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 can irritate the eyes, throat and lungs. Burning eyes, cough and chest tightness are common with exposure to high levels of air pollution. People can react very differently to air pollution. Some people may notice chest tightness or cough, while others may not notice any effects.