IMPACT
...of scientific evidence to support PROPOSED ozone limits
This year, the US Environmental Protection Agency (EPA) proposed strengthening national ground-level ozone limits. Ozone at ground level is one of the major air pollutants characteristic of large urban centers. High concentrations of ozone are caused by human activities, in particular, the combustion of gasoline- or diesel-fuel engines that run cars, trucks, and ships. The EPA’s action would replace the primary and secondary standards set in 2008, which were criticized for not offering enough protection to human health or vegetation by many stakeholders, including the EPA’s Clean Air Scientific Advisory Committee.
Professor Sverre Vedal, a pulmonary physician and epidemiologist in our department, serves on the committee’s Ozone Review Panel. He says scientific evidence clearly documents ozone’s impact on human lung function, countering charges from oil and gas industry representatives that the EPA’s move to strengthen the standard “lacks scientific justification.” Exposure to air pollutants has been linked to a number of serious health problems, including asthma and cardiovascular disease. According to the EPA, lowering the ozone limit from 75 parts per billion to 70 parts per billion will yield billions of dollars in health benefits by helping to reduce hospital and emergency visits, premature deaths, and missed work and school days.
In addition to changing the primary standard that targets public health, the 2010 proposal introduced a secondary standard designed to protect sensitive vegetation and ecosystems. Vedal noted that the secondary standard is a vital addition. Continued exposure to ground-level ozone reduces plant growth and increases susceptibility to disease, which can detrimentally affect agricultural productivity.
Compliance with the proposed standards will be a problem for many areas of the United States. In Washington, Enumclaw was cited last year by the state’s Department of Ecology for ozone levels that exceeded the current standard of 75 parts per billion. If the standard is set at 70 parts per billion, King County and other areas of the Puget Sound will likely fail to attain this level, and Spokane and Portland-Vancouver will be added to the nonattainment list if the standard is set at 60 parts per billion. Failing to comply with EPA standards triggers costly development of detailed plans to attain compliance in the future and could result in loss of federal funding.
In our department, research on air pollution and its impact on human health is ongoing and central to the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA-Air), the National Particle Components Toxicity (NPACT) Initiative, and the Disease Investigation through Specialized Clinically Oriented Ventures in Environmental Research (DISCOVER) Center, which among its projects includes experiments to study cardiovascular responses to diesel exposure. These efforts, in addition to faculty participation on key scientific committees, will continue to help inform policy and regulations that are based on sound science.
For further reading
Nadadur SS, Miller CA, Hopke PK, Gordon T, Vedal S, Vandenberg JJ, Costa DL. The complexities of air pollution regulation: The need for an integrated research and regulatory perspective. Toxicol Sci 2007;100(2): 318–27.
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