What do VOCs react with to form ozone and air pollutants?

Volatile Organic Compounds (VOCs) play a significant role in air quality and environmental health. They react with nitrous oxides (NOx) in the presence of sunlight to form ozone and other air pollutants. This process occurs primarily in the lower atmosphere, where sunlight acts as a catalyst for the chemical reactions between VOCs and NOx. The resulting ozone can contribute to smog formation, which has detrimental effects on both human health and the environment.

The presence of sunlight is essential in this reaction because it provides the energy needed for the chemical transformations. Without sunlight, the reaction would not take place effectively, leading to lower levels of ground-level ozone despite the presence of VOCs and NOx.

In contrast, other options such as carbon monoxide, water vapor, and hydrogen gas are not involved in the same chemical reaction that leads to ozone formation from VOCs. Each of these substances has different chemical behaviors and reactions, making them irrelevant in this specific context of ozone production in the atmosphere. This highlights the importance of understanding the specific interactions between pollutants in air quality management.