Frequency: The word is one of the 3000 most common words in English.
1.
Pollution is the process of polluting water, air, or land, especially with poisonous chemicals.
The fine was for the company’s ~ of the air near its plants...
Recycling also helps control environmental ~ by reducing the need for waste dumps.
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2.
Pollution is poisonous or dirty substances that are polluting the water, air, or land somewhere.
The level of ~ in the river was falling.
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