National Ambient Air Quality Standards Article Index for
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Information About

National Ambient Air Quality Standards




NAAQS requires the EPA to set standards on six criteria Pollutant s:

# Ozone (O3)
# Particulate Matter
  • PM10, course particles: 2.5 Micrometre s (μm) to 10 μm in size (although current implementation includes all particles 10 μg or less in the standard)

  • PM2.5, fine particles: 2.5 μm in size or less

  • # Carbon Monoxide (CO)

# Sulfur Dioxide (SO2)
# Nitrogen Oxide s (NOx)
# Lead (Pb)


STANDARDS


Each standard has its own criteria for how may times it may be exceeded, in some cases using a three year average.

As of June 15, 2005, the 1-hour ozone standard no longer applies to areas designated with respect to the 8-hour ozone standard (which includes most of the United States, except for portions of 10 states).

Source: USEPA


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