How to say "contamination" in Japanese

• 汚染おせんJLPT N3approx.Common
  noun, suru verb, transitive verb, intransitive verbThe general word for contamination: pollution of the environment, or the contamination of food, water, or materials by harmful substances. When unsure which word to use, this is usually the safest choice.
  汚染おせんが地球ちきゅうを傷きずつけている。↗

  Pollution is damaging our earth.
• 公害こうがいJLPT N2approx.Common
  nounPollution viewed as a public hazard: environmental contamination from factories, traffic, and the like that harms society. It fits 'contamination' only in that public-nuisance sense, not for the contamination of a specific substance or object.
  この地域ちいきに公害こうがいはない。↗

  This district is free from environmental pollution.
• 汚濁おだくCommon
  noun, suru verb, intransitive verbDescribes the state of being polluted or fouled, especially of water; it also means moral corruption or graft. For 'contamination' it is narrow — the fouled condition of water rather than contamination in general.

Use 汚染 as the default for contamination of the environment, food, or water; choose 公害 when pollution is framed as a public hazard affecting society; 汚濁 describes the fouled state of water, or moral corruption.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 汚染おせんpollution
• 公害こうがいpollution
• 汚濁おだくpollution
• コンタミネーションcontamination
• コンタミcontamination
• 異物混入いぶつこんにゅうcontamination (esp. foreign bodies in food)
• くすみdullness (esp. of the skin)
• 混交こんこうcontamination