# pollutant

/pəˈɫutənt/ (US) · /pəlˈuːtənt/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/pollutant
Updated: 2026-10-12

## Definition

a substance that makes the air, water, or soil dirty and unsafe. You usually hear this word when talking about chemicals or waste that harm nature.

For teachers: a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. Often refers to chemical waste, noise, or heat that contaminates natural systems.

## Examples

- The factory released a dangerous pollutant into the nearby river.
- Environmental scientists are monitoring the levels of every major pollutant in the city's air to ensure they meet safety standards.
- While some substances occur naturally, they are classified as a pollutant when their concentration reaches levels that disrupt the ecological balance or pose a significant risk to human health.

## Pitfalls

- Not "The smoke is a pollution." but "The smoke is a pollutant." — Learners often confuse the general process (pollution) with the specific substance causing it (pollutant).

## Usage notes

- Commonly modified by adjectives like 'environmental', 'air', or 'industrial'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.