Answer:
The National Ambient Air Quality Standards (NAAQS) are maximum allowable levels for 6 harmful pollutants.
Explanation:
The EPA (United States Environmental Protection Agency) sets National Ambient Air Quality Standards for pollutants considered harmful to the population and the environment. EPA includes two standards, one includes public health protection, and the other damage to animals, crops, vegetation, and buildings. The standards must be revised periodically, they are classified by averaging time, level and form.
The EPA has set National Ambient Air Quality Standards for six principal pollutants:
Carbon Monoxide: is harmful when inhaled in large amounts. CO is released when something is burned. The greatest sources of CO to outdoor air are cars, is recommended not to be exceeded more than once per year.
Lead: sources are waste incinerators, utilities, and lead-acid battery manufacturers and piston-engine aircraft operating on leaded aviation fuel.
Nitrogen Dioxide (NO2): gets in the air from the burning of fuel
Ozone: at ground level is a harmful air pollutant, is the main compound in smog.
Particulate Matter (PM) Pollution: a mixture of solid particles and liquid droplets that can be emitted directly from a source, for example fires, construction sites or industries and automobiles.
Sulfur Dioxide: they come from fossil fuel combustion
