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The Plain English Guide To The Clean Air Act

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The Common Air Pollutants (Criteria Air Pollutants)

Ozone (ground-level ozone is the principal component of smog)

VOCs* (volatile organic compounds); smog-formers

* All VOCs contain carbon (C), the basic chemical element found in living beings. Carbon-containing chemicals are called organic. Volatile chemicals escape into the air easily. Many VOCs, such as the chemicals listed in the table, are also hazardous air pollutants, which can cause very serious illnesses. EPA does not list VOCs as criteria air pollutants, but they are included in this list of pollutants because efforts to control smog target VOCs for reduction.

Nitrogen Dioxide (One of the NOx); smog-forming chemical

Carbon Monoxide (CO)

Particulate Matter (PM-10); (dust, smoke, soot)

Sulfur Dioxide

Lead

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