The U.S. Environmental Protection Agency (EPA) announced on January 7, 2010, that it is proposing to replace the March 2008 smog standard with the strictest health standards to date for smog. Also known as ground-level ozone, smog is linked to a number of serious health problems, ranging from aggravation of asthma to increased risk of premature death in people with heart or lung disease.
Ground-level ozone forms when emissions from industrial facilities, power plants, landfills, motor vehicles, and other sources, including solvents classified as volatile organic compounds (VOC)—used in some paints—react in the presence of sunlight.
In September 2009, Administrator Jackson announced that EPA would reconsider the existing ozone standards of 0.075 parts per million (ppm). The agency is now proposing to set the “primary” standard, which protects public health, at a level between 0.060 and 0.070 ppm measured over eight hours. Children are at the greatest risk from ozone because their lungs are still developing; they are most likely to be active outdoors; and they are more likely than adults to have asthma. Adults with asthma or other lung diseases, and older adults are also sensitive to ozone. Ozone can also harm healthy people who work and play outdoors.
EPA is also proposing to set a separate “secondary” standard to protect the environment, especially plants and trees. This seasonal standard is designed to protect plants and trees from damage occurring from repeated ozone exposure, which can reduce tree growth, damage leaves, and increase susceptibility to disease.
Before making its new proposal, EPA conducted a review of the science that guided the 2008 decision, including more than 1,700 scientific studies and public comments from the 2008 rulemaking process. EPA also reviewed the findings of the independent Clean Air Scientific Advisory Committee, which recommended standards in the ranges proposed.
EPA will take public comment for 60 days after the proposed rule is published in the Federal Register. The agency will hold three public hearings on the proposal: Feb. 2, 2010, in Arlington, VA, and in Houston, TX; and Feb. 4, 2010, in Sacramento, CA.
More information: http://www.epa.gov/groundlevelozone.