Question

Mention chief pollutants and their harmful effects.

Answer 1

1. Benzopyrene: A carcinogenic hydrocarbon mainly from motor vehicle emissions and incomplete combustion; causes death due to cancer.
2. Carbon Monoxide (CO): Produced by incomplete combustion of fuels; binds with blood hemoglobin reducing oxygen carriage, leading to asphyxiation, heart and brain damage, weakness, fatigue, and headaches.
3. Oxides of Nitrogen (NOx): Emitted from automobiles and industries; causes irritation to eyes, reduces oxygen-carrying capacity of blood, diminishes pulmonary function, causes edema of respiratory tract, and damages lungs and heart.
4. Oxides of Sulphur (SOx): Sulphur dioxide irritates eyes and respiratory tract, causing swelling and increased mucus secretion; leads to chronic bronchitis, pulmonary fibrosis, asthma, and emphysema. SO₂ converts to sulphuric acid in moist air causing acid rain and respiratory diseases.
5. Particulate Matter: Includes smoke, dust, metal particles such as cadmium, lead, mercury, and asbestos fibers; causes irritation, decreased lung function, stress on heart, respiratory diseases, cancer, tuberculosis, and occupational diseases like byssinosis.
6. Photochemical Oxidants (e.g., Ozone): Formed by reactions between NOx and hydrocarbons in sunlight; causes sore eyes, coughing, respiratory distress, decrease in lung function, emphysema, fibrosis, ageing of lungs, and heart failure.
7. Tobacco Smoke: Causes cancer and respiratory illnesses.