A Pittsburgh-area industrial zone is no longer a 'nonattainment' area for fine particulate matter

US environmental regulators have approved Pennsylvania's request to declare the Liberty-Clairton area in Pittsburgh as meeting federal air quality standards for fine particulate matter. This means the area no longer faces the strictest federal requirements for reducing air pollution.

For years, the Liberty-Clairton area has been one of the most polluted places in the US, largely due to heavy industry. This redesignation means the area is now considered to be in compliance with federal air quality rules, even though local residents still report significant air quality issues. It shifts the regulatory burden from mandatory pollution reduction to a maintenance plan, which can be less stringent.