylene o-Xylene 4-Ethyl toluene 1.2.4 Trimethyl benzene 1,3,5 Trimethyl benzene Oxygenated species Formaldehyde Acetaldehyde Phosgene Peroxyacetylmtrate (Pan) Peroxypropionylnitrate IPPN) - \ 305 3001 244 3751 88 215 519 33 1028 9 4 17 5 399 1480 3 -200 13 8 7 6040 11720 2250 4610 1930 1510 1880 380 - 4977 722 667 4160 1759 7761 174 894 2620 12029 40 224 107 995 233 1353 26 187 646 3144 6 45 2 12 11 96 3 10 302 1 702 446 2065 2 8 - -500 10 50 6 25 5 34 4580 27870 9070 53380 4470 27660 6140 4996O 1830 12740 1450 10150 2380 13290 680 5020 - - 83 16820 673 2740 49 2333 5102 1038 6188 3626 13 946 752 601 13014 9090 24 427 194 97 1351 673 173 2097 942 5 252 198 224 5602 3520 4 49 33 <1 27 14 4 117 75 1 20 12 36 2142 1621 174 10028 3022 1 32 21 <50 918 2 78 60 2 48 36 2 52 37 720 19229 14581 1140 44010 34059 100 9735 19340 530 19945 26565 90 8350 7918 100 7396 7102 170 9208 11657 <40 1861 3331 . 30 24580 22141 <30 3978 3708 151 2391 67 894 111 277 216 40 824 16 9 17 30 484 994 7 -200 23 9 3 4740 8630 2000 4200 1780 1510 1740 400 - 779 93 225 '1251 940 5685 47 190 989 5155 106 514 114 855 220 1450 38 204 597 2814 10 42 4 16 6 31 16 150 587 3070 716 3697 9 58 - -500 35 236 6 28 2 1O 6750 59890 9090 38730 2870 16640 4660 26970 1880 9190 1500 7370 1910 10090 370 1520 - 767 3720 77 330 12 1155 1231 4928 4 260 86 3102 27 539 131 1741 39 873 2 305 198 4490 <1 87 <1 62 <1 117 <1 119 12 2598 129 6735 1 75 <50 918 1 138 1 54 1 22 390 15091 1721 1938 182 3431 515 717 889 290 3253 54 27 41 63 3151 4851 96 210 36 15 21490 540 32407 34134 60 8653 210 18171 40 7701 2OO 7396 20 8522 <40 1959 - - - <30 3847 <30 512 12417 20162 8134 7347 9355 1812 - - 3788 424 49 1066 55 416 32 169 83 16 291 8 4 7 13 188 308 1 -100 4 7 3 1550 3110 600 151O 770 660 - 50 356 149 5 309 781 5000 24 108 315 2406 12 60 133 987 106 842 13 85 161 967 4 29 1 8 3 13 5 24 270 1558 292 1450 0 3 - -300 5 33 3 15 2 15 1220 4630 3180 16940 670 4580 1420 8260 730 4050 620 3400 - 5 57 422 1850 118 500 16 484 26 86 13 94 38 2 143 4 <1 3 5 14 53 1 <50 1 3 1 60 150 60 too 80 20 42 50 <30 375 451 2197 1610 213 93 1443 1093 155 58 1062 836 335 428 122 99 1586 877 44 22 27 7 48 21 51 20 1009 1449 2087 1978 11 0 459 24 30 42 18 22 15 4935 3884 11678 11941 2596 2899 6533 6144 3331 3158 3233 3037 - - 202 20 1758 2084 821 650 * Arithmetic mean. ** One standard deviation. t Dashes indicate that chemical was not measured and/or standard deviations could not be computed. ------- Table 3. Atmospheric Concentrations of Measured Chemicals (Site 4-7) Houston-Site 4 (14-25 May 1980) ppt ng/m3 Chemical Group and Species Mean* S.D.