Primary pollutants from burning coal include all of the following EXCEPT?

Primary pollutants are those that are directly emitted into the atmosphere from a source such as the combustion of fossil fuels like coal. When coal is burned, several harmful substances can be released, including sulfur dioxide, particulate matter, and carbon dioxide.

Sulfur dioxide is produced during the combustion of coal due to the sulfur content in the fuel. Particulate matter, made up of tiny particles that can be inhaled, is also released from burning coal. Carbon dioxide, while commonly associated with climate change as a greenhouse gas, is indeed a primary pollutant from this process due to the carbon content in coal.

Ozone, on the other hand, is not a primary pollutant from burning coal. Instead, it is considered a secondary pollutant, which means it is formed in the atmosphere through chemical reactions involving primary pollutants typically in the presence of sunlight, such as nitrogen oxides and volatile organic compounds.

Therefore, since ozone is not emitted directly from burning coal and is created through atmospheric processes, it is the correct choice for the question of which substance is not a primary pollutant from burning coal.