Back to: Jss1 Basic Science (BST)
Topic: Environmental Pollution
WEEK: 5 & 6
Pollution is the introduction of harmful substances into the environment that can adversely affect living things and the natural environment.
Pollution is also the introduction of contaminants into the environment that cause harm or discomfort to humans or other living organisms or that damage the environment” which can come “in the form of chemical substances or energy such as noise, heat, or
The harmful substances that can cause pollution are called pollutants.
Types of Pollution
The types of pollution are air pollution, water pollution, soil pollution, and noise pollution.
Water pollution is a type of pollution that involves the contamination of different bodies of water. A variety of aquatic creatures rely on these bodies of water and their naturally nutritious features to survive. The contamination of water bodies like lakes, oceans, rivers, and seas is also called “water pollution.” Water pollution adversely affects the living organisms living in these bodies of water. Water pollutants include insecticides and herbicides, food processing waste, pollutants from livestock operations, volatile organic compounds (VOCs), heavy metals, chemical waste, and others.
The major causes of water pollution are:
- Sewage and wastewater: Pathogens, harmful microorganisms, are introduced into bodies of water when the sewage and wastewater used by every household are deposited in these bodies of water.
- Fertilizers, herbicides, and other organic pollutants: Chemicals like fertilisers, herbicides, and pesticides used by farmers to increase the yield of crops can be washed into water bodies by runoff.
- Global warming: Depletion of the ozone layer by oxides of carbon and nitrogen causes global warming. Global warming can cause the death of marine organisms, thereby polluting the water.
- Oil spillage: Oil spills on bodies of water caused by truck tankers, pipelines, and underground storage tanks can pollute them. Petroleum products are poisonous to aquatic animals, and spilt oil can damage the feathers of birds and the fur of animals.
- Refuse dumped into gutters can pollute water bodies. This is because when these refuse items are washed into bodies of water, they pollute them, thereby causing the death of the aquatic organisms in the water.
- When detergents are used to wash clothes near lakes and rivers, a condition called “eutrophication” happens. This keeps sunlight from getting in and lowers the amount of oxygen in the water, making the area unlivable.
- Some natural disasters, like flash floods and hurricanes, mix water with dangerous things on the ground.
Water pollution control
To stop water pollution, people can do things like be more careful about dumping harmful substances into the water. Water treatment plants are being built with new ways to clean up polluted water in order to fix the damage that has already been done. But some of the damage can always be fixed. Because water is so important to human survival, it is best to keep it from getting polluted. There are three main types of ways to stop water pollution: physical, chemical, and biological. For example, fine dirt and dead organisms that float in the water are types of water pollution. These things can be taken out of the water by either letting it sit still for a while, which lets the pollutants settle to the bottom, or by running the water through a filter. (The filter then catches the solid pollutants.) Pollutants can be removed from water by using chemical reactions. For example, when potassium aluminium sulphate (alum) and lime (calcium hydroxide) are added to water, a thick, sticky precipitate forms. When the precipitate starts to settle, it traps solid particles, dead bacteria, and other parts of dirty water and carries them with it.
Soil pollution occurs when dangerous chemicals, pathogens, or radioactive materials get into the soil in a certain area.
Causes of Soil Pollution
Some things that pollute the soil are:
- Most developing countries don’t know how to properly get rid of the trash, so they turn a piece of land into a dump. Contaminants in the trash can stop water from getting into the soil and change its ability to hold water.
- Nuclear waste that is thrown away in a way that is illegal and not based on science can pollute the soil and cause mutations.
- When toxic fumes from factories combine with rain, acid rain is formed. Acid rain makes the soil more acidic, which is bad for plants.
- Herbicides and pesticides are two kinds of chemicals that farmers sometimes use to kill unwanted plants and pests. Beneficial microorganisms and plants are killed during this process, leaving the soil sterile and dependent on fertilisers. This means that a lot of fertiliser is used, which makes more polluted water run off into bodies of water.
Solid pollutants are controlled.
Solid pollutants are things like refuse, sewage sludge, paper, plastic, and many other types of waste. One way to get rid of solid pollution is to just bury it in a dump or landfill. Composting them is another way to get rid of them. In this process, microorganisms turn some types of pollution into useful fertilizers. Last but not least, solid pollutants can also be burned.