** Max Min Mean S.D. Mean St. Louis-Site 5 (29 May - 9 June 1980) ppt ng/m3 S.D. Max Min Mean S.D. Chlorofluorocarbons Trichlorofluoromethane (F1 1) Dichlorofluoromethane (F12) Trichlorotrifluoroethane (F1 13) Dichlorotetrafluoroethane (F1 14) Halomethanes Methyl chloride Methyl bromide Methyl iodide Methylene chloride Chloroform Carbon Tetrachloride Haloethanes and Halopropanes Ethyl chloride 1,1 Dichloroethane 1,2 Dichloroethane 1,2 Dibromoethane 1, 1, 1 Trichloroethane 1,1,2 Trichloroethane 1,1,1,2 Tetrachloroethane 1,1,2,2 Tetrachloroethane 1,2 Dichloropropane Chloroalkenes Vinylidene chloride (cis) 1,2 Dichloroethylene Trichloroethylene Tetrachloroethylene Ally! chloride Hexachloro-1 ,3 butadiene Chloroaromatics Monochlorobenzene a - Chlorotoluene o -Dichlorobenzene m-Dichlorobenzene p-Dichlorobenzene 1,2,4 Trichlorobenzene Aromatic hydrocarbons Benzene Toluene Ethyl benzene m/p Xylene o-Xylene 4-Ethyl toluene 1,2,4 Trimethyl benzene 1,3,5 Trimethyl benzene Oxygenated species Formaldehyde Acetaldehyde Phosgene Peroxyacetylnitrate (PAN) Peroxypropionylnitrate (PPN) 474 897 199 28 955 100 3.6 574 423 404 227 63 1512 59 353 32 12 11 81 25 71 144 401 <5 11 309 <5 7 7 - 2 5780 10330 1380 3840 1307 870 1150 460 - - <20 438 110 178 474 190 10 403 58 2.2 553 749 449 273 20 1863 72 263 24 15 9 37 36 59 195 598 -t 20 517 - 9 8 - 2 5880 10850 1400 4270 1460 1030 1470 800 - - - 835 140 1105 2817 1664 58 2284 278 11.2 3404 5112 2934 1248 126 7300 368 1499 129 80 77 253 136 429 980 3215 <5 154 2785 58 67 47 - 13 37700 65650 7280 23780 9790 7470 9260 5350 - - <20 4350 630 305 482 37 12 531 45 0.6 49 38 126 10 9 50 10 134 <5 2 2 22 <4 21 5 34 <5 1 9 <5 1 1 - / 840 1040 50 270 80 60 50 70 - - _ <10 <10 2658 4430 1522 195 1968 388 21 1991 2055 2539 598 255 6110 450 1923 174 82 75 374 99 281 773 2717 <16 117 1419 26 42 42 - 15 18402 38790 5971 16614 5655 4261 5633 2253 - - 81 2163 606 998 2341 1453 70 831 225 13 1919 3638 2822 719 81 7528 550 1433 131 103 62 171 143 234 1047 4052 - 213 2374 - 54 48 15 18720 40743 6057 18474 6317 5045 7200 3918 - - 4124 771 374 622 132 25 732 81 2.6 421 73 129 46 60 124 16 235 15 6 6 53 9 39 112 326 <5 3 240 <5 6 4 - 1 1410 1520 640 950 310 240 370 530 11300 - <20 277 64 105 182 171 6 138 25 1.6 583 30 6 29 14 101 4 136 6 3 2 12 5 8 154 955 - 2 243 . 11 8 - 1 1190 1250 460 703 300 180 370 490 4500 - . 203 93 905 1156 1791 37 1015 125 7.2 6402 191 148 182 105 607 26 896 45 18 12 88 34 66 1040 7604 <5 10 1167 25 95 55 - 4 5820 6450 2100 3230 1490 1240 2560 1360 18700 - <20 890 250 217 383 22 13 531 7 0.2 82 25 112 10 26 45 8 132 6 4 4 22 <4 25 8 67 <5 1 5 <5 1 1 - 1 110 103 50 110 60 80 60 80 8100 - . 