1. （尤指有毒化学品造成的）污染
    Pollution is the process of polluting water, air, or land, especially with poisonous chemicals.

    e.g. The fine was for the company's pollution of the air near its plants...
           罚款是因该公司对厂房周边空气造成了污染。
    e.g. Recycling also helps control environmental pollution by reducing the need for waste dumps.
           对废弃物的回收利用能够减少对垃圾场的需求，从而也有助于控制环境污染。

2. 污染物
    Pollution is poisonous or dirty substances that are polluting the water, air, or land somewhere.

    e.g. The level of pollution in the river was falling.
           这条河中的污染物水平在下降。