Name one source and one harmful effect of each of the following air pollutants:
(a) Sulphur dioxide
(b) Nitrogen oxides
(c) Carbon monoxide
(d) Chlorofluorocarbons (CFCs)

(a) The source of Sulphur dioxide in the air is the fossil fuels combustion in power plants and other industries. It can also be produced by motor vehicles emissions.

Sulphur dioxide is a very harmful pollutant when present in the atmosphere. It can cause respiratory problems, including permanent lung damage.

(b) The source of nitrogen dioxide in the air is produced by motor vehicles.

Nitrogen dioxide is a very harmful pollutant because it combines with other air pollutants and fog to form smog. The smog is responsible for causing breathing difficulties such as asthma, cough and wheezing in children.

(c) The source of carbon monoxide in the air is the incomplete burning of fuels such as petrol and diesel.

Carbon monoxide is a very poisonous gas that reduces the oxygen carrying capacity of the blood.

(d) Chlorofluorocarbons are used in refrigerators, air conditioners and aerosol sprays.

Chlorofluorocarbons are responsible to deplete the ozone layer in the atmosphere. The ozone layer protects us from the harmful ultraviolet rays of the sun. This results in an increase of ultraviolet radiations at ground level which leads to an increased risk of skin cancer.