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Transportation Air Quality Selected Facts and Figures

Emissions Sources

What are Sources of Emissions?

Emissions that affect air quality come from many sources. EPA groups sources into 8 major categories. The table below provides more detail about which sources are included in each sector.

Type of source Emissions
icon: barn Agriculture Crops & Livestock Dust; Fertilizer Application; Livestock Waste
icon: wind Dust Construction Dust, Paved Road Dust, Unpaved Road Dust
icon: flames Fire Agricultural Field Burning, Prescribed Fires, Wildfires
icon: power plant Fuel Combustion Commercial/Institutional (Biomass, Coal, Natural Gas, Oil, Other); Electric Generation (Biomass, Coal, Natural Gas, Oil, Other); Industrial Boilers and Internal Combustion Engines (Biomass, Coal, Natural Gas, Oil, Other); Residential (Natural Gas, Oil, Wood, Other)
icon: factory Industrial Processes Cement Manufacturing, Chemical Manufacturing, Ferrous Metals, Mining, National Electric Code (NEC), Non-ferrous Metals, Oil & Gas Production, Petroleum Refineries, Pulp & Paper, Storage and Transfer
icon: sky scrapers Miscellaneous Bulk Gasoline Terminals; Commercial Cooking Gas Stations; Miscellaneous Non-Industrial NEC; Waste Disposal
icon: car Mobile Aircraft; Commercial Marine Vessels; Locomotives; Non-Road Equipment – Diesel; Non-Road Equipment – Gasoline; Non-Road Equipment – Other; On-Road Diesel Heavy Duty Vehicles; On-Road Diesel Light Duty Vehicles; On-Road Gasoline Heavy Duty Vehicles; On-Road Gasoline Light Duty Vehicles
icon: barrel Solvent Consumer & Commercial Solvent Use; Degreasing Dry Cleaning; Graphic Arts; Industrial Surface Coating & Solvent Use; Non-Industrial Surface Coating

Source: U.S. Environmental Protection Agency,

Updated: 5/3/2016
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