40 <10 2097 3072 1010 174 1509 314 15 1461 355 811 121 242 501 122 1281 82 41 41 244 36 154 601 2209 <16 32 1102 26 36 24 - 7 4489 5708 2769 4110 1341 1176 1812 2596 13836 - 81 1368 353 589 899 1308 42 284 97 9 2023 146 38 76 57 408 31 741 33 21 14 55 20 32 827 6471 - 21 1116 - 66 48 - 7 3789 4694 1990 3042 1298 882 1812 2400 5510 - . 1003 512 * Arithmetic mean. ** One standard deviation. t Dashes indicate that chemical was not measured and/or standard deviations could not be computed. ------- Table 3. (Continued) Chemical Group and Species Chlorofluorocarbons Trichlorofluoromethane (Ft 1) Dichlorofluoromethane (F12) Trichlorotrifluoroethane IF113) Dichlorotetrafluoroethane (F114) Halomethanes Methyl chloride Methyl bromide Methyl iodide Methylene chloride Chloroform Carbon tetrachloride Haloethanes and halopropanes Ethyl chloride 1,1 Dichloroethane 1,2 Dichloroethane 1,2 Dibromoethane 1,1, 1 Trichloroethane 1,1,2 Trichloroethane 1. 1, 1,2 Tetrachloroethane 1,1,2,2 Tetrachloroethane 1,2 Dichloropropane Chloroalkenes Vinylidene chloride (cis) 1,2 Dichloroethylene Trichloroethylene Tetrachloroethylene Ally! chloride Hexachloro-1,3 butadiene Chloroaromatics Monochlorobenzene a-Chlorotoluene o -Dichlorobenzene m-Dichlorobenzene p-Dichlorobenzene 1,2,4 Trichlorobenzene Aromatic hydrocarbons Benzene Toluene Ethyl benzene m/p-Xylene o-Xylene 4 -Ethyl toluene 1,2,4 Trimethyl benzene 1,3,5 Trimethyl benzene Oxygenated species Formaldehyde Acetaldehyde Phosgene Peroxyacetylnitrate (PAN) Peroxypropionylnitrate (PPN) Mean 637 1005 221 34 763 124 1.8 967 185 174 41 65 241 31 713 27 10 10 48 31 76 198 394 <5 2 290 <5 26 8 - 6 4390 6240 2220 2860 1280 900 1410 340 12300 - <20 443 45 Denver- -Site 6 (15-28 June 1980) ppt S.D.** Max Min 255 565 235 9 132 51 1.0 926 206 19 24 31 297 15 553 10 12 3 14 49 61 313 158 - 1 217 _ 34 7 - 4 3940 5280 3130 3320 1210 760 2310 240 5900 - - 7246 47 1246 3178 1608 60 1157 227 4.8 4874 1636 274 125 142 2089 78 2699 56 89 17 99 224 605 2483 1130 <5 7 1114 111 227 36 - 35 23910 24600 18520 20850 6000 4380 15450 1290 28700 - <20 11647 318 289 471 28 17 519 23 0.6 108 19 116 10 11 54 10 171 7 5 3 20 <4 25 7 99 <5 0.4 33 <5 2 1 - 1 110 290 90 150 <10 70 130 30 6600 - . 12 <10 ng/m3 Mean S.D. 3572 4963 1690 237 1573 481 10 3355 899 1094 108 263 974 237 3885 147 69 69 221 123 301 1063 2670 <16 21 1332 26 156 48 - 44 13976 23432 9605 12374 5538 4408 6906 1665 15061 - 81 2188 248 1430 2790 1798 63 272 198 6 3213 1001 119 63 125 1200 114 3013 54 82 21 65 194 242 1680 1071 . 11 996 204 42 - 30 12544 19827 13542 14364 5235 3722 11314 1176 7224 . . 6154 259 Mean 671 1056 274 29 703 259 2.8 1949 703 175 87 66 357 22 747 41 9 12 57 9 60 118 484 <5 4 <5 JO 6 - 10 3950 5800 1330 2231 1100 820 740 230 19000 - -50 1196 193 Riverside—Site 7 (1-13 July 1980) PPt S.D. Max Min 318 401 262 9 179 167 1.2 1406 798 23 65 22 325 7 257 21 3 9 15 6 14 55 236 - 3 . . 