Benefits and Costs of the Clean Air Act, 1970 to 1990

Government report excerpt

By: United States Environmental Protection Agency

Date: October 15, 1997

Source: U.S. Environmental Protection Agency. "Benefits and Costs of the Clean Air Act, 1970 to 1990." 〈http://www.epa.gov/air/sect812/812exec2.pdf〉 (accessed January 17, 2006).

About the Organization: The U.S. Environmental Protection Agency (EPA), established in 1970, is generally responsible for protecting the U.S. environment and preserving its integrity for future generations. Its specific aims include controlling and reducing water and air pollution, noise pollution, and pollution by pesticides, radiation, and various toxic substances.

INTRODUCTION

Air pollution is a relatively new concept, first perceived as the impact of human activity in the industrial era upon the public health. The correlation between industrial emissions of air pollutants and the increase of cases of allergy, asthma, and other respiratory disorders in a given population was initially noticed by physicians and public health researchers known as epidemiologists. Epidemiology research had shown that air pollution had a major impact on the augmented incidence of respiratory diseases among infants, small children, and elderly citizens, the most affected groups among the general population. Stationary emissions (pollutants released in the atmosphere by power plants, factories, oil refineries, and steel mills) were identified as the main sources of air pollution in the first half of the twentieth century. Examples of such air pollutants are sulfur dioxide (SO₂), carbon monoxide (CO), carbon dioxide (CO₂), nitrogen oxides (NO_x), dioxins, furans, polycyclic aromatic hydrocarbons (PAHs), and suspended particulate matter. Particulate matter may be already present as solid particles, such as visible smoke from industrial smokestacks and motor vehicle exhaustion, or can be formed due to the chemical reaction of gaseous pollutants, such as nitrogen oxides and sulfur dioxide, in the atmosphere. In the first case, such emissions are known as "primary particulates," while those formed by gaseous pollutants are known as "secondary particles or particulates."

More recent studies have shown that dioxins, furans, and PAHs are carcinogenic compounds that induce DNA mutations, thus leading to cancer and fetus malformation. Well-known sources of atmospheric dioxins are timber mills, which apply chemical treatments to timber, and paper mills. PAHs and sulfur dioxides are released by oil refineries, motor vehicle emissions, paint factories, and the manufacturing of oil-derived chemical products and byproducts such as benzene and domestic and industrial solvents.

Respiratory allergies and correlated respiratory disorders are also associated with the increase of ozone gas (O₃) in the lower layer of atmosphere (known as the troposphere) due to emissions of organic compounds such as PAHs, dioxins, methane, nitrous oxides, and furans, among others. In the stratosphere, the ozone layer plays the crucial role of decreasing the incidence of ultraviolet radiation upon the Earth. However, the formation and build-up of ozone gas in the troposphere results in the man-made fog known as "smog," which besides being highly allergenic also contributes to the greenhouse effect. Therefore, the air pollution derived from human activity affects atmospheric ozone in two different ways: by abnormally increasing ozone concentrations in the troposphere and by destroying the stratospheric ozone layer. In the last case, a direct impact on public health is also reported, since a thinner stratospheric ozone layer permits higher amounts of ultraviolet radiation to reach the planet's surface, causing an increase in skin cancer and melanoma incidence among humans.

In 1955, several state and local administrations had already passed legislation to control air pollution and improve air quality when the U.S. Congress approved the first federal Air Pollution Control Act. The document recognized air pollution as a public health problem and provided research funds for the Public Health Service. However, it did not tackle air pollution control and prevention directly, recommending only that additional measures should be taken to improve air quality. This Act was amended in 1960 to provide research funds for another period of four years. The 1955 Act had its focus only on stationary sources of air pollution, not taking into consideration emissions by motor vehicle exhaust. It was only when the second amendment was approved by Congress in 1962 that funds were allocated for the research of the effects upon public health of motor vehicle exhaust emissions and its chemical compounds.

The first concrete Congressional effort to effectively control air pollution came in 1963 under the Clean Air Act, defined as "An Act to improve, strengthen, and accelerate programs for the prevention and abatement of air pollution." The 1963 Act recognized the impact of motor vehicle emissions as a deteriorating factor for air quality in urban areas and recommended the establishment of emission-control standards for both stationary sources and motor vehicles alike. The Act also allocated a $95 million fund for a three-year research effort by local, state, and federal air pollution control agencies to conduct studies and develop standardized control programs. The Clean Air Act also recommended the removal of sulfur from fuels derived from coal and oil, and the reduction of these emissions. This legislation was amended in 1965 to include standards for automobile emissions, and in 1966 to expand local air pollution control programs. A further amendment in 1967 divided the country into "Air Quality Control Regions" (AQCRs) in order to implement a program of ambient air monitoring. This 1967 amendment also adopted national standards for stationary emissions and established a schedule for State Implementation Plans (SIPs). It also recommended (and allocated federal grants) to the research and development of new control technologies to achieve the SIPs' objectives. The amendment of 1969 extended funds research on lowemission automobiles and fuels.

