Kara Sears
The Clean Air Act, which was last amended in 1990, requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants (criteria air pollutants) that are harmful to public health and the environment. These pollutants are typically emitted from many sources in industry, mining, transportation, electricity generation, and agriculture. The NAAQS are health-based and the EPA sets two types of standards: primary and secondary. The primary standards are designed to protect the health of 'sensitive' populations such as asthmatics, children, and the elderly, while the secondary standards are concerned with protecting the environment, including visibility, damage to crops, vegetation, buildings, and animals. The EPA established the NAAQS according to Sections 108 and 109 of the Clean Air Act, which also requires the EPA to periodically review and revise, as appropriate, the criteria and NAAQS for a given listed pollutant or class of pollutants.
| Characteristics | Values |
|---|---|
| Law that created the standards | Clean Air Act |
| Year of creation | 1970 |
| Last amended | 1990 |
| Administering body | United States Environmental Protection Agency (EPA) |
| Number of criteria pollutants | 6 |
| Criteria pollutants | Ozone (O3), atmospheric particulate matter (PM2.5/PM10), lead (Pb), carbon monoxide (CO), sulfur oxides (SOx), nitrogen oxides (NOx) |
| Units of measurement | Parts per million (ppm), parts per billion (ppb), micrograms per cubic meter of air (µg/m3) |
| Frequency of review | Every 5 years |
| Penalties for non-attainment | Withholding of federal highway funds |
Explore related products
What You'll Learn
The Clean Air Act
- Ozone (O3)
- Atmospheric particulate matter (PM2.5/PM10)
- Lead (Pb)
- Carbon monoxide (CO)
- Sulfur oxides (SOx)
- Nitrogen oxides (NOx)
The NAAQS are selected by the U.S. EPA Administrator at the conclusion of a public process that takes about five years for completion. The process starts with a comprehensive review of the relevant scientific literature, which is summarized in the Integrated Science Assessment (ISA). Based on the ISA, the EPA staff performs a risk and exposure assessment, which is then summarized in the Risk and Exposure Assessment (REA) document. The third document, the Policy Assessment (PA), integrates the findings and conclusions of the ISA and REA into a policy context. Each of these three documents is released for public comment and peer review by the Clean Air Scientific Advisory Committee (CASAC), a subcommittee of the EPA. The committee’s role is to peer review the NAAQS documents, ensure that they reflect the thinking of the scientific community, and advise the Administrator on the technical and scientific aspects of standard setting. Once all three documents are final, they are given to the U.S. EPA Administrator to use in selecting a proposed NAAQS, which is released through the Federal Register for public comment. Following the close of the comment period, the Administrator considers the comments received, makes changes to the proposed NAAQS if warranted, and publishes the final NAAQS in the Federal Register.
The Law of Inertia: Who Was the Real Pioneer?
You may want to see also
Explore related products
Primary standards
The Clean Air Act, last amended in 1990, requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants, or "criteria pollutants", that are common in outdoor air, harmful to public health, and harmful to the environment. The six criteria air pollutants (CAPs) are:
- Ozone (O3)
- Atmospheric particulate matter (PM2.5/PM10)
- Lead (Pb)
- Carbon monoxide (CO)
- Sulfur oxides (SOx)
- Nitrogen oxides (NOx)
The Clean Air Act established two types of national air quality standards: primary standards and secondary standards. Primary standards are designed to protect the health of "sensitive" populations such as asthmatics, children, and the elderly. They are defined as the maximum amount of a pollutant averaged over a specified period that can be present in outdoor air without harming public health. For example, the primary standard for carbon monoxide was set at 9 ppm averaged over an 8-hour period and 35 ppm over a 1-hour period.
The statute describes primary standards as:
> [...] ambient air quality standards, the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health.
The Administrator is required to complete a thorough review of the criteria and standards at five-year intervals and make revisions as appropriate. The Administrator may also review and revise criteria or promulgate new standards earlier or more frequently than required. For example, the Administrator was required to promulgate a national primary ambient air quality standard for NO2 concentrations over a period of not more than 3 hours by August 7, 1977, unless it was found that there was no significant evidence that such a standard was requisite to protect public health.
Federal law requires that all states attain the NAAQS. Nonattainment areas must develop plans to attain the NAAQS, and attainment areas must develop plans to maintain attainment. Failure of a state to reach attainment of the NAAQS by the target date can trigger penalties, including withholding of federal highway funds.
Hubble's Law: The Man Behind the Cosmic Theory
You may want to see also
Explore related products
Secondary standards
The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants, or "criteria pollutants", that are common in outdoor air, harmful to public health and the environment, and that come from numerous and diverse sources. The statute established two types of national air quality standards: primary standards and secondary standards.
The EPA set the first NAAQS for carbon monoxide in 1971. The primary standard was set at 9 ppm averaged over an 8-hour period and 35 ppm over a 1-hour period. In 1979, 1984, 1991, and 1994, the EPA reviewed and assessed the current scientific literature concerning CO. In 1984, after the review, the EPA decided to remove the secondary standard for CO due to a lack of significant evidence of adverse environmental impacts.
