thumb|[[Surface runoff, also called nonpoint source pollution, from a farm field in Iowa, the United States during a rainstorm. Topsoil, as well as farm fertilizers and other potential pollutants, runoff unprotected farm fields when heavy rains occur.|400x400px]]
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts). Pollutants result in environmental pollution or become of public health concern when they reach a concentration high enough to have significant negative impacts.
A pollutant may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with resources used by humans, human health or wellbeing, or property values. Some pollutants are biodegradable and therefore will not persist in the environment in a long term. However, the degradation products of some pollutants are themselves pollutants such as DDE and DDD produced from the degradation of DDT.
Pollution has widespread negative impact on the environment.
Stock pollutants
Pollutants, towards which the environment has low absorptive capacity are called stock pollutants. Scientists have officially deemed that the planetary boundaries safe chemical pollutant levels (novel entities) have been surpassed.
- Particulate matter (PM)
- Persistent organic pollutants (POPs)
- Polycyclic aromatic hydrocarbons (PAHs)
- Volatile organic compounds (VOCs)
Light pollutant
Light pollution is the impact that anthropogenic light has on the visibility of the night sky. It also encompasses ecological light pollution which describes the effect of artificial light on individual organisms and on the structure of ecosystems as a whole.
thumb|The night sky viewed from Luhasoo bog, [[Estonia with light pollution in the background]]
Zones of influence
Pollutants can also be defined by their zones of influence, both horizontally and vertically.
United States
Clean Air Act standards. Under the Clean Air Act, the National Ambient Air Quality Standards (NAAQS) are developed by the Environmental Protection Agency (EPA) for six common air pollutants, also called "criteria pollutants": particulates; smog and ground-level ozone; carbon monoxide; sulfur oxides; nitrogen oxides; and lead. The National Emissions Standards for Hazardous Air Pollutants are additional emission standards that are set by EPA for toxic air pollutants.
Clean Water Act standards. Under the Clean Water Act, EPA promulgated national standards for municipal sewage treatment plants, also called publicly owned treatment works, in the Secondary Treatment Regulation. National standards for industrial dischargers are called Effluent guidelines (for existing sources) and New Source Performance Standards, and currently cover over 50 industrial categories. In addition, the Act requires states to publish water quality standards for individual water bodies to provide additional protection where the national standards are insufficient.
RCRA standards. The Resource Conservation and Recovery Act (RCRA) regulates the management, transport and disposal of municipal solid waste, hazardous waste and underground storage tanks.
See also
- Conventional pollutant - U.S. Clean Water Act
- List of environmental issues
- Pollutant Standards Index
- Pollution