In 1970, the Clean Air Act of 1963 was completely revamped, yielding a new and more ambitious piece of legislation on air pollution abatement, known as the Clean Air Act of 1970. Its goals were defined as "An Act to amend the Clean Air Act to provide for a more effective program to improve the quality of the Nation's air." Standards for motor vehicle emissions and for hazardous stationary emission were set, and a $30 million fund was designated for research of the impact of noise pollution upon public health, especially in large urban centers. In order to protect public health, the Act established the National Ambient Air Quality Standards as well as a rigorous emissions regulation, under the New Source Performance Standards. The latter was applicable to new companies entering an area. Another innovation was the provision stating that citizens were entitled to take legal action against companies, individuals, or the government if found in violation of this Act. The standards and deadlines for motor vehicles emissions control and the ambient air quality proved to be beyond the existing technology of the time, which prevented the compliance with the established timetable. Therefore, they were extended in the Amendment of 1977 and more realistic goals were set.

About a decade of pollution-control legislative silence ensued after the 1977 Amendment, as environmental issues were not a priority during the Reagan Administration. It was only in 1990 that a new amendment was approved, "An Act to amend the Clean Air Act to provide for attainment and maintenance of health protective national ambient air quality standards, and for other purposes." Federal government extended in this bill deadlines for state compliance with ambient air standards, according to the level of air pollution in each area. The motor vehicles emissions standards were also raised to new limits in these most polluted areas, with a strict timetable of emission reductions to be enforced. The issue of acid rain and its impact on agriculture and forests was also tackled by the 1990 amendment as well as the need for emission reduction of chlorofluorocarbons (CFCs), which affect the stratospheric ozone. A "Best Available Control Technology" (BACT) mandate was issued, aiming to reduce levels of toxic air pollutants, beside a recommendation for the development and use of alternative fuels and reduction of sulfur in conventional fuels, since sulfur dioxide emissions are the main cause of acid rain. The Clean Air Act Amendments of 1990 also required that the EPA conduct periodic assessments of the benefits and costs of the Clean Air Act, issuing reports to Congress based on scientifically reviewed studies. Under section 812 of the 1990 Clean Air Act, the EPA is required to design and implement each study with the cooperation of the Departments of Labor and Commerce, in addition to a panel of outside experts, and to issue periodic reports such as "Benefits and Costs of the Clean Air Act, 1970 to 1990."

PRIMARY SOURCE

AIR QUALITY

The substantial reductions in air pollutant emissions achieved by the Clean Air Act translate into significantly improved air quality throughout the U.S. For sulfur dioxide, nitrogen oxides, and carbon monoxide, the improvements in air quality under the control scenario are assumed to be proportional to the estimated reduction in emissions. This is because, for these pollutants, changes in ambient concentrations in a particular area are strongly related to changes in emissions in that area. While the differences in control and no-control scenario air quality for each of these pollutants vary from place to place because of local variability in emissions reductions, by 1990 the national average improvements in air quality for these pollutants were: 40 percent reduction in sulfur dioxide, 30 percent reduction in nitrogen oxides, and 50 percent reduction in carbon monoxide.

Ground-level ozone is formed by the chemical reaction of certain airborne pollutants in the presence of sunlight. Reductions in ground-level ozone are therefore achieved through reductions in emissions of its precursor pollutants, particularly volatile organic compounds (VOCs) and nitrogen oxides (NO_X)² .The differences in ambient ozone concentrations estimated under the control scenario vary significantly from one location to another, primarily because of local differences in the relative proportion of VOCs and NO_X, weather conditions, and specific precursor emissions reductions. On a national average basis, ozone concentrations in 1990 are about 15 percent lower under the control scenario. For several reasons, this overall reduction in ozone is significantly less than the 30 percent reduction in precursor NO_X and 45 percent reduction in precursor VOCs. First, significant natural (i.e., biogenic) sources of VOCs limit the level of ozone reduction achieved by reductions in man-made (i.e., anthropogenic) VOCs. Second, current knowledge of atmospheric photochemistry suggests that ozone reductions will tend to be proportionally smaller than reductions in precursor emissions. Finally, the plume model system used to estimate changes in urban ozone for this study is incapable of handling long-range transport of ozone from upwind areas and multi-day pollution events in a realistic manner.

