WEEK 3&4

SUBJECT: BASIC SCIENCE

TERM: 1ST TERM

CLASS: PRIMARY 5

TOPIC: TYPES OF POLLUTION

SUBTOPIC: CAUSES, EFFECT AND PREVENTION OF POLLUTION

WATER POLLUTION

Causes of water pollution

(i) Untreated sewage released into water bodies.

(ij) Dumping of human faeces, dead animals, etc. into water bodies.

(iii) Oil spillage i.e. leakages, from oil tanks and pipes, into streams, rivers etc. (iv) Industrial effluents (liquid waste from industries) released into water bodies.

Effects of Water Pollution

Harmful effects of water pollution

Polluted water is not good for domestic purposes. It is also not good for some industrial purposes. The reasons are as follows:

1. Soaps, detergents and various industrial or chemical waste are harmful to human health and to fish used as food by human beings.
2. Polluted water is unfit for drinking.

3. Water polluted by crude oil (petroleum) is unfit for swimming or other recreational activities.
4. Petroleum and industrial chemical waste, which kills fish or small water plants and animals that fish eat, negatively affects the fishing industry. In this way, water pollution has made many fishermen jobless.
5. Petroleum and other industrial chemical waste in water may enter farmlands near polluted rivers and make the soil unproductive.

Control of water pollution

The harmful effects of water pollution can be reduced by communities and industries through these measures:

1. Too much fertilizers should not be applied to farms.
2. Laundries should not empty water containing soap and detergent directly into streams and rivers.
3. Waste water containing oil and soap or detergent from homes should be directed into soakaway pits.
4. Leaking petroleum pipelines, tanks and ships should be repaired promptly.

LAND POLLUTION ������� �

Pollutants of the land include solid refuse, chemical waste from industries, faeces, and disused bodies of old vehicles and equipment.�

Harmful effects of land pollution

The pollution of land is harmful to man in many ways, some of which are as follows:

1. Abandoned refuse occupies land space and it is not pleasant to look at. It also creates a home for animals that carry disease- causing organisms, such as cockroaches and flies.
2. Houseflies visit faeces left in bushes and may later transfer germs (sticking to their bodies) to uncovered human food.
3. Bodies of old vehicles, refrigerators and engines may injure children playing in an area where these are abandoned.
4. Refuse dumped at roadsides may cause vehicle accidents.

Control of land pollution

1. People should use proper latrines or water closets in homes, offices, markets and other public places.
2. In each home, refuse should be put in dustbins, and carried to proper collection centres, from where they should be sent to proper disposal places.
3. Materials should be recycled, i.e. waste material should be used again and again, e.g. paper and bottles.

ASSESSMENT AND EVALUATION

1. Define pollution and list some agents of pollution.
2. List common causes of pollution
3. Discuss the role of human activities in the degradation of the environment iv) Identify the causes of pollution on land, water, and air v) Suggest ways of reducing pollution of the environment

WRAP-UP (CONCLUSION)

Teacher goes over the topic once again to enhance better understanding.

ASSIGNMENT

1. What is pollution?
2. Name six different types of pollutants.
3. Write short notes on different types of pollution.
4. What are the causes of pollution?
5. State the economic importance of pollution.
6. How can you control pollution?