Environmental Law Blog

The U.S. Environmental Protection Agency strengthened its national ambient air quality standard for ground-level ozone, the primary component of smog. The new rule, which reduced the amount of allowable ground-level ozone from 0.080 parts per million to .075 parts per million took effect on March 12, 2008.

The Clean Air Scientific Advisory Committee, a panel of experts appointed by EPA to make recommendations for the new standard, recommended that EPA lower its standard to somewhere between .060 and .070 parts per million. In spite of the discrepancy between the Committee's recommendations and EPA's final rule, EPA estimates that the revised standards will yield health benefits valued between $2 billion and $17 billion.

According to the EPA, breathing air containing ozone can reduce lung function and increase respiratory symptoms. The increased stress on respiratory systems can aggravate asthma, some heart conditions, lung disease, and other respiratory conditions. Ozone exposure also has been associated with increased susceptibility to respiratory infections, medication used by asthmatics, doctor visits, emergency department visits and hospital admission for individuals with respiratory disease.

In addition to health effects, ozone exposure can cause damage to sensitive vegetation and trees due to reduced growth and productivity, increased susceptibility to disease and pests, and damaged foliage. Ozone exposure can also cause reduced or sub-standard crop yield.

EPA last reviewed the national ambient air quality standard for ground-level ozone in 1997. In light of the twelve-year gap between EPA's ozone studies, should EPA have adopted the stricter standard advocated by the Clean Air Scientific Advisory Committee? Should Missouri support the new standard?