NCPA - National Center for Policy Analysis

Air Quality Before The EPA

December 8, 1995

The federal Clean Air Act is pointed to as an environmental success story, since air quality in the United States has improved over the last 25 years. However, scientific data available at the time showed that air quality was already improving before the government acted.

Responding to a barrage of claims that air pollution was out of control, Congress passed the Clean Air Amendments of 1970, setting federal air quality standards, and established the Environmental Protection Agency (EPA) to enforce anti-pollution laws.

Yet observational data available from Continuous Air Monitoring Project stations set up in 1962 in six major cities -- Chicago, Cincinnati, Denver, St. Louis, Philadelphia and Washington, D.C. -- showed that in those urban areas:

  • Concentrations of settleable dust fell between 1925 and 1965.
  • Levels of sulfur dioxide fell between 1962 and 1968.
  • Total oxidants (ozone) fell between 1964 and 1968.
  • Carbon monoxide levels fell in four cities and rose in two cities between 1963 and 1968.

Also, data from the National Air Sampling Network, set up earlier, showed that:

  • Between 1957 and 1966, concentrations of airborne particulates fell in 58 urban areas and were almost unchanged in 20 nonurban areas.
  • Between 1962 and 1968, sulfur dioxide levels at 22 urban sites fell.

Reporting the data, scientists from the National Air Pollution Control Administration (predecessor of the EPA) suggested that the data was insufficient and said the "potential to pollute" should be projected as "a function of the product of population and standard of living raised to some exponent."

In fact, the trend toward cleaner air was driven by technological change, as well as state and local pollution controls, increasing electrification, and a shift from manufacturing to service industries. Similar changes were occurring elsewhere. For example, the average winter smoke levels recorded in London had been falling since the 1920s.

Until nationwide air quality standards were set, the authority of local and state pollution control units was limited to the police power to control nuisances. The federal law substituted sweeping powers to enforce restrictions on all sources of air pollution.

Source: Hugh W. Ellsaesser, "The Misuse of Science in Environmental Management," Policy Study No. 70, December 8, 1995, Heartland Institute, 800 E. Northwest Highway, Suite 1080, Palatine, IL 60067, (708) 202-3060.


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