THE ENVIRONMENTAL Protection Agency is tightening the national air quality standard for ground-level ozone from 0.08 parts per million to 0.075 ppm. This concentration is still less stringent than what many experts contend is required to protect public health and prevent premature deaths.
"America's air is cleaner today than it was a generation ago," EPA Administrator Stephen L. Johnson noted when announcing the new standard on March 12. "By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward."
Johnson said the agency based its decision on the most recent scientific evidence about the effects of ozone, the primary component of smog. The change means that the air in 345 U.S. counties will violate federal standards, four times the current number of violators.
The American Chemistry Council, which represents 134 major chemical manufacturers, believes the 0.08-ppm limit sufficiently protects public health and is based on sound scientific information.
"The available science is largely unchanged since the 1997 standard was issued and demonstrates that there is no clear and substantial basis for making the standard stricter at this time," ACC said in a statement. Lowering the ozone standard "unnecessarily will impose significant new burdens on states and others even as they continue to try and comply with the 1997 standard."
In contrast, the American Lung Association has called for a much stricter standard, as have more than a dozen other public health and medical societies. In 2006, EPA's Clean Air Scientific Advisory Committee said a standard of between 0.060 and 0.070 ppm is needed to provide an adequate margin of protection for millions of people susceptible to respiratory illnesses.
Business groups waged an intense lobbying campaign to preserve the old standard. In meetings with EPA and White House officials, they argued that the estimated $8.5 billion annual cost of meeting a lower limit could hurt the economy.