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Air Quality Planning and Standards

Air Pollution Monitoring

The basic mission of the Office of Air Quality Planning and Standards is to preserve and improve the quality of our nation's air. To accomplish this, OAQPS must be able to evaluate the status of the atmosphere as compared to clean air standards and historical information. The following are some of the topics associated with monitoring air pollution:

Air Quality Standards

OAQPS manages EPA programs to improve air quality in areas where the current quality is unacceptable and to prevent deterioration in areas where the air is relatively free of contamination. To accomplish this task, OAQPS establishes the National Ambient Air Quality Standard (NAAQS) for each of the criteria pollutants.

There are two types of standards -- primary and secondary. Primary standards protect against adverse health effects; secondary standards protect against welfare effects, such as damage to farm crops and vegetation and damage to buildings. Because different pollutants have different effects, the NAAQS are also different. Some pollutants have standards for both long-term and short-term averaging times. The short-term standards are designed to protect against acute, or short-term, health effects, while the long-term standards were established to protect against chronic health effects.

This NAAQS table lists all criteria pollutants and standards.

Air Quality Trends Report

Each year EPA examines air pollution trends of each of the six principal pollutants in this country. A yearly EPA document titled National Air Quality and Emissions Trends Report gives a detailed analysis of changes in air pollution levels over the last 10 years time, plus a summary of the current air pollution status.

Ambient Monitoring Technology Information Center (AMTIC)

The Ambient Monitoring Technology Information Center (AMTIC) site is part of the TTNWeb. AMTIC is centered around the exchange of ambient monitoring related information. It contains all Federal Regulations pertaining to ambient monitoring, as well as ambient monitoring QA/QC related information and some information on ambient monitoring related publications. There is also available information on ambient monitoring news, field and laboratory studies of interest and available related training.


A geographic area that meets or does better than the national ambient air quality standard is called an attainment area; an area that doesn't meet this standard is called a nonattainment area.

The Green Book site provides a look at nonattainment areas.

CICA (U.S. - Mexico Information Center on Air Pollution)

¡Bienvenido a CICA! The U.S. - Mexico Information Center on Air Pollution (CICA) is an organization that provides technical support and assistance in evaluating air pollution problems along the Mexico - U. S. Border. Our bilingual CICA site discusses the organization and its projects in detail.

Criteria Pollutants

A few air pollutants, called criteria air pollutants, are common throughout the United States. These pollutants can injure health, harm the environment and cause property damage. The current criteria pollutants are:

  • Carbon Monoxide (CO)
  • Lead (Pb)
  • Nitrogen Dioxide (NO2)
  • Ozone (O3)
  • Particulate matter (PM)
  • Sulfur Dioxide (SO2)

A good overview discussion of criteria pollutants can be found in the Plain English Guide To The Clean Air Act. Look to The Green Book site for a more detailed discussion. The EPA Air Trends Website also discusses the Six Principal Pollutants.


The Air Quality Subsystem (AQS), contains air pollution and meteorological measurements from EPA, state and local agency monitoring stations. The Air Facility System (AFS) contains compliance and permit data for stationary sources regulated by EPA, state and local air pollution agencies. The AirData Web site gives you access to air pollution data (annual summary data) for the entire United States by allowing you to produce reports and maps of air pollution data based on criteria that you specify.

Hazardous/Toxic Air Pollutants

Toxic air pollutants are substances in the air that are toxic or hazardous to humans. These pollutants can increase your chances of experiencing health problems, and cause ecological impacts.

The Air Toxics Website is a good source for further information, including detailed information about all 189 hazardous air pollutants at the The Health Effects Notebook for Hazardous Air Pollutants site.

Monitor Types

The Clean Air Act requires every state to establish a network of air monitoring stations for criteria pollutants, using criteria set by OAQPS for their location and operation. The monitoring stations in this network are called the State and Local Air Monitoring Stations (SLAMS). The states must provide OAQPS with an annual summary of monitoring results at each SLAMS monitor, and detailed results must be available to OAQPS upon request. To obtain more timely and detailed information about air quality in strategic locations across the nation, OAQPS established an additional network of monitors: the National Air Monitoring Stations (NAMS). NAMS sites, which are part of the SLAMS network, must meet more stringent monitor siting, equipment type, and quality assurance criteria. NAMS monitors also must submit detailed quarterly and annual monitoring results to OAQPS.

A third type of monitor, the Special Purpose Monitor (SPMS), is used by State and local agencies to fulfill very specific or short-term monitoring goals.

The 1990 Amendments to the Clean Air Act also requires a fourth category of a monitoring station, the Photochemical Assessment Monitoring Station (PAMS), which measures ozone precursors (approximately 60 volatile hydrocarbons and carbonyl).

The Ambient Monitoring Technology Information Center (AMTIC) site is centered around the exchange of ambient monitoring related information.

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