EPA strengthens nitrogen dioxide standard
The Environmental Protection Agency this week released a new air quality standard for nitrogen dioxide aimed at reducing peak short-term exposure to the gas.
NO2 is formed by emissions from vehicles, power plants and other industrial facilities and contributes to particle pollution. Exposure to the gas has been linked to respiratory illness and infection -- particularly among at-risk populations such as children, the elderly and asthmatics.
The new one-hour standard level has been set at 100 parts per billion, and the agency is working with states to set up at least 40 new monitors in urban areas, EPA said. Cities with at least 500,000 residents will be required to place monitors near roadways, and communitywide monitoring will continue in cities with more than 1 million residents.
New monitors must begin operating no later than January 2013.