The Environmental Protection Agency says it plans to propose tightening standards for ground-level ozone for the first time since 1997. But EPA's June 21 announcement drew criticism from industry groups, which complain that the current ozone benchmark hasn't yet been fully implemented, and from environmentalists, who contend the plan isn't tough enough.

Since the standard was last updated, more than 1,700 studies examining ozone's impact have been completed. "Based upon current science, I have concluded that the current standard is insufficient to protect public health," EPA Administrator Stephen L. Johnson says.

EPA proposes to change the current eight-hour ozone standard of 0.08 parts per million to a range of 0.070 to 0.075 ppm. Lydia Wegman, director of the health and environmental impacts division in EPA's Office of Air and Radiation, says that as many as 398 U.S. counties now would be out of compliance if the standard were 0.075, and 533 wouldn't meet a 0.070 standard, based on 2003-2005 data, the latest available.

EPA also is considering lowering the standard further, to 0.60 ppm, though it may keep it at the current level.

Industry groups criticized the proposal. "Because the current standard hasn't even been implemented yet...we don't see the logic in moving the goalposts in the middle of the game here," says Bryan Brendle, National Association of Manufacturers' director of energy and resources policy. Brendle says that air quality already has begun to improve under the current standard, noting that levels of the six major pollutants regulated by the Clean Air Act have dropped more than 54% since the law was enacted 30 years ago.

Nick Goldstein, the American Road & Transportation Builders Association's director of regulatory affairs and assistant general counsel, says that state and county transportation funding could be jeopardized if more regions are designated nonattainment areas. "Transportation plans have been made around [the current] standards," Goldstein says. "Counties need some sense of predictability."

John Kinsman, Edison Electric Institute's director of air-quality programs, predicts that to meet tighter standards, states will be forced to get emissions cuts "not just from large industrial facilities, like utilities and refineries, but from a wide range of smaller sources throughout the country, including factories, paper mills, gas stations, small businesses and cars and trucks."

Environmental groups say EPA's proposal is too weak. Alice McKeown, a Sierra Club analyst, says, "We are concerned that EPA's willingness to consider keeping the current standard will turn out to be an escape route that allows the EPA to hide its duties and do nothing at all to make the air safer."

EPA will hold hearings and take comments on the proposal over the next few months. A final standard is expected by March 2008.