What causes the production of ozone as a secondary pollutant?

The production of ozone as a secondary pollutant is primarily driven by the reaction of nitrogen dioxide with sunlight and oxygen. This process occurs when nitrogen oxides (NOx) and volatile organic compounds (VOCs) are emitted into the atmosphere, often as a result of vehicle emissions and industrial activities. When these pollutants interact with sunlight, a series of reactions take place that ultimately lead to the formation of ozone at ground level.

Specifically, nitrogen dioxide (NO2) absorbs ultraviolet (UV) light from the sun, which causes it to break down into nitrogen oxide (NO) and a free oxygen atom (O). This free oxygen atom can then react with molecular oxygen (O2) present in the atmosphere to produce ozone (O3). Thus, the combination of sunlight and the presence of these precursors is crucial for the creation of ozone as a secondary pollutant, illustrating the complex interplay between various atmospheric components and sunlight in pollution formation.

The other options do not directly lead to the formation of ozone in the same manner. Carbon dioxide does not contribute to ozone formation in this context, and while incomplete combustion may produce various pollutants, it does not specifically lead to ozone production. High-temperature reactions between oxygen and nitrogen gases are more associated with the formation