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
Environmental tobacco smoke is a contributor of air pollution particles. These fine particles are a risk factor for chronic lung disease which can be debilitating and sometimes fatal. They can lead to conditions such as asthma, bronchitis, and emphysema, and are also a risk for lung cancer, write the researchers. The test was conducted in the small, northern Italian mountain town of Chiavenna, which has unusually low outdoor levels of air pollution.