Rationing health protection: a proposal to exempt nuisance dust from US Clean Air Act regulations.

The US House of Representative has passed a bill called the "Farm Dust Regulation Prevention Act" (Dust Act) that would exempt most types of particulate matter (PM) in rural areas from the air quality controls of the US Clean Air Act. The Dust Act would markedly change the country's air quality standards. An examination of the proposed provisions shows that they would exempt non-combustion PM pollutants from mining, smelting, petroleum production, and power generation from existing air quality standards. Persons downwind from pollutants generated in rural areas could be exposed to concentrations of carcinogenic heavy metals, asbestos, and benzene known to adversely affect their health and ecological resources. Existing federal air quality standards based on science would be replaced by a flexible standard that rations health protection.