California regulators on Thursday approved the nation's toughest smog standard, citing new evidence that air pollution may be more harmful than scientists once believed, especially to children.
The California Air Resources Board voted unanimously to tighten the state's limit for ground-level ozone, the key ingredient in smog, after state officials produced a voluminous review of recent research into the health effects of the odorless, colorless gas.
But unlike federal air standards, the new state ozone rules are considered largely symbolic because the state does not enforce the rules.
State officials estimated that the tougher state standard, if it were met, would result in 580 fewer premature deaths a year, 3,800 fewer hospitalizations due to respiratory problems, 600 fewer asthma-related hospital visits among children, and 3.3 million fewer school absences for children ages 5 to 17.
The 1,000-page report analyzed the state of scientific knowledge on the health effects of exposure to ozone.
Environmentalists praised California for passing the rules, which surpass the federal pollution limits set by the Environmental Protection Agency. They said they hoped the move would lead federal officials to bolster their regulations as well.
"The ARB and its staff scientists have said very clearly that the current federal standard is not adequate to protect children and asthma sufferers," said Sonya Lunder of the Environmental Working Group, who had authored a report this month that tried to assess the costs of smog in California and advocated stricter regulations.
The state standard would limit ozone in the air to an average of 0.070 parts per million over an eight-hour period. The current federal regulation is 0.085 parts per million. However, unlike the federal ozone standard, which can result in a loss of federal transportation funding for local counties if it is not met, the state requirement carries little legal weight. It essentially represents the state's view of what constitutes clean air.
Despite its lack of teeth, some industry groups and other critics took issue with the state's tighter ozone standard, arguing that it would prove costly for businesses while having only a minimal health benefit.
Joel Schwartz, a visiting fellow with the American Enterprise Institute, estimated that the standard would cost tens of billions a year to meet while reducing premature deaths by 0.06%, respiratory-related hospital admissions by 0.28% and asthma-related hospital visits by 0.48%.
Ground-level ozone is created in the air by a chemical reaction between two types of pollutants: nitrogen oxides and volatile organic compounds. Both pollutants are commonly emitted during the burning of fossil fuels.
Breathing air polluted with ozone can cause wheezing, coughing and inflammation of the lungs, and can trigger a variety of respiratory problems, including asthma. Over long periods of time, it can cause permanent lung damage, studies have found.
Fourteen of the country's 25 worst ozone-polluted counties are in California, the American Lung Assn. noted in its annual report released Thursday.