In 2011, the EPA decided that the current NAAQS for CO were sufficient and proposed to keep the existing standards. The EPA is strengthening monitoring requirements for CO by calling for CO monitors to be placed in strategic locations near large urban areas. In 2012, the EPA "took final action" to maintain the existing NAAQS.
The Clean Air Act requires the EPA to review the standards and the science behind them periodically to determine whether changes are warranted. The Administrator may review and revise criteria or promulgate new standards earlier or more frequently than required.
Manifesting with Vision Boards: Law of Attraction
You may want to see also
Explore related products
EPA's role
The Clean Air Act, which was last amended in 1990, requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants, or "criteria pollutants", that are harmful to public health and the environment. These pollutants are typically emitted from many sources in industry, mining, transportation, electricity generation, and agriculture. The six criteria air pollutants (CAP) are:
- Ozone (O3)
- Atmospheric particulate matter (PM2.5/PM10)
- Lead (Pb)
- Carbon monoxide (CO)
- Sulfur oxides (SOx)
- Nitrogen oxides (NOx)
The Clean Air Act identifies two types of national ambient air quality standards: primary standards and secondary standards. The primary standards are designed to protect the health of 'sensitive' populations such as asthmatics, children, and the elderly. The secondary standards are concerned with protecting the environment, including visibility, damage to crops, vegetation, buildings, and animals.
The EPA establishes the NAAQS through a comprehensive public process that takes about five years for completion. The process starts with a review of the relevant scientific literature, which is summarized in the Integrated Science Assessment (ISA). Based on the ISA, the EPA performs a risk and exposure assessment, which is documented in the Risk and Exposure Assessment (REA). The third document, the Policy Assessment (PA), integrates the findings and conclusions of the ISA and REA into a policy context and provides lines of reasoning for the retention or revision of the existing NAAQS, as well as alternative standards. Each of these three documents is released for public comment and peer review by the Clean Air Scientific Advisory Committee (CASAC), a subcommittee of the EPA. Members of CASAC are appointed by the EPA Administrator for their expertise in the relevant subject areas.
Once all three documents are finalized, they are submitted to the EPA Administrator, who uses them to select a proposed NAAQS, which is released through the Federal Register for public comment. After considering the comments received, the Administrator makes any necessary changes to the proposed NAAQS and publishes the final standards in the Federal Register.
The Clean Air Act also requires the EPA to periodically review the NAAQS and the science behind them to determine whether changes are warranted. The Administrator may review and revise the criteria or promulgate new standards as needed. The EPA's Data Requirements Rule for the 2010 1-Hour Sulfur Dioxide (SO2) Primary National Ambient Air Quality Standard is an example of the EPA's ongoing work in this area.
Hammurabi's Code: Social Division and Inequality
You may want to see also
Explore related products
NAAQS review process
The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants, called "criteria pollutants". These pollutants are common in outdoor air, considered harmful to public health and the environment, and come from numerous and diverse sources. The Clean Air Act also requires the EPA to periodically review the standards and the science behind them to determine whether changes are warranted.
The NAAQS review process has evolved over time. In December 2005, the EPA Deputy Administrator requested that the Office of Air and Radiation (OAR) and the Office of Research and Development (ORD) conduct a "top-to-bottom review" of the process the Agency uses in setting and reviewing NAAQS. Advice and recommendations were requested from current and former members of the Clean Air Scientific Advisory Committee (CASAC) and other stakeholder groups with substantial experience with the NAAQS review process. On April 3, 2006, the working group issued a report outlining their conclusions and recommendations.
On June 27, 2006, the EPA held a public workshop to discuss the process the Agency uses to review the NAAQS. The workshop provided the public with the opportunity to present their views on the review process and to discuss it with EPA officials.
On May 21, 2009, Administrator Lisa P. Jackson called for key changes to the NAAQS review process, including reinstating a policy assessment document that contains staff analyses of the scientific bases for alternative policy options for consideration by senior Agency management prior to rulemaking.
The NAAQS review process typically involves three types of assessments:
- Integrated Science Assessment (ISA): This is a comprehensive review, synthesis, and evaluation of the most policy-relevant science, including key science judgments that are important to inform the development of risk and exposure assessments.
- Risk/Exposure Assessment (REA): This assessment draws upon information and conclusions presented in the ISA to develop quantitative characterizations of exposures and associated risks to human health or the environment. It includes a characterization of the uncertainties associated with such estimates.
- Policy Assessment (PA): This assessment provides a transparent staff analysis of the scientific basis for alternative policy options for consideration by senior EPA management prior to rulemaking. It helps "bridge the gap" between the Agency's scientific assessments and the judgments required of the EPA Administrator in determining whether to retain or revise the NAAQS.
The Clean Air Act requires the EPA to review the NAAQS for each pollutant every five years. During this review, the EPA can decide to keep the existing standards or revise them. Congress intended the Clean Air Act to protect public health by establishing these reviews, allowing continual adjustments to pollution limits according to the best available information.
The Process of Creating a Bill
You may want to see also
Frequently asked questions
The Clean Air Act, which was last amended in 1990.
NAAQS are air quality standards designed to protect public health and the environment.
NAAQS set standards for six principal pollutants, also known as "criteria pollutants": ozone, particulate matter, lead, carbon monoxide, nitrogen dioxide, and sulfur dioxide.
