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750 Introduction to Industrial Hygiene
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Outdoor Air Quality

The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards for six common air pollutants.

Air Quality 101

These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are:

  1. particle pollution (often referred to as particulate matter),
  2. ground-level ozone,
  3. carbon monoxide,
  4. sulfur oxides,
  5. nitrogen oxides, and
  6. lead.

These pollutants can harm your health and the environment, and cause property damage.

Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards.

Knowledge Check Choose the best answer for the question.

2-6. Of the six common air pollutants, which are the most widespread health threats.