Page 413 - Fundamentals of Air Pollution 3E

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Air Quality Criteria

and Standards

I. AIR QUALITY CRITERIA

Air quality criteria are cause-effect relationships, observed experimen-
tally, epidemiologically, or in the field, of exposure to various ambient
levels of specific pollutants. The relationships between adverse responses
to air pollution and the air quality levels at which they occur have been
discussed in Chapter 4 and illustrated in Table 4-5 and Fig. 4-10.
For any pollutant, air quality criteria may refer to different types of effects.
For example, Tables 22-1 through 22-6 list effects on humans, animals,
vegetation, materials, and the atmosphere caused by various exposures
to sulfur dioxide, particulate matter, nitrogen dioxide, carbon monoxide,
ozone, and lead. These data are from the Air Quality Criteria for these
pollutants published by the U.S. Environmental Protection Agency.
Criteria stipulate conditions of exposure and may refer to sensitive popu-
lation groups or to the joint effects of several pollutants. Air quality criteria
are descriptive. They describe effects that can be expected to occur wherever
the ambient air level of a pollutant reaches or exceeds a specific concentra-
tion for a particular time period. Criteria will change as new information
becomes available.

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