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
2. Human Health : The decrease in quality of air leads to several respiratory problems including asthma or lung cancer. Chest pain, congestion, throat inflammation, cardiovascular disease, respiratory disease are some of diseases that can be causes by air pollution.