The first Clean Air Act (CAA) was enacted in 1963 authorizing the establishment of national program that is responsible for addressing issues related to air in the environment. Another mandate for CAA was to facilitate the translation of research findings into actionable techniques for reducing air pollution. The second CAA resulted from a revision of the first CAA in 1970(Vicario, & Ohliger, 2015). The revised CAA included the definition of EPA’s responsibilities for improving and protecting the quality of air in the United States and the stratospheric ozone layer. Additional legislation was included in the CAA in 1977 and 1990. The inclusion subdivided the country into air quality regions as well as setting the concentration standard for various air pollutants. The main objective was to minimize the amount pollutants in the air thus reducing the human health risks. CAA regulates the ambient air pollutants such as particulates, ozone, sulphur oxides (SOx), nitrogen oxides (NOx), Lead (Pb), Hydrocarbons (HCs) and Carbon Monoxide (CO).
The environmental law tasked the relevant institutions with the responsibility of developing technology-based emission standards for specific industry categories (SICs).The law specify the amount of pollutant a specific industry is allowed to emit into the air as well as compelling industries to state the technology they use(Vicario, & Ohliger, 2015). Congress included air toxics such as polychlorinated biphenyls and mercury in the 1990 amendment. The amendment also required environmental protection agency to identify industrial sources of toxic air based on the 187 list of air pollutants. Subsequently, the agency initiates steps of ensuring the industry change production processes or install control mechanism in order to significantly reduce air pollution. The last amendment also included programs of ensuring that the use of chemicals that lead to the emission of gases that deplete the ozone layer was phased in the production process.
Major provisions of the Clean Air Act (CAA)
The environmental law Clean Air Act was codified as 42 U.S.C et seq. The law sort to protect the environment and human health from emissions that pollute ambient, or outdoor air. The 1990 amendment ensured that the environmental law consisted of four major provisions: requirement for the prevention of catastrophic releases, standards for stationary “area source”, health-based standards and maximum achievable control technology (MACT)(McCarthy, et al., 2011).
Maximum Achievable Control Technology (MACT): This is the technology-based emission standards developed by EPA. The agency is mandated to establish standards based on sources of 187 pollutants listed in the CAA. In addition, the agency is required to categories the source of pollutants based on the established emission standards(McCarthy, et al., 2011). Environmental protection agency is tasked with the responsibility of reviewing and revising emission standards periodically, generally after every eight years. It is also prerogative for the agency to respond to the petitions, add or remove source categories from the 187 pollutants listed. The environmental law requires EPA to establish emission standards for listed sources of pollutants. The set standards must achieve the “Maximum degree of reduction in emissions”. The establishment of the set standards must factor in the non-air-quality and economic factors in the implementation process. One requirement of MACT standards was that “it shall not be less stringent than the most stringent emissions level that is achieved in practice by the best controlled similar source.”
Health-based standards: This is the second major provision of the environmental law. It requires the EPA to establish health-based standards that addressed the residual threats of adverse environmental and health effect existing after the implementation of MACT. The law directed the EPA in consultation with Surgeon General of the United States, prepare and submit a report to Congress detailing influence of residual risks to the public health and recommended legislation to minimize the risks(McCarthy, et al., 2011). In addition, the environmental law requires EPA to contract National Academy of Sciences (NAS) to conduct risk assessment, establish a Risk Assessment and Management Commission to inquire and prepare a report on the effects of policy and effective use of risk assessment and management
Technology-based and health-based programs: This is the third major provision addressing the problem of major source of hazardous air pollution. The law requires EPA to set standards for stationary “area sources” identified to cause threat or adverse effect to the environment and human health(McCarthy, et al., 2011). This provision mandated the EPA to set regulations that controls stationary area sources considered liable for emitting 90 % of the identified thirty hazardous air pollutants that poses greater risks to the urban dwellers. Unlike MACT, EPA may formulate standards that imposes less stringent and readily available control technologies.
Catastrophic releases of air toxics: The law mandated the EPA to constitute an independent Chemical Safety and Hazard Investigation Board. The independent board is tasked with the responsibility of inquiring into accidents that leads to emission of hazardous substances, carrying out research and developing reports that include recommendations on how to prevent sudden catastrophic releases as well as minimizing the risk of accidents(McCarthy, et al., 2011). The law also require EPA to provide guidelines for detecting, preventing and correcting catastrophic releases of hazardous substance by major sources.
Economic impact of the law
Analysis indicated that the total economic value of CAA environmental law for the 20-year period ranged between 5.6 and 49.4 trillion dollars. The mean estimated economic benefits was estimated to be 22.2 trillion dollars. During the 20 year period, the implementation and compliance cost was estimated to be 0.5 trillion dollars (Lockwood, 2012). Therefore, the net economic benefit was estimated to range between 5.1 and 48.9 trillion dollars, while the mean estimates to be at 21.7 trillion dollars.
Table 1: Economic benefits of Clean Air Act (Source: Lockwood, 2012)
Annual effect avoided
Effect value per case
Ischemic heart disease hospitalization
Congestive heart failure
particulate matter and carbon monoxide
Chronic obstructive pulmonary disease and pneumonia hospitalization
Scientific studies have proved that global warming is a real threat to the world. Many scientific studies on the global warming have highlighted environmental factors that have continuous change over a period of time. The environmental changes include rising in global temperature that leads melting of ice in mountain tops and Iceland and subsequently rising of sea level thus causing floods. The United States should adopt other environmental laws and policies to reduce the emission of greenhouse gas emission. These laws should ensure that industries emitting greenhouse gases such as carbon dioxide beyond the stipulated standards are compelled to pay countries that produce less carbon dioxide through a process of carbon sequential.