What are some of the criteria air pollutants for which the USEPA has set NAAQS?

The criteria air pollutants for which the Environmental Protection Agency (EPA) has established National Ambient Air Quality Standards (NAAQS) are specific substances recognized for their potential to harm public health and the environment. These pollutants include well-documented substances like lead, particulate matter (PM) with diameters of 2.5 micrometers or less (PM2.5), ground-level ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and volatile organic compounds (VOCs) in some contexts.

The correct answer encompasses multiple criteria pollutants, illustrating that both lead and PM2.5, as well as ozone and sulfur dioxide, are part of the NAAQS established by the EPA. While carbon dioxide (CO2) is a significant greenhouse gas, it is not categorized as one of the criteria pollutants within NAAQS. The mention of PM10 also doesn't align as closely with the primary focus of the NAAQS, although it represents another form of particulate matter.

Thus, identifying that all the listed pollutants in the correct answer are indeed classified as criteria air pollutants reflects an understanding of the EPA’s role in regulating air quality for protection against harmful exposure. This answer underscores the importance of recognizing and addressing all relevant