- Waste released or emitted to the environment. The term is commonly used in referring to discharges of gases and particles to the atmosphere, i.e., air pollutants, and also is used in referring to particles or energy released radioactively. Sometimes the term is used broadly, encompassing any pollutant discharge.
- The release or giving out of a gas, light or heat. An automobile releases uncombusted or partially oxidized hydrocarbon emissions from its tailpipe when the engine is running. Atoms in an excited state often emit light in order to reach a lower energy state. These emissions can be used to determine the presence of the atoms in a sample. [Journal of Environmental Economics and Management; v. 25, 177-195; 1993.] [Science; v. 26; 5151, 1255-1257; 1994.] Source: Atmospheric Chemistry Glossary