### Question
How does the law define air pollutant?


### Answer
Under *42 U.S.C. § 7602*, **air pollutant** is defined as:

> any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive (including source material, special nuclear material, and byproduct material) substance or matter which is emitted into or otherwise enters the ambient air

#### Citation:
  - *42 U.S.C. § 7602*
  - Heading: **CHAPTER 85-AIR POLLUTION PREVENTION AND CONTROL > SUBCHAPTER III-GENERAL PROVISIONS**

