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Secondary Pollutants

Definition

Secondary pollutants are harmful substances that form in the atmosphere through chemical reactions involving primary pollutants and other atmospheric components. They contribute to air pollution indirectly.

Analogy

Imagine you have two colors of paint - blue and yellow. When you mix them together, they create green paint. Similarly, secondary pollutants are like the "green paint" formed when different chemicals react with each other in the atmosphere.

Related terms

Primary Pollutants: Primary pollutants are directly emitted into the environment from human activities or natural sources. Unlike secondary pollutants, they do not require any chemical reactions to form.

Ozone (O3): Ozone is a secondary pollutant formed by complex chemical reactions involving sunlight, nitrogen oxides (NOx), volatile organic compounds (VOCs), and other pollutants. It is a major component of smog.

Acid Rain: Acid rain is a secondary pollutant formed when primary pollutants, such as sulfur dioxide (SO2) and nitrogen oxides (NOx), react with water vapor in the atmosphere. It can have harmful effects on ecosystems, buildings, and human health.