"Congress passed the Clean Air Act of 1970 based on the belief that reducing air pollution levels saves lives and improves health. The Act mandated the Environmental Protection Agency (EPA) to base its regulatory policies on good science. In 1997, EPA promulgated standards for fine particulate matter that were the most stringent and expensive in the agency’s 35-year history. The standards were widely criticized, and even EPA’s own science advisory committee did not endorse them. Instead of preventing 20,000 deaths and saving $69 to $144 billion a year at a cost of $6.3 billion (for partial attainment), as claimed, the standards have cost at least $70 billion a year to implement, eliminated hundreds of thousands of jobs a year, and likely have cost lives (because of the huge cost) without providing any public health benefit."

"One reason for this failure of public policy lies with the epidemiological environmental studies used. Two large studies served as the scientific basis for the standards promulgated—the 1993 Harvard Six Cities Study and the 1995 American Cancer Society Study. These and other studies showed only a weak association between exposure and disease or death—an increased relative risk of 1.26 and 1.17 respectively—and yielded several discrepant results."