Which of the following is NOT a criteria pollutant?Question 14Select one:a.carbon monoxideb.volatile organic compoundsc.sulfur dioxided.ozone

To determine which of the options is NOT a criteria pollutant, we need to understand what criteria pollutants are. Criteria pollutants are a group of air pollutants that are regulated by the Environmental Protection Agency (EPA) due to their harmful effects on human health and the environment.

Let's analyze each option:

a. Carbon monoxide: Carbon monoxide (CO) is a criteria pollutant. It is produced by the incomplete combustion of fossil fuels and is known to be harmful to human health.

b. Volatile organic compounds (VOCs): VOCs are also criteria pollutants. They are emitted from various sources such as industrial processes, vehicle emissions, and solvents. VOCs contribute to the formation of ground-level ozone and can have adverse health effects.

c. Sulfur dioxide: Sulfur dioxide (SO2) is another criteria pollutant. It is primarily emitted from burning fossil fuels, particularly in power plants and industrial processes. SO2 can cause respiratory problems and contribute to the formation of acid rain.

d. Ozone: Ozone (O3) is not a criteria pollutant. While it is a harmful air pollutant, it is not included in the list of criteria pollutants regulated by the EPA. Ground-level ozone is formed when VOCs and nitrogen oxides (NOx) react in the presence of sunlight. It can cause respiratory issues and other health problems.

Based on this analysis, the correct answer is d. ozone.