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.
Metals released into the atmosphere from human activities pose a significant risk to ecosystems and human health. Small airborne particles with a diameter of less than 10 microns can be inhaled and then absorbed into the alveolar tissue of the lungs, resulting in damage.