(a) Using specific examples, describe any three causes of air pollution (b) Outline three major effects of air pollution (c) Suggest any three ways of contr...

Answer Details

(a) Three causes of air pollution (with examples)

1. Burning of fossil fuels: factories, power stations and motor vehicles burning coal, petrol and diesel release smoke, carbon monoxide, sulphur dioxide and lead into the air (e.g. traffic fumes in Lagos).
2. Industrial and mining processes: refineries, cement works and smelters give off dust, fumes and toxic gases (e.g. gas flaring in the Niger Delta oilfields).
3. Bush burning and burning of refuse: clearing farmland by fire and open burning of waste release smoke and soot into the atmosphere. (Others: volcanic eruptions and use of aerosols/CFCs.)

(b) Three major effects of air pollution

1. Health problems in man: respiratory diseases, bronchitis, lung cancer and eye irritation.
2. Acid rain: sulphur and nitrogen gases dissolve in rain to form acids that damage crops, forests, buildings and aquatic life.
3. Global warming and ozone-layer depletion: greenhouse gases raise world temperatures, while CFCs thin the ozone layer; smog also reduces visibility and harms plants.

(c) Three ways of controlling air pollution

1. Fit filters/scrubbers and catalytic converters to factory chimneys and vehicle exhausts to trap or reduce harmful gases and smoke.
2. Use cleaner energy and fuels (gas, solar, hydro-electric power, unleaded/low-sulphur fuel) instead of dirty coal and heavy oil.
3. Legislation and public education: enact and enforce anti-pollution laws, ban indiscriminate bush and refuse burning, and encourage tree planting to absorb carbon dioxide. (Also site industries away from residential areas.)