First Term Lesson Note for Week Two
Class : Primary Five
Subject : Basic Science
Topic : Pollution (Meaning and types)
Duration : 40 Minutes
Period : Single Period
Reference Book :
Basic Science and Technology for Primary Schools, Book 5.
Lagos State Unified schemes of work for Upper Primary School, Primary 4 – 6.
Online Resources
Instructional Material : Chart showing the meaning and types of pollution
Learning Objectives : By the end of the lesson learners will be able to :
i. Define pollution and list some agents of pollution.
ii. List common causes of pollution
iii. 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
Content :
Pollution can be defined as the release of harmful substances to the environment.
Substances that are released and harmful to our health and environment at large are called pollutants. Examples of pollutants are :
Meaning of Pollution
Our environment is our surroundings. It consists of the living (biotic) and non-living (a biotic) elements of our surroundings. The three major components of the environment are physical, biological and socio-economic.
The environment contains every essential element which man needs to survive. At the same time, the environment contains potential hazards which pose threats to the existence of man and other living organisms. These hazardous elements are either natural or man-made.
Pollution means making the environment unsafe for plants and animals. When the air, water and land get contaminated” they become serious health hazards and security threats to man and other living organisms.
Pollutants
Pollutants are substances that are capable of contaminating the environment. Pollutants can be in their solid, liquid and gaseous forms
2) Types and Causes of Pollution
Pollution may affect the soil, rivers, seas or the atmosphere. This means that there are many forms or types of pollution with different causes.
Types of Pollution
There are three major types of pollution, namely:
Land pollution
Water pollution and
Atmospheric or air pollution
AIR POLLUTION DUST
When we sweep the floor in our homes or compounds without first sprinkling
water on the floor, dust rises into the air. Tractors also raise dust when they are used to cultivate farmland in dry weather. Lorries and cars raise dust as they move on roads, especially untarred roads.
Carbon dioxide
Carbon dioxide is passed into the air whenever anything burns in air. Vehicles that use petrol or diesel add a lot of carbon dioxide to the air. The flaring of natural gas also causes the pollution of air with carbon dioxide.
Carbon monoxide
Carbon monoxide is produced when fuel burns in an insufficient amount of atmospheric oxygen. There are reports of people who have died as a result of carbon monoxide poisoning when they operated their electric generators in homes with closed doors and windows.
Harmful effects of air pollution
Smoke makes us cough and causes tears to flow from our eyes. In Nigeria, packets of cigarettes carry this notice: ‘The Federal Ministry of Health warns that smokers are liable to die young’.
Carbon dioxide forms 0.3% of the atmosphere. An increase in atmospheric carbon dioxide beyond this level causes the earth to become warmer than it should be. This has bad effects on the weather, e.g. high temperatures, rising of the sea level and strong storms.
Carbon monoxide is poisonous to human beings. Inhaling much carbon monoxide causes death.
Inhaling particles of wood, clay, chalk and other materials leads to disorders in the human breathing system.
Control of air pollution
Air pollution can be controlled in these four major ways:
Provision of good ventilation in homes by having an adequate number of windows.
Sprinkling of water on the floor or land before sweeping it.
Keeping engines in good repair and well-serviced form.
Avoiding operating electric generators in closed rooms.