What are secondary pollutants?

Secondary pollutants are substances that are not emitted directly into the atmosphere but are formed through chemical reactions involving primary pollutants. When primary pollutants, such as nitrogen oxides or volatile organic compounds, interact with other atmospheric components under the influence of sunlight and heat, they can produce secondary pollutants. A common example of this is the formation of ozone at ground level, which occurs when sunlight catalyzes reactions among primary pollutants. This is significant because secondary pollutants often pose health and environmental risks, such as contributing to smog formation and respiratory problems. Understanding the distinction between primary and secondary pollutants is crucial for developing effective air quality management strategies.