2002 Almanac (page 456) Table C-18 San Joaquin Valley Air Basin: Annual Average Concentrations and Health Risks by Site Annual Average Concentration* Health Risk** COUNTY / SITE TAC 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 KERN Bakersfield-Chester Avenue Acetaldehyde 1.87 1.83 1.60 2.00 9 9 8 10 Benzene 2.68 2.22 1.54 1.47 248 205 143 136 "1,3-Butadiene" 0.39 0.31 0.24 0.33 146 115 90 123 Carbon Tetrachloride 0.13 0.13 0.10 33 33 27 Chromium (Hexavalent) 0.21 0.21 31 31 para-Dichlorobenzene 0.12 0.17 8 11 Formaldehyde 2.44 1.62 1.36 1.85 18 12 10 14 Methylene Chloride 0.92 0.65 0.52 0.99 3 2 2 3 Perchloroethylene 0.09 0.13 0.08 1.48 4 5 3 59 Diesel PM No Monitoring Data Available Total Health Risk 461 381 295 414 KERN Bakersfield-5558 California Avenue Acetaldehyde 0.49 1.59 1.22 1.27 1.69 1.19 2 8 6 6 8 6 Benzene 1.14 0.78 0.57 0.70 0.71 0.58 106 72 53 65 66 54 "1,3-Butadiene" 0.21 0.21 0.16 0.20 0.15 0.13 78 79 60 75 58 47 Carbon Tetrachloride 0.10 0.08 0.09 26 21 25 Chromium (Hexavalent) 0.26 0.13 0.10 0.10 0.10 0.10 39 19 15 15 16 16 para-Dichlorobenzene 0.11 0.11 0.12 0.11 7 7 8 7 Formaldehyde 1.92 3.48 3.12 2.99 3.67 2.79 14 26 23 22 27 21 Methylene Chloride 0.54 0.64 0.50 0.50 0.58 2 2 2 2 2 Perchloroethylene 0.09 0.12 0.04 0.07 4 5 2 3 Diesel PM No Monitoring Data Available Total Health Risk 278 239 169 183 177 181 FRESNO Fresno-1st Street Acetaldehyde 2.29 1.89 1.40 0.67 1.50 1.43 11 9 7 3 7 7 Benzene 2.42 1.34 1.35 1.44 1.24 0.79 1.00 0.83 0.80 0.73 224 124 125 133 115 73 92 76 74 68 "1,3-Butadiene" 0.46 0.26 0.34 0.36 0.30 0.23 0.23 0.27 0.21 0.20 173 99 129 134 113 88 87 100 80 73 Carbon Tetrachloride 0.12 0.11 0.10 0.08 0.10 32 28 26 21 25 Chromium (Hexavalent) 0.21 0.15 0.14 0.22 0.10 0.11 0.10 0.10 0.13 31 22 21 33 16 16 15 15 20 para-Dichlorobenzene 0.10 0.10 0.14 0.13 0.11 0.14 0.10 7 7 9 8 7 9 7 Formaldehyde 2.32 1.64 2.01 2.41 3.42 3.56 17 12 15 18 25 26 Methylene Chloride 0.62 0.54 0.69 0.59 0.58 0.50 0.52 0.50 2 2 2 2 2 2 2 2 Perchloroethylene 0.14 0.10 0.10 0.06 0.07 0.04 0.04 0.06 6 4 4 2 3 2 2 2 Diesel PM No Monitoring Data Available Total Health Risk 465 267 338 323 321 209 208 223 169 230 STANISLAUS Modesto-I Street (Courthouse) Acetaldehyde 1.51 1.37 1.75 1.44 0.51 1.17 1.25 7 7 8 7 2 6 6 Benzene "1,3-Butadiene" Carbon Tetrachloride Chromium (Hexavalent) 0.27 0.23 0.22 0.32 0.16 0.11 40 34 33 48 25 17 para-Dichlorobenzene Formaldehyde 1.43 1.32 1.82 1.86 2.16 2.58 2.43 11 10 13 14 16 19 18 Methylene Chloride Perchloroethylene Diesel PM No Monitoring Data Available Total Health Risk 18 57 55 54 66 50 41 STANISLAUS Modesto-14th Street Acetaldehyde 1.65 8 Benzene 2.25 1.86 1.20 1.23 1.14 1.20 0.70 0.77 0.85 0.61 208 172 111 114 105 111 65 71 78 56 "1,3-Butadiene" 0.38 0.35 0.22 0.35 0.29 0.30 0.24 0.21 0.26 0.16 142 133 84 131 110 112 89 78 98 61 Carbon Tetrachloride 0.13 0.13 0.11 0.09 0.07 0.11 34 35 30 25 20 30 Chromium (Hexavalent) 0.10 15 