the standards for pollutants are based on ___.\ncongresss opinion\nthe presidents opinion\nscientific…

Brief Explanations:

Pollutant standards are established through scientific studies. These studies analyze the effects of pollutants on human health and the environment. Congress, the President, and public opinion can influence the regulatory process, but the core basis is scientific evidence. For example, the Clean Air Act in the U.S. relies on scientific data to set National Ambient Air Quality Standards.

Answer:

scientific studies