Lesson Video: Water Pollution | Nagwa Lesson Video: Water Pollution | Nagwa

Lesson Video: Water Pollution Science • Second Year of Preparatory School

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In this video, we will learn how to describe different types of water pollution and the precautions which can be taken to prevent it.

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Video Transcript

In this video, we will learn how to describe different types of water pollution and the precautions that can be taken to prevent it.

Water is an essential resource on our planet. It is used for drinking, bathing, cooking, and in industry and agriculture. We obtain this water from sources such as wells, rivers, seas, oceans, and rainfall. Sources of water must be kept free from pollution to maintain a sustainable supply of usable water in the future.

Environmental pollutants can be divided into two categories: natural pollutants and artificial pollutants. Natural pollutants are pollutants that contaminate the environment and are generated by natural disasters or phenomena. Examples of this include volcanic eruptions, the death and decay of wild animals, and lightning strikes.

When a volcano erupts, vast quantities of dust and ash can be injected into the atmosphere, polluting the air. Lava flows can accompany volcanic eruptions and may start fires. As trees and vegetation burn, carbon dioxide is generated through combustion, increasing greenhouse gas concentrations in the atmosphere.

Lightning also causes pollution by generating gas. The high energy of a lightning bolt can cause a chemical reaction between nitrogen and oxygen molecules in the air, generating nitrogen dioxide and ozone.

When animals die and begin to decompose, methane gas can be generated, which is a greenhouse gas. And if an animal dies near a water source, this water can become contaminated as the carcass rots away. These natural phenomena either don’t occur frequently or do not generate large quantities of pollutants.

Artificial pollutants are pollutants that contaminate the environment and are generated by human activities. In this video, we will focus on artificial pollutants which can contaminate our water sources. There are four types of artificial water pollutants. They are biological, chemical, thermal, and radiant.

Biological water pollution is primarily caused by the disposal of human waste and large quantities of animal waste from herds of livestock in water sources such as rivers and lakes. Human and animal waste contain pathogens which spread disease upon entering the water supply. Diseases caused by this sort of pollution include bilharzia, which is also known as snail fever, typhoid, and hepatitis.

Chemical pollution in waterways primarily originates from factories. Some factories discharge harmful chemical waste directly into water sources. These chemical wastes increase the concentration of harmful substances, like mercury or lead, in the water. These elements can be absorbed by plankton, algae, and simple organisms. These plants and simple organisms are eaten by small animals, such as insects and small fish. The small fish and insects are then eaten by birds and large fish. The birds and large fish are then eaten by larger predators, such as humans. So we can see how this kind of pollution works its way through the food chain. Over time, eating fish containing high quantities of lead can result in damage to the brain and central nervous system. Mercury enters the food chain in the same way. But also mercury can be consumed by humans more directly via drinking water. High levels of mercury in drinking water can lead to blindness.

Thermal pollution is used to describe the artificial rise or fall in the temperature of a water source. For example, water can be used as a coolant in nuclear power stations and other industrial sites. Cold water is taken in by the power plant from the environment. It is cycled through the plant to keep the plant cool. This causes the water to increase in temperature. Thus, when it is released back into the environment, it is artificially warm. Oxygen is less soluble in warm water. Thus, the amount of dissolved oxygen in a water source starts to decrease as the water temperature rises. The lack of oxygen can result in the death of marine organisms.

Nuclear reactors can also cause radiant pollution. Radiant pollution results from the leakage of radioactive substances from nuclear reactors and the dumping of atomic waste into seas and oceans. For example, in 2011, an earthquake and tsunami caused the nuclear meltdown of a nuclear power plant, causing large quantities of water to be polluted with radioactive isotopes.

Now that we know the different types of artificial water pollution, we will look at how to protect water sources and reduce water pollution. Water pollution can be reduced by ceasing to dump human and animal sewage into water sources and by prohibiting factories from discharging harmful waste into water sources. It would also help to educate the population about environmental issues related to water safety and protection, as well as using bottles free from BPA and phthalates, as these chemicals have been associated with poor health and disease.

