The US Environmental Protection Agency announced a new national air quality standard for short-term exposures to nitrogen dioxide. Both the American Lung Association and American Petroleum Institute responded critically.
The new 1-hr standard of 100 ppb is directed at short-term NO2 exposures occurring mainly near major highways, EPA said. It added that it is retaining the 53 ppb average annual NO2 standard.
EPA said it plans to establish new monitoring requirements in urban areas to measure NO2 levels around major roads and across communities. Cities with at least 500,000 residents will be required to place monitors near roadways. Larger cities and areas with major highways will have additional monitors. Community-wide monitoring will continue in cities with at least 1 million residents.
"Working with the states, EPA will site at least 40 monitors in locations to help protect communities that are susceptible and vulnerable to elevated levels of NO2," EPA said.
The agency expects to identify or designate areas not meeting the new standard based on existing community-wide monitors, by January 2012, and will require new monitors to begin operating by Jan. 1, 2013. It also plans to redesignate areas when 3 years of air-quality data are available from the new monitoring network.
ALA said it was pleased that EPA acted, but had "hoped for a...more-protective standard." It said, "[EPA's] decision allows areas to have NO2 concentrations that remain hazardous to the millions of people.... [Its] final decision, unlike [its] proposal of last summer, allows twice as many days when NO2 will spike to dangerous levels."
API issued a statement saying it was "deeply concerned" with the new standard, which it said was based on faulty science. "There is no significant evidence that the short-term NO2 standard established today by [EPA Administrator Lisa P. Jackson] is necessary to protect public health. EPA is over-regulating this air-quality standard for political, not health, reasons," it said.