Letters were sent to 21 states and the District of Columbia by U.S. Environmental Protection Agency Administrator Mike Leavitt informing them that 243 counties in their jurisdictions have not attained federal standards for fine particulate matter (PM) in advance of formal designations in November. In the meantime, states will have an opportunity to challenge the EPA's preliminary determinations.
Most states are east of the Mississippi River, except for Missouri, Montana and California, affecting roughly 99 million people. Twenty-eight states are in attainment and the EPA Administrator for Region V noted a significant number of midwestern states underestimated the number of counties to be in nonattainment.
The PM 2.5 fine particle standards were established in 1997, but legal challenges slowed their implementation. In 2001, the U.S. Supreme Court upheld the standards and in 2002 all remaining legal challenges were cleared, allowing EPA to put these standards into effect. Meanwhile, the PM-10 microns standard remains in effect. The implementation of the new standards is expected to prevent people from suffering from aggravated asthma and spare others from respiratory failure.
States and Indian tribes will have submitted implementation plans by February 2008 to achieve the new PM standards by 2010 and 2015. State also will need to impose other measures to achieve nonattainment through emission standards for new sources and control measures for industrial pollutants. In April, EPA warned 18 states that 145 counties would be in nonattainment.
