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What are the effects of water pollution?

December 10, 2019
topic:Ocean Pollution
tags:#water, #pollution, #environment, #climate change
by:Ama Lorenz
Water pollution is a serious environmental problem that not only affects human health, but also wildlife and our environment as a whole. From algal blooms to contaminated drinking water, the effects of water pollution can be devastating and wide-ranging.

Water covers over 70% of the earth’s surface. It is also the most basic requirement for survival. It also supports aquatic life and other ecosystems. Consequently, understanding water pollution and its effects are essential.

What is water pollution?

It is the contamination of water bodies such as oceans, seas, lakes, rivers, groundwater, and aquifers by pollutants. The contaminants can end up in the water by the direct or indirect application. It is the second most prevalent type of environmental pollution, after air pollution. Below is an insight into the different types of water pollution and its effects.

Types of water pollution

Water contamination is categorised based on the source or the nature of the water body it affects. Some of the most common pollution types are:

Surface water pollution

Surface water includes water that is found naturally on the earth’s surface. They include lagoons, rivers, oceans, and lakes. Contamination of such water features results from the dissolving or mixing of the water with pollutants. It can be accidental, such as oil spills in the ocean or intentional, like industries eliminating their wastes into rivers or sea.

Groundwater pollution

It occurs when the hazardous chemicals and particles applied on the surface by humans seep into the ground by rainwater. The contaminants pollute underground water features such as underground rivers and waterbeds. As a result, wells and boreholes might become contaminated. The most common cause of this type of pollution is the use of pesticides and fertiliser on farms.

Chemical pollution

Chemicals are the most common type of water contaminants. They affect both surface and underground water bodies. Industries and farming activities are the leading cause.

Solvents and metals used in industries can pollute rivers and lakes. Weed, insects, and fungi control in farms using pesticides is the other cause of soil contamination. Chemical contamination also results from petroleum spills.

Nutrients pollution

Even though nutrients are essential for plant and aquatic life, an excess of it is dangerous. Wastewater and fertilisers have a high content of nutrients required for plant growth. Consequently, they cause rapid and uncontrolled growth of vegetation and algae on the water surface when they end up in the water.

It leads to clogging of water filters and contamination of drinking water. It also uses up all the oxygen leading to the destruction of marine life.


Eutrophication is a process that occurs when an abundance of plant nutrients, such as phosphorus and nitrogen, accumulate in waterways. This can cause algal blooms, which are dense growths of algae that block sunlight from entering the water and deplete oxygen from the water, leading to fish kills. Although some algal blooms can be beneficial for ecosystems, they can also be toxic and detrimental to the environment.

Oxygen depletion pollution

Aquatic microorganisms thrive on biodegradable substances. When many of these materials get into the water, the number of microorganisms increases. They use up all the oxygen in the water. The depletion of oxygen leads to the death of aerobic microorganisms but promotes the thriving of anaerobic organisms.

Certain anaerobic microorganisms contaminate the water by producing toxins such as sulphides and ammonia. All these are harmful to humans and aquatic life.

Microbiological pollution

It is a natural type of contamination of water, as it results from natural existing microorganisms such as protozoa, viruses, and bacteria. Water containing some of these microorganisms can cause diseases such as cholera and bilharzia. The effects of microbiological pollution are common in areas where people drink untreated water.

Suspended matter

Some contaminants do not dissolve in water and are too large to mix with water molecules. They include can, straws, and other large objects. When suspended, they form a layer on the surface of the water, preventing oxygen penetration leading to oxygen depletion pollution.

Some of the particulate matter may settle at the bottom of the lake, ocean, or river, affecting the life on the floor of the river, lake, or ocean. In some cases, the material can comprise of harmful toxins.

Effects of water pollution

Pollution of water affects both humans and aquatic life. Most water sources close to cities and urban centres are polluted by garbage and dumping of chemicals, legally or illegally. Below are some of the common as well as adverse effects of polluting water bodies.

Effects on human beings

Life is a cycle, and humanity’s irresponsible behaviour often comes back to haunt it. Adding contaminants to water bodies has affected the human family in several ways. According to a 2017 WHO report, 2.1 billion people do not have access to safe water. In 2019, it stated that 785 million people lack access to essential drinking water.

One of the main effects of this is diseases. World Health Organisation notes that there are about 120,000 cholera-related deaths annually. Also, the Fukushima tragedy, for example, increased the prevalence of thyroid cancer in exposed infants by 70%.

Death of aquatic life

Animals and plants that depend on water for life are the most affected by polluted water. Statistics from the Centre for Biological Diversity on the effects of the Deep Horizon spill provides a useful glimpse of the impact of pollution on aquatic life. In the report, the 2010 spill on the Gulf of Mexico harmed over 82,000 birds, 25,900 marine animals, 6165 sea turtles, and an unknown number of fish and invertebrates.

Food chain disruption

Pollution disrupts the food chain by moving the toxins from one level in the chain to higher levels. In some cases, pollution can wipe out an entire part of the food chain. Such affect the other organisms by either causing excessive growth, in case the predator dies or death (if it wipes out the prey).

Destruction of ecosystems

The introduction or elimination of certain microorganisms distorts the ecosystem. Nutrient pollution, for example, leads to an increase in algae, which depletes the water of oxygen, thereby leading to the death of fish and other aquatic life.

Economic effects

Managing and restoring polluted water bodies is expensive. For example, Japan declared in 2019 that it is running out of space to contain the contaminated water after the Fukushima disaster. It currently has over a million tons of contaminated water stored in tanks. Research shows that it will cost at least $660 billion to clean up the effects of the disaster.

In normal conditions, it costs more to purify drinking water, not to mention the health cost of treating diseases resulting from contaminated water.


Water is an essential natural resource for the life of all living things. Any irresponsible behaviour in the part of humanity affects all the other beneficiaries. Consequently, there is a need to protect water bodies from deliberate pollution.

Article written by:
WhatsApp Image 2022-10-25 at 20.38.38
Ama Lorenz
Co-founder, Editor-in-Chief, Author
Embed from Getty Images
It is the second most prevalent type of environmental pollution, after air pollution.
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Chemicals are the most common type of water contaminants.
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Any irresponsible behaviour in the part of humanity affects all the other beneficiaries. Consequently, there is a need to protect water bodies from deliberate pollution.
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