Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (not all languages do) between translating (a written text) and interpreting (oral or sign-language communication between users of different languages); under this distinction, translation can begin only after the appearance of writing within a language community.
Poor air quality is a major health risk, causing lung diseases, cardiovascular diseases, and cancer. Air pollution also impacts the environment, affecting the quality of fresh water, soil, and ecosystems.