8 4 - 7 1910 3670 820 1515 650 460 500 170 7600 - - 1249 197 1860 2804 2211 62 1593 1033 6.2 9426 4747 267 312 147 2505 47 1349 89 18 77 88 56 173 236 1626 <5 16 - 39 76 21 - 40 10980 20070 4000 7340 3140 2650 3120 1260 41000 - - 5760 900 201 667 26 13 437 43 0.6 478 109 151 16 8 63 10 205 <5 4 5 11 <4 33 15 173 <5 1 - <5 3 1 - 2 520 450 25O 260 80 70 100 70 10400 - - 120 <10 ng/m3 Mean S.D. 3763 5215 2096 202 1449 1004 16 6762 3415 1100 229 267 1442 168 4070 223 62 82 263 36 238 633 3279 <16 43 - 26 60 36 - 74 12576 21780 5754 9652 4759 4016 3624 1127 23265 - 202 5907 1063 1783 1980 2004 63 369 648 7 4878 3876 145 171 89 1313 53 1400 114 21 62 69 24 55 295 1599 - 32 - - 48 24 - 52 6081 13781 3548 6555 2812 2253 2449 833 9306 - - 6169 1086 * Arithmetic mean. ** One standard deviation. t Dashes indicate that chemical was not measured and/or standard deviations could not be computed. ------- Table 4. Atmospheric Concentrations of Measured Chemicals (Site 8-10) Staten Island--Site 8 Pittsburgh-Site 9 (26 March - 5 April 1981) (7-17 April 1981) Chemical Group and Species Chlorofluorocarbons Trichlorofluoromethane (F1 1) Dichlorofluoromethane (F12) Trichlorotrifluoroethane (F1 13) Dichlorotetrafluoroethane (F1 14) Halomethanes Methyl chloride Methyl bromide Methyl iodide Methylene chloride Chloroform Carbon tetrachloride Haloethanes and halopropanes Ethyl chloride 1.1 Dichloroethane 1,2 Dichloroethane 1,2 Dibromoethane 1, 1, 1 Trichloroethane 1,1,2 Trichloroethane 1, 1, 1,2 Tetrachloroethane 1,1,2,2 Tetrachloroethane 1,2 Dichloropropane Chloroalkenes Vinviidefje chloride (cis) 1,2 Dichloroethylene Trichloroethylene Tetrachloroethylene Allyl chloride Hexachloro-1 ,3 butadiene Chloroaromatics Monochlorobenzene a-Chlorotoluene o -Dichlorobenzene m-Dichlorobenzene p -DichlorobenzenG 1,2,4 Trichlorobenzene Aromatic hydrocarbons Benzene Toluene Ethyl benzene m/p Xylene o-Xylene 4-Ethyl toluene 1,2,4 Tnmethyl benzene 1,3,5 Trimethyl benzene Oxygenated species Formaldehyde Acetaldehyde Phosgene Peroxyacetylnitrate (PAN) Peroxypropionylnitrate (PPN) Mean'' 360 519 129 39 701 84 2 1605 146 309 110 13 256 20 468 7 -t 26 18 167 292 - 4204 8975 1742 4088 1288 411 831 210 14300 747 204 ppt S.D.""" Max 143 909 190 1028 78 359 33 204 186 1208 108 671 1 4 2947 18476 117 872 202 1200 64 312 5 37 520 4312 6 36 248 1427 2 11 - 15 79 6 41 199 1005 200 1034 4287 19034 1O638 67304 2472 17230 8352 54638 2194 16189 468 2778 917 4682 273 1621 9100 45900 718 3888 527 3110 Min 175 318 59 21 446 27 1 226 38 125 10 3 55 12 221 3 - 10 8 26 79 - 82 623 9 170 47 13 62 51 7000 - . 