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
A list of the human causes of air pollution includes vehicles, domestic smoke and heating, aircraft pollution, outdoor fires, and incineration of waste. To reduce the problems of air pollution, people should be more aware of their actions in these areas. 1  Human Activity: An overview of how human activity affects air pollution. 2  Air Toxics: A look at mercury and other air toxic emissions associated with production of electricity.