para-Dichlorobenzene 0.11 0.10 0.12 0.10 0.11 0.10 0.15 7 7 8 7 7 7 10 Formaldehyde 3.09 23 Methylene Chloride 0.65 0.61 0.55 0.65 0.62 0.58 0.50 0.59 0.51 2 2 2 2 2 2 2 2 2 Perchloroethylene 0.15 0.15 0.12 0.11 0.09 0.05 0.04 0.05 0.04 6 6 5 4 3 2 2 2 1 Diesel PM No Monitoring Data Available Total Health Risk 392 355 209 289 227 259 185 163 209 163 SAN JOAQUIN Stockton-Hazelton Street Acetaldehyde 1.47 1.75 1.07 1.31 1.10 0.90 0.90 1.00 1.07 0.64 7 9 5 6 5 4 4 5 5 3 Benzene 2.01 1.95 1.37 1.23 1.05 0.64 0.52 0.69 0.65 0.58 186 181 127 113 97 60 48 64 60 54 "1,3-Butadiene" 0.34 0.32 0.22 0.28 0.25 0.21 0.18 0.21 0.18 0.16 126 121 82 106 94 77 68 77 68 58 Carbon Tetrachloride 0.13 0.14 0.10 0.08 0.12 0.10 35 36 26 20 30 26 Chromium (Hexavalent) 0.22 0.25 0.25 0.14 0.10 0.12 33 37 37 21 15 18 para-Dichlorobenzene 0.10 0.10 0.10 0.11 0.10 0.11 0.11 7 7 7 7 7 7 7 Formaldehyde 1.81 1.88 1.24 1.38 1.56 2.35 2.24 2.33 2.68 1.61 13 14 9 10 12 17 16 17 20 12 Methylene Chloride 0.63 0.50 0.60 0.50 0.75 0.53 0.50 0.50 0.50 0.53 2 2 2 2 3 2 2 2 2 2 Perchloroethylene 0.13 0.11 0.12 0.07 0.06 0.07 0.09 0.03 0.11 5 5 5 3 2 3 4 1 4 Diesel PM No Monitoring Data Available Total Health Risk 374 375 270 53 285 229 211 149 196 170 184 BASIN SUMMARY Acetaldehyde 1.94 1.84 1.38 1.73 1.29 0.54 1.28 1.19 1.30 1.56 1.09 9 9 7 8 6 3 6 6 6 8 5 Benzene 2.45 2.11 1.36 1.32 1.33 1.16 0.73 0.71 0.76 0.69 0.63 227 196 126 122 123 107 68 66 71 64 58 "1,3-Butadiene" 0.41 0.36 0.24 0.34 0.32 0.26 0.22 0.20 0.23 0.18 0.16 154 135 89 127 121 99 83 73 88 67 59 Carbon Tetrachloride 0.13 0.13 0.11 0.10 0.08 0.11 0.10 34 34 29 26 20 30 25 Chromium (Hexavalent) 0.23 0.21 0.19 0.28 0.13 0.11 0.10 0.10 0.12 34 31 29 42 20 16 15 15 18 para-Dichlorobenzene 0.11 0.11 0.13 0.11 0.11 0.10 0.13 0.11 7 7 9 7 8 7 9 7 Formaldehyde 2.45 1.81 1.46 1.67 1.80 2.10 2.96 2.77 2.86 3.44 2.61 18 13 11 12 13 15 22 20 21 25 19 Methylene Chloride 0.76 0.59 0.55 0.76 0.59 0.61 0.54 0.53 0.52 0.50 0.53 3 2 2 3 2 2 2 2 2 2 2 Perchloroethylene 0.13 0.13 0.10 0.47 0.07 0.07 0.07 0.06 0.04 0.08 5 5 4 19 3 3 3 2 2 3 Diesel PM*** 2.6 1.7 1.3 780 510 390 Average Basin Health Risk 450 401 280 360 304 305 231 194 235 181 196 * Concentrations for Chromium (Hexavalent) are expressed as ng/m3 and concentrations for Diesel PM are expressed as ug/m3. Concentrations for all other TACs are expressed as parts per billion. ** Health Risk represents the number of excess cancer cases per million people based on a lifetime (70-year) exposure to the annual average concentration. Total Health Risk represents only those compounds listed in this table and only those with data for that year. There may be other significant compounds for which monitoring and/or health risk information are not available. "*** The Diesel PM concentrations are estimates based on receptor modeling. Because data are not available for all years, Diesel PM is not included in the Average Basin Health Risk number. "