Using computer models and the latest emissions and cost data, the EPA study quantified air quality related health and environmental effects and their economic costs, estimated pollutant emissions in 1990, 2000 and 2010, and evaluated the costs of compliance with the Act.

The study shows that by the year 2010, the amendments to the Clean Air Act will prevent 23,000 Americans from dying prematurely each year, and avert over 1,700,000 incidences of asthma attacks and aggravation of chronic asthma.

At least 22,000 respiratory related hospital admissions would be averted, as would 42,000 cardiovascular hospital admissions, and 4,800 emergency room visits for asthma, the study's figures show.

The Clean Air Act Amendments of 1990 built upon the progress made by the original Act of 1970, and its 1977 amendments. The 1990 amendments strengthened the Act’s requirements to clarify and tighten implementation goals, increase the stringency of some requirements, revamp the hazardous air pollutant regulatory program, refine and streamline permitting requirements and introduce new programs for controlling acid rain and ozone depletion.

The current report, the most comprehensive and extensive assessment of the 1990 Clean Air Act Amendments ever conducted, was the subject of extensive peer review. Independent panels of economists, scientists, and public health experts provided in depth assessment and advice throughout the study's design, implementation, and documentation.

By contrast, the detailed cost analysis conducted for this new study indicates that the costs of achieving these health and ecological benefits are likely to be only about $27 billion, less than one fourth the economic value of the benefits.

The report, released Tuesday, notes that beyond the quantified human health benefits, there are a wide range of additional human health and environmental benefits which scientists and economists cannot yet quantify and express in dollar terms. These include the control of cancer causing air toxics as well as benefits to crops and ecosystems of reducing pollutants such as ozone and particulate matter.

The study is the second in a series of EPA cost/benefit Reports to Congress examining the effects of the Clean Air Act on the U.S. economy, public health, and the environment. The first study, a retrospective assessment released in October 1997, found that the benefits of clean air programs from 1970 to 1990 greatly exceeded their costs.

The current report points out areas in which additional research is needed in order to understand the relationship between air quality regulations and economic costs and benefits.

Based on the report, the EPA plans to call for:

• Improved emissions inventories and inventory management systems
• A more comprehensive air quality monitoring network for hazardous air pollutants and fine particles
• Development of tools to assess the significance of wetland, aquatic and terrestrial ecosystem changes associated with air pollution
• Increased basic research on the health effects of air pollution
• Continued development of economic valuation methods, particularly those associated with premature death