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Air Quality
General information about air quality

Air pollution has been linked to a number of health problems like asthma, heart disease, and breathing problems among others. National air quality has improved over the last 20 years, but there are still many challenges in protecting public health and the environment from air quality problems.

In 1970, the Clean Air Act was signed into law. Under this law, the Environmental Protection Agency (EPA) sets limits or standards on how much of a pollutant can be in the air for six “criteria” pollutants:

  • carbon monoxide
  • lead
  • nitrogen dioxide
  • sulfur dioxide
  • ozone
  • particulate matter (PM)

These standards, called the National Ambient Air Quality Standards (NAAQS), help protect public health and the environment.

The Clean Air Act requires states to develop a set of the regulations, programs and policies to clean up polluted areas. Environmental agencies have the primary responsibility of monitoring air quality and population exposure to air pollutants. Since the 1970s, State and Local Ambient Monitoring Stations (SLAMS) have represented the majority of all criteria pollutant monitoring across the nation. The Air Quality System (AQS) database contains this ambient air pollution data. The data are collected by EPA, state, local, and tribal air pollution control agencies from stations across the United States.

The air quality indicators presented here are estimates collected and generated by the EPA. The estimates consist of statistical combinations of monitor and modeled data that predict air pollutant concentrations across an entire spatial domain of interest. The advantage of using estimates is that it helps to fill in the temporal and spatial gaps that exist in data that comes purely from air monitoring stations. Furthermore, the data are supported by a comprehensive quality assurance program, ensuring good data of known quality.

The Oregon EPHT program currently collects data about PM 2.5 and ozone. Tracking these pollutants will enhance the ability of agencies to estimate the impacts of PM and ozone on health by improving the accessibility of air quality and health outcome data, and by developing practical and systematic methods that can be applied across geographic areas, identifying high risk populations, or generating new research questions.