65 32 ng/m3 Mean S.D. 2019 802 2563 938 987 597 272 230 1445 383 326 419 12 6 5846 10224 709 568 1942 1270 290 168 53 20 1034 2101 153 46 2550 1351 38 11 120 69 71 24 896 1068 1978 1355 - 13384 13648 337O2 39947 7537 10695 17687 36135 5573 9492 2013 2292 4070 4451 1029 1337 17510 11143 - _ 3689 3546 1 124 2904 Mean 333 496 68 30 665 41 1 390 97 331 84 12 121 16 486 6 4 4 23 13 96 409 6 5003 3928 765 1551 573 3O9 1034 121 20600 14OO 266 45 ppt SD Max 45 486 178 976 27 162 5 43 105 852 6 62 1 3 244 1308 41 238 107 691 45 229 15 105 35 237 10 59 272 1595 2 11 1 5 <1 4 8 50 5 25 93 420 357 1657 7 19 9818 64619 7286 46313 1564 10465 2357 10783 828 3787 416 2881 3349 24772 128 797 5200 35100 600 2600 _ 121 648 8 65 Mm 279 306 42 22 450 27 0 152 31 131 42 3 66 6 158 3 4 3 4 4 13 80 <1 392 386 69 110 43 39 39 45 12900 200 65 32 ng/m3 Mean S.D. 1811 252 2450 879 520 207 209 35 1371 216 159 23 6 6 1353 847 471 199 2081 673 221 118 48 61 489 141 122 76 2648 1482 33 11 27 7 27 7 106 37 51 20 515 499 2771 2419 64 75 15928 31257 147 SO 2736O 3310 6767 6710 10198 2479 3582 1513 2038 5064 16403 593 627 25224 6367 2514 1978 1314 598 248 44 Mean 389 718 82 36 856 47 2 1666 81 260 66 11 195 26 476 7 6 3 29 99 £.£. 19 225 590 - 2561 4629 786 1619 688 483 776 214 12800 1900 374 46 Chicago-Site 10 (20 April - 2 May 1981) ppt S D. Max 82 608 240 1251 65 359 9 73 168 1311 17 96 2 8 6653 56700 26 130 52 540 44 296 4 26 340 2820 37 249 158 909 3 14 10 35 1 6 7 40 1 Q KR i y oo 6 33 282 7386 452 7787 - 7779 8777 3264 14751 1168 9521 1477 7127 567 2777 365 2014 657 3268 203 1188 33OO 17200 1400 3100 349 1555 28 130 Min 277 270 20 22 575 21 0 128 25 120 10 5 22 6 241 3 2 2 10 4 18 90 588 790 69 153 90 112 131 106 9100 300 65 16 ng/m3 Mean S.D. 2182 460 3546 1185 627 497 251 63 1 764 346 182 66 12 12 5780 23082 393 126 1634 327 174 116 44 16 788 1374 198 282 2594 861 38 16 41 69 21 7 134 32 ft 7 ~7f\ O / fO 75 24 1208 1514 3998 3063 _ 8153 5664 17382 12257 3401 5053 7005 6390 2977 2453 2366 1788 3801 3218 1048 994 15673 4041 3412 2514 1847 1724 253 154 * Arithmetic mean. " One standard deviation. \ Dashes indicate that chemical was not measured and/or standard deviations could not be computed. U. S. GOVERNMENT PRINTING OFFICE: 1983/659-095/1912 ------- H. B. Singh. L J. Salas. R. Stiles, and H. Shigeishi are with SRI International. Menlo Park. CA 94025. Larry Cupitt is the EPA Project Officer (see below). The complete report, entitled "Measurements of Hazardous Organic Chemicals in the Ambient A tmosphere," (Order No. PB83-156 935; Cost: $11.50. subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, V'A 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Environmental Sciences Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 * °2 10N CHICAUO IL 60604 ------- |