Pollution is unwanted, harmful stuff contaminating an environment. The race to develop clean energy is motivated by high levels of pollution that people fear are permanently damaging the earth's environment.

When you hear about pollution, you’re most likely hearing about chemical emissions into air or water that come from industrial processing. But pollution isn’t just environmental. Anything we think of as pure can be contaminated by pollution polluted, whether that's a lake or an idea. If your mother finds you reading trashy magazines instead of doing your homework, she might worry about the pollution of your mind.

Definitions of pollution
  1. noun
    undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities
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    biodegradable pollution
    pollution that is rendered harmless by natural processes and so causes no permanent harm
    nonbiodegradable pollution
    pollution that accumulates in the environment and may appear in the food chain
    air pollution
    pollution of the atmosphere
    noise pollution, sound pollution
    annoying and potentially harmful environmental noise
    thermal pollution
    harm to lakes and rivers resulting from the release of excessive waste heat into them
    water pollution
    pollution of the water in rivers and lakes
    acid precipitation, acid rain
    rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water
    industrial air pollution
    pollution resulting from an industrial plant discharging pollutants into the atmosphere
    miasm, miasma
    unhealthy vapors rising from the ground or other sources
    small-particle pollution
    air pollution caused by fine particles of soot (as from power plants or diesel engines)
    smog, smogginess
    air pollution by a mixture of smoke and fog
    type of:
    impureness, impurity
    the condition of being impure
    environmental condition
    the state of the environment
  2. noun
    the state of being polluted
    synonyms: befoulment, defilement
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    type of:
    dirtiness, uncleanness
    the state of being unsanitary
  3. noun
    the act of contaminating or polluting; including (either intentionally or accidentally) unwanted substances or factors
    synonyms: contamination
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    the removal of contaminants
    dust contamination
    the act of contaminating with dust particles
    type of:
    dirtying, soiling, soilure
    the act of soiling something
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