"U.S. EPA's final air quality standard for nitrogen dioxide (NO2) entails new requirements for measuring peak exposures near roads, but it would monitor fewer roadside locations than the agency's original proposal. ...
EPA's initial proposal required urban areas with more than 350,000 people to install at least one monitor near a major road, which would have mandated about 167 roadside monitors in about 142 urban areas. But the final rule raises that threshold to 500,000 people, requiring about 126 new monitors along roads in 102 urban areas.
Environmental and public health advocates are concerned about EPA's decision to monitor pollution along fewer roads, while state and local air regulators are urging the agency to start off with an even smaller roadside network until questions about costs and implementation have been answered."
Robin Bravender reports for Greenwire January 28, 2010.