Top Sources of Pollution in the United States (EPA Data)

According to the U.S. Environmental Protection Agency (EPA), the largest anthropogenic pollution sources by sector are:

1. Transportation — #1 Air Polluter

• ~29% of total U.S. GHG emissions (2022).
• Light-duty vehicles (cars/SUVs) = 58% of transport emissions.
• Medium/heavy trucks, aircraft, rail, ships.
• Pollutants: CO₂, NOₓ, VOCs, PM₂.₅, CO, benzene.

2. Electric Power — #2 (but Falling)

• ~25% of GHG. Coal (~60% of sector CO₂), natural gas (~40%).
• SO₂, NOₓ, mercury, PM, CO₂.
• Rapid decarbonization: coal ↓, gas/renewables ↑.

3. Industry — #3

• ~23% of GHG (direct emissions).
• Cement, steel, chemicals, refining, pulp/paper.
• Process emissions (chemical reactions) + combustion.
• Toxic releases (TRI): metals, solvents, PFAS.

4. Commercial & Residential Buildings

• ~13% direct GHG (heating, cooking, waste).
• ~30% total if electricity end-use allocated.
• Gas furnaces, oil boilers, HFC refrigerants.

5. Agriculture

• ~10% GHG (methane from enteric fermentation/manure, N₂O from soils).
• Water: #1 source of nutrient pollution (N/P runoff → dead zones).
• Ammonia, pesticides, sediment.

6. Waste Management

• Landfills: ~14% of U.S. methane (3rd largest source).
• Leachate → groundwater.
• Incineration: dioxins, heavy metals.

Regional Variation

• California: Transport + wildfires.
• Ohio Valley: Industry + coal power.
• Gulf Coast: Petrochemical + refineries.
• Corn Belt: Ag runoff.

EPA's Air Trends Report and National Emissions Inventory (NEI) provide granular, current data.