Air Quality in the US: getting better? worse? staying the same?
EPA
monitoring systems
emissions inventories: the accounting of the amount of pollutants in the atmosphere collected by many different state local and tribal air agency sources.
air quality monitoring
require certain large industrial facilities to install state-of-the-art air pollution regulators when they build new facilities.
contingency measures
A link to a table that shows improvement in air quality since 1980
Potentially getting worse
A link to the EPA website talking about enforcement
A link to opinion piece in the New York Times