What are the six primary air pollutants as defined by the NAAQS?

What are the six primary air pollutants as defined by the NAAQS?

• A. Particulate matter, ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead
• B. Particulate matter, ozone, methane, sulfur dioxide, nitrogen dioxide, and lead
• C. Particulate matter, ozone, carbon monoxide, nitrogen dioxide, ammonia, lead
• D. Ozone, carbon monoxide, methane, sulfur trioxide, nitrous oxide, lead

Answer: (A)

The six pollutants targeted by the NAAQS are the pollutants the EPA uses to set the National Ambient Air Quality Standards because of their known health and welfare impacts. These six are particulate matter, ground-level ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. Particulate matter includes tiny particles that can penetrate the lungs and even the bloodstream. Ozone at ground level forms from reactions between NOx and volatile organic compounds in sunlight and can irritate airways. Carbon monoxide is a colorless, odorless gas that can reduce the blood’s oxygen delivery. Sulfur dioxide comes mainly from burning sulfur-containing fuels and can irritate the airways and contribute to acid rain. Nitrogen dioxide arises from combustion and is a component of smog and a factor in respiratory problems. Lead is a toxic metal that affects neurological development, especially in children. Other substances like methane, ammonia, or nitrous oxide are not part of the six NAAQS criteria pollutants, though they may be important in other contexts.

The six pollutants targeted by the NAAQS are the pollutants the EPA uses to set the National Ambient Air Quality Standards because of their known health and welfare impacts. These six are particulate matter, ground-level ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. Particulate matter includes tiny particles that can penetrate the lungs and even the bloodstream. Ozone at ground level forms from reactions between NOx and volatile organic compounds in sunlight and can irritate airways. Carbon monoxide is a colorless, odorless gas that can reduce the blood’s oxygen delivery. Sulfur dioxide comes mainly from burning sulfur-containing fuels and can irritate the airways and contribute to acid rain. Nitrogen dioxide arises from combustion and is a component of smog and a factor in respiratory problems. Lead is a toxic metal that affects neurological development, especially in children. Other substances like methane, ammonia, or nitrous oxide are not part of the six NAAQS criteria pollutants, though they may be important in other contexts.