The environment is the whole of our surrounding. It is made up of living and Non-living components. The non-living components consists of water, air, and land (soil). These three Non-living components are important for lives on earth.
Humans engage in daily activities that requires the use of water, air and land. These activities includes cooking, farming, washing, transportation, manufacturing, building and many others. These activities often lead to the production of some waste products, which are discharged directly or indirectly into the environment.
The discharge of waste substances into the environments in quantities that are harmful to human beings is called pollution. The waste substance which cause the pollution, are called pollutants. With technological advancement, human activities have increased greatly and pollution has become a major challenge to human survival. Unless we use our knowledge to control pollution and pollutants, our environment may become dangerous for human beings. Pollution may occur in water, air, soil.

Water pollution; Clean water is colorless, odourless and tasteless. If water loses all these qualities, then it’s no longer safe for drinking. If seawater or river water becomes unclean, it may become unsafe for the organisms that live in it. Imagine the sitting of a textile industry near a stream, which is the major source of water supply for your community. The washing of the coloring chemicals are allowed to flow into the stream daily. Soon the stream becomes colored and unsafe for the people to use.
The discharge of harmful waste substance into a body of water is described as water pollution. Water becomes polluted when it loses it’s natural qualities and becomes unsafe for living things. Polluted waters may contain materials that are poisonous to living things. However, boiling and filtration of water before use may destroy some of the poisonous substance.

Causes of Water Pollution;

Water pollution is caused by the discharge of waste substance into the body of water in amount that are harmful to organisms. The waste substance are generated from the activities of human beings at home, in the industries or farms. They could be discharged directly or indirectly into bodies of water. The waste substances generated from activities in the home are called domestic wastes. Those from industries and farms are called industrial wastes. There are many types of domestic and industrial wastes.

Polluted water site

1. Domestic waste substance includes the following;
Soap and detergents used in washing plates, clothes, cars and other materials may be allowed to flow back into the source of water supply in the community (such as streams).
2. Oils such as vegetable oil, kerosene, engine oil or even petrol from cars, which are spilled in the home or washed out from pots may be allowed to flow into the source of water supply.
3. Refuse dumped besides the river or stream in the community may decay and produce toxic materials, which may be washed by rain into the river/stream.
4. Dung from animals such as chicken, dog, left on land may decay and the poisonous materials in them are washed by rain into the rivers or streams around your home.
5. Human faeces sometimes contain eggs of intestine worms and other harmful micro-organisms. If human faeces are not properly disposed of, but left on the land in the bushes, rain water may wash the disease-causing organisms into nearby streams, which are sources of water for domestic use.

Water pollutants generated from industries may include the following:

1. Acids e.g. hydro-cyanic acid, which is present in the water squeezed out from cassava in the garri processing industry.
2. Soap and detergents are used in washing up some industrial equipment and the washing may be allowed to flow into nearby bodies of water.
3. Alcohol, which may be washed out from bottles in breweries.
4. Oils such as crude oil, Vegetable oil, Engine oil, petrol may spill from industries that produce and use them and may also be washed into streams and rivers by rain and floods.
5. Chemical compound such as lead sulphate, zinc sulphide, sulphuric acid (tetraoxosulphate VI) may be produced as industrial wastes from chemicals, battery or paint industries. Chemical compounds that pollute water may also come from the use of fertilizers and weed killers by farmers.


1. Reduce activity; Organism that depends on water may find it difficult to use polluted water, and the common effect is that aquatic organisms are poisoned by the pollutants.
2. Death of Organisms; Polluted water contains poisonous substances which may kill organisms such as fish.

Dead fishes in polluted water


3. Prevention of sporting activities; Sporting activities such as swimming and fishing may become difficult in polluted streams and river.
4. Health hazard; Quite a number of water-borne diseases come from water polluted by human faeces. Examples are typhoid, elephantiasis, skin rashes etc.
5. Adverse effects on economy; Water pollution can affect the economy or income of individuals, family and societies. For instance, fishing is a profitable human activity. If all rivers were polluted, fishermen would be out of business and without income.


The increase in water pollution has become a disturbing issue in most countries of the world. Humans are mostly affected by water pollution as we continue to lack safer water supply. People in the cities use more water than those in the rural communities. Also, city people generate pollutants in their houses and industries more than the rural people. However, whether you live in the city or rural area, there is need to take control measures against water pollution.
Control of water pollution would involve the control of the discharge of both domestic and industrial waste substances. Waste substances may be properly disposed of so that they do not enter nearby streams and rivers. Also, care should be taken to use only minimum amount of the products that generate key pollutants. For example, only minimum amount of detergents should be used at home and in industries in order to control the amount of detergents pollutants generated and discharged.


The table below shows the sources of water pollutants, effects and control:

Done studying? See all lessons in Basic Science/Technology

Take a quick test for this lesson

1. Water pollution may be controlled by (a) making a good suck-away pit (b) repair of leakages in our roofs (c) Sweeping our rooms regularly (d) Regular disposal of refuse
2. Define Water Pollution
3. Name six water pollutants
4. State five major causes of water pollution
5. Explain the effect of water pollution on:
(a) the environment
(b) human beings
(c) the economy
6. Write a full report of your visit to polluted water site, describing the causes, the effects of life in the community and most possible control measures.
Questions Answered correctly? Bravo!!

Stay connected to itsmyschoollibrary.com for more educational contents.