pollutant

American  

[puh-loot-nt] / pəˈlut nt /

noun

1. something that pollutes.

2. any substance, as certain chemicals or waste products, that renders the air, soil, water, or other natural resource harmful or unsuitable for a specific purpose.

---

pollutant British  

/ pəˈluːtənt /

noun

1. a substance that pollutes, esp a chemical or similar substance that is produced as a waste product of an industrial process

---

pollutant Scientific  

/ pə-lo̅o̅t′nt /

1. A substance or condition that contaminates air, water, or soil. Pollutants can be artificial substances, such as pesticides and PCBs, or naturally occurring substances, such as oil or carbon dioxide, that occur in harmful concentrations in a given environment. Heat transmitted to natural waterways through warm-water discharge from power plants and uncontained radioactivity from nuclear wastes are also considered pollutants.

---

Other Word Forms

• nonpollutant adjective

Etymology

Origin of pollutant

First recorded in 1890–95; pollute + -ant

Explanation

Any substance that makes the environment dirty or contaminated is a pollutant. Soot is an example of an air pollutant, and chemical pollutants can make their way into the water supply. Trash that doesn't quickly biodegrade is one kind of pollutant—think of plastic bags floating around in the ocean. Chemicals that find their way into the air we breathe and the water we drink are another kind of pollutant. Pollutant comes from pollution, from the Late Latin pollutionem, "defilement," and its root polluere, "to soil or defile."

Example Sentences

"We're starting to learn more about this toxic, organic pollutant that we know is out there, and which we need to understand better."

From Science Daily • Apr. 11, 2026

Coal is a top contributor to planet-warming greenhouse gases, and also a powerful air pollutant that is harmful for human health.

From Barron's • Mar. 24, 2026

Dissenting in Massachusetts, Justice Antonin Scalia wrote that from the court’s reasoning, “it follows that everything airborne, from Frisbees to flatulence, qualifies as an ‘air pollutant.’

From The Wall Street Journal • Feb. 18, 2026

Environmental Protection Agency is through the Clean Air Act, which does regulate sulfur dioxide as a pollutant and as a contributor to acid rain.

From Salon • Dec. 12, 2024

It is a bit of a chemical oddity in that at ground level it is a pollutant, while way up in the stratosphere it is beneficial, since it soaks up dangerous ultraviolet radiation.

From "A Short History of Nearly Everything" by Bill Bryson

Related Words

• poison
• pollution
• toxic waste
• toxin