Tuesday, November 17, 2009
EPA proposes new sulfur dioxide air standards
The US EPA today proposed new standards to limit short-term public exposure to the dangerous pollutant sulfur dioxide. See at http://www.epa.gov/air/sulfurdioxide/actions.html#nov09
The EPA standards could put more pressure on existing coal-fired power plants to clean up. The standards will underscore the urgency for the EPA to come up with an effective replacement for the Clean Air Interstate rule, which was set aside by the courts. (They would also provide a strong argument for the legislative effort by Senator Carper of Delaware to reduce power plant emissions.)
Coal-fired power plants produce the great bulk of sulfur dioxide, though emissions also come from smokestack industries and diesel engines. See at http://www.epa.gov/air/emissions/so2.htm#so2nat
(You may recall the controversy over the EPA effort to clean up big ships. Sulfur dioxide pollution was at issue. Some key Democrats in Congress recently meddled on behalf of special-interest polluters. Those meddlers look even more craven and off kilter in light of these new EPA standards.)
Sulfur dioxide is one of the six widespread air pollutants for which EPA sets health-based national air standards. Current EPA air quality standards for sulfur dioxide were set in 1971 and have not been updated to reflect new studies. The current standards limit only annual exposure and 24-hour exposure. See table at http://epa.gov/air/criteria.html for the nitty gritty.
Recent studies show there is health damage caused by short-term exposure – the kind of exposure that can happen under the current standards. The biggest problem is breathing problems among people with asthma, especially kids. There have been studies showing increased hospitalization and emergency room visits.
So EPA is proposing a new standard that would limit one-hour exposure.
Clean Air Watch and the American Lung Association will be urging the agency to set a final standard at the low end of the range – a one-hour standard no higher than 50 parts per billion.