WASHINGTON The Environmental Protection Agency offered tighter standards for ozone pollution for the first time since 1997 but critics said on Thursday the proposal is more lax than what the EPA's own experts recommended.
The environment agency proposed the new rules for ground-level ozone -- damaging pollution also known as smog that is spawned by motor vehicle exhaust, power plants, gasoline vapors and chemical solvents -- late on Wednesday, suggesting an acceptable ozone range of 70 to 75 parts per billion over any eight-hour period.
That is lower than the current eight-hour standard of 80 parts per billion but higher than the 60 to 70 parts per billion unanimously recommended by the EPA's Clean Air Scientific Advisory Committee last October.
The EPA plan also leaves open the possibility of no change in the current standard. No action will be taken until March 2008, after four public hearings around the United States.
Unlike stratospheric ozone, which forms a protective layer high above Earth's surface, ground-level ozone can make it hard to breathe and can aggravate asthma and other respiratory conditions. It also can damage vegetation, trees and crops, making disease and reduced crop yields more likely.
People most vulnerable to lung problems from ozone pollution include children and teens, the elderly, those with asthma and other lung diseases and those who work or exercise outdoors.
"Advances in science are leading to cleaner skies and healthier lives," EPA Administrator Stephen Johnson said in a statement. "America's science is progressing and our air quality is improving. By strengthening the ozone standard, EPA is keeping our clean air momentum moving into the future."
The American Lung Association applauded the proposal as a "step toward cleaner air" but said, "The agency's plan falls short of the goal recommended by its own scientific experts...
"Unfortunately, the tightest new standard proposed by the EPA barely touches the more protective levels recommended by these same independent scientists," the lung association said in a statement.
The new proposed ozone standard would fail to protect U.S. residents from air pollution as required under the Clean Air Act, according to the lung association.
However, the National Petrochemical and Refiners Association said in a statement that no change is needed in the current standard "because it is working as intended and air quality is improving."
The association also said U.S. states have not yet fully implemented the present standard and urged the EPA to help in this process before proposing a new one.
Edison Electric Institute, which represents 70 percent of U.S. electric power companies, sounded a similar note, saying in a statement, "The (EPA) agency needs to make sure that any additional requirements imposed on states and local communities ... will produce real public health benefits."
But Dr. David Ingbar of the American Thoracic Society called the proposed standards "unhealthy for America's kids, unhealthy for America's seniors and unhealthy for America.
"There will be an extensive debate between now and March 2008 when EPA takes final action," Vickie Patton of the group Environmental Defense said by telephone.
The EPA's proposal was made under a court-supervised settlement with the American Lung Association and the environmental groups Environmental Defense, the Natural Resources Defense Council and the Sierra Club.