WASHINGTON -- The Environmental Protection Agency released a contentious and long-awaited new limit on ozone pollution Thursday, and it's not likely to mark the end of the argument.
The EPA's final rule for ground-level ozone pollution, better known as smog, sets the standard at 70 parts per billion, lowered from the current standard of 75. Environmental and public health groups had been anticipating this figure for some time, though it is at the high end of what they wanted.
Industry groups like the National Association of Manufacturers and the American Petroleum Institute had asked the EPA not to lower the limit at all.
Nitrogen oxide and other volatile organic compounds emitted from factories, power plants and automobiles can cause the formation of smog. Exposure to high levels of ozone pollution can trigger respiratory problems, particularly in children, the elderly and people with lung conditions.
The agency's draft rule, released last November, suggested a limit somewhere between 65 and 70 parts per billion, though the agency also accepted comments on whether to reduce the limit to as little as 60 parts per billion.
The EPA's Clean Air Scientific Advisory Committee recommended last year that the standard be lowered and suggested that a limit of 70 parts per billion would provide "little margin of safety for the protection of public health, particularly for sensitive subpopulations." Setting it at the lower end of that range "would certainly offer more public health protection," the committee wrote.
In a call with reporters on Thursday afternoon, EPA Administrator Gina McCarthy defended a 70-parts-per-billion standard as the toughest the agency could do based on the currently available science. That science showed clear negative health impacts at 72 parts per billion, she said, but was less certain at lower levels.
"In this case, the science to me seems pretty clear," McCarthy said. "While there are no bright lines, I am convinced that at 70 we are doing what [the Clean Air Scientific Advisory Committee] said."
The Clean Air Act requires review of the standards every five years, which McCarthy said allows regulators to respond to further scientific developments on safe exposure levels. "I did the best with what I had, and I'm sure the next administrator will as well," she said.
The smog rule has been a subject of contention for years.
Under the George W. Bush administration, the EPA set the limit at 75 parts per billion in March 2008. Environmental and public health groups, joined by 11 state attorneys general, sued the Bush administration, arguing that the limit was too high. In January 2010, the EPA proposed lowering the limit to 60 to 70 parts per billion, but after months of delaying a final rule, President Barack Obama announced that he'd directed the agency to withdraw the ozone proposal as part of his efforts to reduce "regulatory burdens and regulatory uncertainty." Environmental and public health groups sued again, and a federal judge directed the EPA to produce a final rule by Oct. 1, 2015.
Public health groups like the American Lung Association had called for the standard to be set at the lower end of the proposed range. Representatives of the Sierra Club, the Natural Resources Defense Council, the NAACP and the environmental law firm Earthjustice said in a conference call with reporters on Monday that a standard of 70 parts per billion would be unacceptable.
David Baron, managing attorney for Earthjustice, said that 70 is "way above the level that doctors say we need to protect people from death, from hospitalization, from asthma attacks, from other serious health impacts. Setting the standard at 70 parts per billion would be nothing short of a betrayal of the Clean Air Act's promise."
There is "a good likelihood," Baron said Monday, that the groups would sue the EPA again if the standard were set at 70.
The oil industry and manufacturers had argued against lowering the standard at all, claiming that compliance would be difficult and costly in many parts of the country. Some Democrats from Western states also expressed concern about lowering the limit.
Jay Timmons, president of the National Association of Manufacturers, called the new standard "overly burdensome, costly and misguided" in a statement on Thursday. While he noted that "the worst-case scenario [of an even-lower standard] was avoided," he said the 70-parts-per-billion standard would still "inflict pain on companies that build things in America -- and destroy job opportunities for American workers." NAM called for Congress to block the standard through legislation.
Also on Thursday, the American Public Health Association's executive director, Dr. Georges Benjamin, said that a 60-parts-per-billion standard would have been "the most protective of public health, based on the latest science," but that lowering the limit to 70 "is a significant step in the right direction." The American Lung Association offered similar concerns, arguing that 70 offers more protection than 75, but "simply does not reflect what the science shows is necessary to truly protect public health."
This post has been updated with comment from EPA Administrator Gina McCarthy, the president of NAM and public health groups.