We can also use water purification stations and systematic analysis to produce and monitor drinking water and periodically disinfect water storage tanks, commonly found on top of buildings. Finally, we can develop programs to monitor and clear up dead animals that may be contaminating water sources.

Now that we have learned about different types of water pollution and the precautions taken to prevent it, let’s take a look at some example questions.

Which of the following statements best describes the term “artificial pollutants”? (A) Artificial pollutants are created to replace natural pollutants. (B) Artificial pollutants are not real pollutants. (C) Artificial pollutants are created when living organisms die. (D) Artificial pollutants are the result of human activities. Or (E) artificial pollutants are superficial and easily treated.

The word “artificial” has many meanings, but generally it means something that is not natural or not naturally occurring. For example, a prosthetic limb, which is produced by human beings, rather than occurring naturally, is known as an artificial limb. Thus, in the context of pollution, artificial pollution is pollution generated through human activities. An example of artificial pollution would be the leaking of nuclear waste. Therefore, the statement which best describes the term “artificial pollutants” is answer choice (D). Artificial pollutants are the result of human activities.

Which of the following occurrences that create pollution is not considered a natural pollutant? (A) Volcanoes, (B) decaying of living organisms, (C) farming and agriculture, (D) lightning, or (E) earthquakes.

Natural pollutants are pollutants that contaminate the environment and are generated by natural disasters or phenomena. There are two main types of pollutant, one being natural, the other being artificial. Artificial pollutants are pollutants that contaminate the environment and are generated by human activities. We can classify volcanoes, decaying of living organisms, lightning, and earthquakes as natural phenomena. These occurrences are therefore likely to be sources of natural pollutants. Farming and agriculture, on the other hand, only exists because of human activities. Therefore, it seems as though farming and agriculture is an artificial pollutant.

Thus, the answer to the question “Which of the following occurrences that create pollution is not considered a natural pollutant?” is (C), farming and agriculture.

Why is the chemical pollutant mercury, found in varying concentrations in certain areas of seawater, considered dangerous to human health? (A) Mercury changes the temperature of the water, killing smaller fish. (B) Seawater is used to produce drinking water, but mercury cannot be removed. (C) Mercury can damage the holes of boats and ships in the area, potentially sinking the ships. (D) Mercury is corrosive and can burn the skin of swimmers in the area. Or (E) mercury builds up in the food chain and collects in large concentrations in fish.

Chemical pollutants cause chemical pollution, which may come from factories and industries not carefully disposing of waste or disposing of waste directly into water sources. A well-known example of chemical pollution is the buildup of mercury. When mercury enters a water source, it is initially absorbed by simple organisms, such as plankton. The plankton is fed upon by slightly larger fish, which in turn are eaten by even larger fish. In this way, large amounts of mercury can build up in the food chain. Eventually, humans might eat fish containing large amounts of mercury.

For certain animals and humans, frequently eating fish with large amounts of mercury can cause negative health outcomes. Therefore, the chemical pollutant mercury is considered dangerous to human health as mercury builds up in the food chain and collects in large concentrations in fish, or answer choice (E).

Let us summarize what we have learned about water pollution and the precautions that we can take to prevent it. Water is an essential commodity on Earth. And it is used by individuals as well as in manufacturing and agriculture. There are two key types of environmental pollutants: natural and artificial. Natural pollutants are the result of natural disasters or events, such as volcanic eruptions, whereas artificial pollutants are produced as a result of human activity.

The four types of artificial water pollution are biological, chemical, thermal, and radiant. Biological water pollution is most often caused by human and animal waste disposal in rivers and lakes. Factory waste is the main cause of chemical pollution. Thermal pollution is a form of water pollution that occurs when a water supply’s temperature is raised or lowered artificially, for example, by using water as a coolant. Radiation pollution is the term used for the increase in radiation levels caused by human activities, for example, from nuclear waste.

Lastly, there are many ways in which we can effectively protect our water supplies from contamination. For example, we can prohibit factories from discharging harmful waste into water sources. We can also periodically disinfect water storage tanks commonly found on top of buildings.

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