Definition: Sibilance is a sound characterized by pronouncing words with the letter 's'. In audio reproduction the letter 's' should sound clear and distinct, not smeared or distorted as in 'sh'.
High air pollution levels can cause immediate health problems including: Aggravated cardiovascular and respiratory illness; Added stress to heart and lungs, which must work harder to supply the body with oxygen; Damaged cells in the respiratory system
Air pollution could be in the form of the emission of harmful chemical gases (e.g. carbon monoxide) or particulates (e.g. soot) in to the air. Air pollution could also be in the form of disturbances to the normal composition of the air such that there is an undesired effect on the environment or living things.he main types of pollution gases in the air are carbon dioxide, carbon monoxide, methane, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides. Read related articles on air pollution facts: 1  air pollution statistics. 2  car pollution facts.