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 is both natural and human-based. Natural air pollution is caused by phenomenon such as volcanic eruption, wind erosion, decomposition and radioactive materials. Writing essay can only do as much in explaining each cause. Volcanic eruptions send sulfur dioxide, tons of ash, and soot into the air which mixes with water vapor to form acid rain.