Question

Which one of the following is not an air pollutant?
(A) Sulphur dioxide
(B) Phosphates
(C) Carbon monoxide
(D) Hydrocarbons.

Answer 1

Hint: Air pollution is defined as the contamination of air due to presence of some undesirable particles. Air pollution is caused by some hydrocarbons, greenhouse gases like carbon dioxide, carbon monoxide. Sulphur dioxide when it gets mixed in rain it causes acid rain. Phosphates mix in water and lakes and cause water pollution. When phosphates are high in content it causes overgrowth of algae.

Complete answer:
Sulphur dioxide :- they mix with rain and cause acid rain. Acid rain damages the plants and other population which contaminates air. Thus it is a source of air pollution.
Phosphates:- they cause pollution of rivers and lakes and cause eutrophication of water bodies so it causes water pollution and not air pollution. Hence this option is correct.
Carbon monoxide :- it is a type of greenhouse gas and poisonous gas. When its content increases it causes air pollution. Hence this option is not correct.
Hydrocarbons :- methane gas released from cow dung or any other method causes air pollution. Hence this option is also incorrect.

Our required answer is B) phosphates.

Note: Phosphates enter the environment due to human activities. It can be released from laundry or any other actions. They mix up in lakes and rivers and cause their pollution. So they cause water pollution and not air pollution. In water they cause eutrophication and also cause overgrowth of algae which causes death of other organisms in water.