The proposed EPA standard is very close to levels that are found naturally in some regions of the country.
Over the past several decades the U.S. has achieved remarkable success in reducing air pollution. According to the Environmental Protection Agency, the country has reduced six common air pollutants by 72% since 1970. These reductions are credited with achieving meaningful public-health benefits, from improved respiratory health to increased life expectancy.
Yet with this success we now face a critical question: Will further decreases in air pollution to levels that approach those that occur naturally necessarily result in additional public-health benefits? This question gets to the heart of the EPA’s current evaluation of whether the existing National Ambient Air Quality Standard for ozone is sufficient to protect public health. Ozone is a colorless, odorless gas that is not directly emitted into air, but is formed when sunlight reacts with two other pollutants: volatile organic compounds and nitrogen oxides. These come from many natural sources (plants, forest fires) as well as human-made sources (cars, industrial facilities, power plants).
The Clean Air Scientific Advisory Committee, a panel of scientists and public-health experts charged by Congress with advising the EPA, met in March to discuss the agency’s evaluation of the link between ozone and respiratory illnesses such as asthma and other health issues. The hope is that, with robust public input, the EPA and the committee will arrive at conclusions that accurately reflect the current state of scientific research on ozone. The stakes are significant: The EPA itself estimates that more-stringent standards could cost businesses up to $90 billion annually.
Currently the EPA standard for ozone in the air is 75 parts per billion, the strictest level since the standard was established in 1971. In 2008 the EPA determined, and a federal court agreed, that this standard protects public health. But now the EPA says that 75 ppb is not protective enough and is recommending a change to between 60 ppb and 70 ppb. Meanwhile, the overwhelming body of scientific evidence indicates lowering the current ozone standard will not provide added health benefits beyond those achieved with the current standard.