1999 Modeled Ambient Concentration Maps

Geographic Area   (Select One)
United States Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware District of Columbia Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Puerto Rico Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virgin Islands Virginia Washington West Virginia Wisconsin Wyoming EPA Region 1 (CT ME MA NH RI VT) EPA Region 2 (NJ NY PR VI) EPA Region 3 (DC DE MD PA VA WV) EPA Region 4 (AL FL GA KY MS NC SC TN) EPA Region 5 (IL IN MI MN OH WI) EPA Region 6 (AR LA NM OK TX) EPA Region 7 (IA KS MO NE) EPA Region 8 (CO MT ND SD UT WY) EPA Region 9 (AZ CA HI NV) EPA Region 10 (AK ID OR WA)

Air Pollutant   (Select One)
Acetaldehyde Acetonitrile Acrolein Acrylamide Acrylic acid Acrylonitrile Allyl chloride Aniline Antimony compounds Arsenic compounds (including arsine) Benzene Benzidine Benzotrichloride Benzyl chloride Beryllium compounds Bis(chloromethyl)ether Bis(2-ethylhexyl)phthalate 1,3-Butadiene Cadmium compounds Carbon tetrachloride Chlorine Chloroform Chloroprene Chromium VI Cobalt compounds Coke Oven Emissions Cyanide compounds 1,2-Dibromo-3-chloropropane p-Dichlorobenzene Dichloroethyl ether 1,3-Dichloropropene Diesel particulate matter Diethanolamine Dimethyl formamide p-Dimethylaminoazobenzene 2,4-Dinitrotoluene 1,4-Dioxane Epichlorohydrin Ethyl acrylate Ethyl carbamate Ethylene dibromide Ethylene dichloride Ethylene oxide Formaldehyde Glycol ethers Hexachlorobenzene Hexachloroethane Hexamethylene-1,6-diisocyanate n-Hexane Hydrazine Hydrochloric acid Hydrofluoric acid Lead compounds Maleic anhydride Manganese compounds Mercury compounds Methyl bromide Methyl chloride Methylene chloride Methylene diphenyl diisocyanate 4,4'-Methylene bis(2-chloroaniline) 4,4'-Methylenedianiline Naphthalene Nickel compounds Nitrosodimethylamine Perchloroethylene Phosphine Polychlorinated biphenyls (PCBs) Polycyclic organic matter (POM) POM, Group 1 - Unspeciated POM, Group 2 - No URE data POM, Group 3 - 5e-2<URE<5e-1 POM, Group 4 - 5e-3<URE<5e-2 POM, Group 5 - 5e-4<URE<5e-3 POM, Group 6 - 5e-5<URE<5e-4 POM, Group 7 - 5e-6<URE<5e-5 POM, Group 8 - Unspeciated 7-PAH Propylene dichloride Propylene oxide Quinoline 1,1,2,2-Tetrachloroethane 1,1,2-Trichloroethane Titanium tetrachloride Toluene 2,4-Toluene diamine 2,4-Toluene diisocyanate o-Toluidine Trichloroethylene Triethylamine Vinyl bromide Vinyl chloride Xylenes (isomers and mixture)

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These maps illustrate the modeled ambient concentration of air toxics by county in 1999. Map colors indicate ranges of median concentration values, and each county is colored according to its value relative to the rest of the U.S. Pollutant concentration is expressed in micrograms per cubic meter of air (µg/m³).

If most counties have the same pollutant concentration value (e.g., for coke oven emissions), most of the map is shaded white. For some pollutants (e.g., ethylene dibromide, ethylene dichloride, carbon tetrachloride, and PCBs), the range of concentration values is very small. Therefore, variation in color for these maps represent relatively small changes in concentration.