THURSDAY, Jan. 7, 2010 (HealthDay News) -- The U.S. Environmental Protection Agency on Thursday proposed stricter standards for smog, which has been linked to a variety of health problems, including aggravated asthma and premature death from heart and lung disease.
The new standards, if adopted by the agency after a 60-day period of public comment, would replace controversial smog limits adopted during the last year of the administration of President George W. Bush that ran counter to scientific recommendations.
"EPA is stepping up to protect Americans from one of the most persistent and widespread pollutants we face," EPA Administrator Lisa P. Jackson said in a news release issued Thursday morning. "Smog in the air we breathe poses a very serious health threat, especially to children and individuals suffering from asthma and lung disease. It dirties our air, clouds our cities, and drives up our health-care costs across the country. Using the best science to strengthen these standards is a long overdue action that will help millions of Americans breathe easier and live healthier."
According to the EPA, smog -- also called ground-level ozone -- can contribute to serious health problems, ranging from aggravation of asthma to increased risk of premature death in people with heart or lung disease. Smog can also harm healthy people who work and play outdoors.
Children are most vulnerable to health problems from ozone because their lungs are still developing, they're more likely to be active outdoors, and they're more likely than adults to have asthma. But adults with asthma or other lung diseases, and older adults are also sensitive to ozone's effect, the agency said.
Smog is created when emissions from factories, power plants, landfills and motor vehicles react in the sun. It is particularly prevalent in urban areas and regions with heavy motor vehicle use.
The EPA said in its news release that it is proposing to set the "primary" smog standard at a level between 0.060 and 0.070 parts per million (ppm) measured over eight hours.
The EPA said it's also proposing a separate "secondary" standard to protect the environment, especially plants and trees. This so-called seasonal standard is intended to shield plants and trees from damage from repeated ozone exposure, which can "reduce tree growth, damage leaves, and increase susceptibility to disease," the agency said.
Last September, Jackson said the EPA would reconsider the existing ozone standards, which had been set at 0.075 ppm in March 2008 by the Bush administration. As part of its review, the EPA said it re-examined the science that led to the 2008 decision, including more than 1,700 scientific studies. The agency said it also reviewed the findings of the independent Clean Air Scientific Advisory Committee, which recommended standards in the range proposed Thursday by Jackson.
Depending on the final standards adopted, the proposal would produce health benefits of between $13 billion and $100 billion. The proposal would "help reduce premature deaths, aggravated asthma, bronchitis cases, hospital and emergency room visits, and days when people miss work or school because of ozone-related symptoms," the EPA said.
The new limits would likely put hundreds more U.S. counties in violation of clean air standards, requiring them to find additional ways to reduce pollution or face government sanctions, most likely the loss of federal highway dollars, the Associated Press reported.
The proposed ozone range unveiled Thursday was what scientists had recommended during the Bush administration. But, former President Bush personally intervened and set the standard above what was advised after protests from electric utilities and other industries, the news service said.
The EPA said it would take public comment for 60 days after the proposed ozone rule is published in the Federal Register. The agency will also hold three public hearings on the proposal: Feb. 2 in Arlington, Va., and Houston, and Feb. 4 in Sacramento, Calif.
Responding to Thursday's announcement, Charles D. Connor, president and chief executive officer of the American Lung Association, said in a news release: "With today's announcement, EPA is following the overwhelming evidence that our nation needs a stronger ozone standard. EPA owes this protection to the millions who live where ozone smog sends children to the emergency room and shortens the lives of people with chronic lung disease. We urge the [EPA] to adopt the strongest, most protective standard when they make the final decision in August.
"Nearly two years ago, EPA selected a standard for ozone that was too weak -- allowing far more pollution than compelling research said was safe," Connor added. "The Lung Association and our colleagues immediately took legal action to require EPA to reconsider their decision. Today, EPA proposed the range that their advisors had long recommended."
For more on ozone, visit the U.S. Environmental Protection Agency.