Air Quality (AQ)
Because O3 requires sunlight to form, it occurs in concentrations considered
serious primarily between the months of April and October.
Air quality is defined by numerous components regulated at the federal and
state level. For compatibility, the primary concerns are pollutants that limit
visibility, such as particulates, ozone, etc. and potential non‐attainment of
air quality standards that may limit future changes in operations at an
installation or the surrounding region.
Particulate Matter. Particulate matter consists of fine metal, smoke, soot,
and dust particles suspended in the air. Particulate matter is measured by
two sized: Coarse particles (PM10), or particles between 2.5 and
10 micrometers in diameter in size, and fine particles (PM2.5), or particles
less than 2.5 micrometers in diameter.
Key Terms
Technical Background
Attainment Area. An attainment area is a geographic area that meets the
National Ambient Air Quality Standards (NAAQS) for a criteria pollutant.
A number of factors can influence air quality in a region. These factors
include a variety of sources and types of pollutants, topographic conditions,
weather, and other factors. Community sources of dust, car emissions, and
air pollutants can also create adverse impacts on the environment and can
potentially limit Keesler AFB operations. Permits and funding for important
infrastructure projects can be delayed or denied in non‐attainment areas, or
projects may be subject to mitigation measures that increase the capital cost
of projects.
Criteria Pollutants. The criteria pollutants are the six principle pollutants
harmful to public health and the environment for which the Environmental
Protection Agency (EPA) has set NAAQS. The pollutants are: carbon
monoxide (CO), lead, nitrogen dioxide (NO2), ozone (O3), particulate matter
(PM), and sulfur dioxide (SO2).
National Ambient Air Quality Standards. The NAAQS are standards for
outdoor air pollutants established by the EPA under authority of the Clean
Air Act (CAA).
Under the Clean Air Act (CAA), the EPA established National Ambient Air
Quality Standards (NAAQS) for air pollutants. The NAAQS have been set for
the six criteria air pollutants. Air quality control regions (AQCR) are classified
either “attainment” or “nonattainment,” according to whether the
concentrations of criteria pollutants exceed the NAAQS or not.
Nonattainment designation categories are Marginal, Moderate, Serious,
Severe, and Extreme.
Nonattainment Area. A nonattainment area is a geographic area where air
pollution levels persistently exceed NAAQS, or that contributes to ambient
air quality in a nearby area that fails to meet standards. Designating an area
as nonattainment is a formal rulemaking process made by the EPA, typically
only after air quality standards have been exceeded for several consecutive
years.
Ozone. Ozone is a pungent, colorless, toxic gas with direct health effects on
humans, including respiratory and eye irritation and possible changes in lung
functions. Ozone is created when hydrocarbon and nitrogen oxides released
from vehicles and industrial sources react in the presence of sunlight.
Background Report
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