Environmental Protection Agency proposes national air quality standards.
D000397:Air Pollution / Q000517:prevention & control*; D002248:Carbon Monoxide / Q000592:standards; D004782:Environmental Health; D006077:Government Agencies; D006838:Hydrocarbons / Q000592:standards; D007883:Legislation, Medical; D009584:Nitrogen / Q000592:standards; D010087:Oxides / Q000592:standards; D013454:Sulfoxides / Q000592:standards; D014481:United States
D006838:Hydrocarbons; D010087:Oxides; D013454:Sulfoxides; D002248:Carbon Monoxide; D009584:Nitrogen