There are many pollutants which contribute to ambient concentrations of particulate matter. The relative contributions of these individual pollutant species to ambient particulate matter concentrations vary from one region of the country to the next, and from urban areas to rural areas. The most important particle species, from a human health standpoint, may be the fine particles which can be respired deep into the lungs. While some fine particles are directly emitted by sources, the most important fine particle species are formed in the atmosphere through chemical conversion of gaseous pollutants. These species are referred to as secondary particles. The three most important secondary particles are (1) sulfates, which derive primarily from sulfur dioxide emissions; (2) nitrates, which derive primarily from nitrogen oxides emissions; and (3) organic aerosols, which can be directly emitted or can form from volatile organic compound emissions. This highlights an important and unique feature of particulate matter as an ambient pollutant: more than any other pollutant, reductions in particulate matter are actually achieved through reductions in a wide variety of air pollutants. In other words, controlling particulate matter means controlling "air pollution" in a very broad sense. In the present analysis, reductions in sulfur dioxide, nitrogen oxides, volatile organic compounds, and directly-emitted primary particles achieved by the Clean Air Act result in a national average reduction in total suspended particulate matter of about forty-five percent by 1990. For the smaller particles which are of greater concern from a health effects standpoint (i.e., PM₁₀ and PM_2.5), the national average reductions were also about 45 percent.

Reductions in sulfur dioxide and nitrogen oxides also translate into reductions in formation, transport, and deposition of secondarily formed acidic compoundssuch as sulfate and nitric acid. These are the principal pollutants responsible for acid precipitation, or "acid rain." Under the control scenario, sulfur and nitrogen deposition are significantly lower by 1990 than under the no-control scenario throughout the 31 eastern states covered by EPA's Regional Acid Deposition Model (RADM). Percentage decreases in sulfur deposition range up to more than 40 percent in the upper Great Lakes and Florida-Southeast Atlantic Coast areas, primarily because the no-control scenario projects significant increases in the use of high-sulfur fuels by utilities in the upper Great Lakes and Gulf Coast states. Nitrogen deposition is also significantly lower under the control scenario, with percentage decreases reaching levels of 25 percent or higher along the Eastern Seaboard, primarily due to higher projected emissions of motor vehicle nitrogen oxides under the no-control scenario.

Finally, decreases in ambient concentrations of lightscattering pollutants, such as sulfates and nitrates, are estimated to lead to perceptible improvements in visibility throughout the eastern states and southwestern urban areas modeled for this study….

CONCLUSIONS AND FUTURE DIRECTIONS

First and foremost, these results indicate that the benefits of the Clean Air Act and associated control programs substantially exceeded costs. Even considering the large number of important uncertainties permeating each step of the analysis, it is extremely unlikely that the converse could be true.

A second important implication of this study is that a large proportion of the monetized benefits of the historical Clean Air Act derive from reducing two pollutants: lead and particulate matter….

SIGNIFICANCE

The first EPA report to Congress was based on retrospective studies addressing the benefits and costs associated with the 1970 and 1977 Amendments until 1990. A second, prospective study for the period of 1990 to 2020 is in progress.

The investments in research and development of new technologies, implementation of regulations, and monitoring mechanisms and agencies were initially borne mainly by the public sector. However, in order to comply with these new regulations, private companies also invested in pollution-abatement equipments, installation, operation, and maintenance. This represented approximately a $523 billion investment during this thirty-year period. Such costs were reflected in prices of merchandise and services and were ultimately paid by the final consumers, business owners, stockholders, and taxpayers. On the other hand, emissions of toxic and hazardous substances were significantly lower by 1990. For instance, sulfur dioxide emissions were reduced by 40 percent; nitrogen oxides were 30 percent lower; carbon monoxide emissions were reduced by 50 percent; and emissions of primary particulate matter were reduced by 75 percent. Another dangerous substance, a lead compound added to gasoline, was also reduced by 1990 by 99 percent. An important point to keep in mind is that such reductions in toxic emissions were achieved during a period of economic growth and a significant population increase, which alone are known factors of increased air and environmental pollution if left uncontrolled.

The Clean Air Acts of 1970 and 1977 adopted as criteria six pollutants—sulfur dioxide, tropospheric ozone, nitrogen oxides, carbon monoxide, lead, and particulate matter—to be given prioritized emission reductions. The total monetized benefits (money saved in medical care, reduced illness leaves, etc.) between 1970 and 1990 reached the trillions of dollars. Additional benefits include the reduction of acid rain and its damaging effect on forest and crops; reduction of corrosion of historical monuments, statues, and buildings; and a positive impact on aquatic and terrestrial ecosystems, improving the quality of freshwater in open reservoirs, rivers, and lakes.

FURTHER RESOURCES

Web sites

Intergovernmental Panel on Climate Change. "IPCC/TEAP Special Report: Safeguarding The Ozone Layer and The Global Climate System: Issues Related To Hydrofluorocarbons and Perfluorocarbons—Summary for Policymakers." Intergovernmental Panel on Climate Change. 〈http://www.ipcc.ch/press/SPM.pdf〉 (accessed March 17, 2006.)

Pearce, Fred. "Climate Change: Instant Expert." New Scientist, updated January 19, 2006. 〈http://www.newscientist.com/popuparticle.ns?id=in20〉 (accessed March 17, 2006.)

U.S. Environmental Protection Agency. "Clean Air Act: Title I—Air Pollution Prevention and Control." U.S. Environmental Protection Agency. 〈http://www.epa.gov/air/caa/title1.html£ia〉 (accessed March 17, 2006.)