Causes and consequences of water pollution

Water pollution, or water pollution, is the alteration of the composition of water or its natural state. This alteration is caused by harmful agents that make the water unsuitable for consumption or use.

Causes of the contamination of the water

The causes of water pollution can be of natural origin, due to the presence of certain elements in the soil and atmosphere. But the most common thing is that humans are responsible for the pollution of the aquatic environment.

Discharge of polluting substances

Most waste reaches water sources through human activity. We can contaminate water by pouring different substances into it, such as plastic, pesticides, viruses, mercury, excrement or oil. Below we explain each one.

1. Plastic cup on the seashore. 2. Oil stain in water. 3. Explosion of an oil platform. 4. Nuclear waste containers under the sea.

Plastics, detergents and oils. Plastics from fishing and coastal activities that release toxic substances can be ingested and cause physical damage to marine species that are trapped in them. While the detergents and oils that come from wastewater, both domestic and industrial, that are evacuated into river beds, cause a decrease in the oxygen in the water.

Organic waste and nutrients. They come from urban sewage and livestock farms. Organic matter encourages the growth of bacteria that consume oxygen from the water and can transmit diseases. Agricultural pesticides and fertilizers leach through crops and reach river basins, where they cause excessive growth of organisms such as some types of algae.

Microbiological contamination. It is the presence of pathogenic microorganisms in water. Viruses, bacteria and parasites, which arrive through the organic remains of infected living beings and can cause poisoning and diseases.

Heavy metals and nuclear waste. Heavy metals, such as mercury present in the Earth’s crust, leach into the water as it passes over certain surfaces. However, the majority of heavy metals found in river sources come from industrial and mining activities. Nuclear waste, on the other hand, is caused by illegal dumping, accidents and leaks at nuclear plants, in addition to the water used to cool the power plants’ reactors, which also ends up in rivers and seas.

Chemical substances and drugs. They are mainly antibiotics used in treatments for animals, crops and humans, which reach the water through excrement and waste.

Oil and hydrocarbons. Oil reaches the environment through leaks and accidents on oil platforms or vessels. It is highly polluting because it can remain on the surface of the water, preventing the entry of light and oxygenation. Its adherence to the skin and fur of animals affects their body temperature, and can also cause respiratory problems and poisoning.


Arid and fertile land. Destruction of a forest with industrial machinery. Overflowing river.

Deforestation is the destruction of forests and forests by forest fires or at the hands of humans, who use the land to carry out construction or industrial activities.

When the flora disappears, soil hydration levels are destabilized. The vegetation cover serves to prevent rivers from overflowing and rains from washing away soil particles, sediments that reach the rivers and degrade the quality of their water.

Temperature increase

The increase in water temperature causes a decrease in oxygen that puts the life of the organisms that live in it at risk.

In addition to global warming, there are other factors that increase the temperature of water masses. For example, the water used in cooling processes in industrial plants can modify the temperature of the rivers and reservoirs where they are discharged.

Transportation systems

Remains of a shipwreck. Boat approaching a whale.

Maritime transport can suffer fuel leaks, discharge toxic substances and waste into the sea. Waste and garbage from recreational boats are the main pollutants, without forgetting the noise pollution caused by the noise and vibration of the engines.

Natural water cycle

Water is a determining factor for the climate because the temperature on the planet is regulated through the water cycle. This process significantly influences water and atmospheric pollution.

When contaminated water evaporates, harmful substances enter the atmosphere and return in the form of rain, droplets of contaminated water that end up in the hydrosphere.

Consequences of water pollution

Polluted water deteriorates life and the environment as it flows; Next we will see how it affects development and the environment.

Health effects

Raw water coming out of a tap. Man drinking from a fountain.

Water is responsible for transporting nutrients from the soil to plants and inside living organisms. Its pollution causes diseases in animals, plants and humans.

Ingesting contaminated water or food can cause infections, poisoning and transmit parasites and diseases, such as diarrhea, yellow fever, hepatitis or cholera.

Impact on biodiversity

Fish trapped in a plastic glove. Sea lion tangled in a rope. Duck swimming through garbage.

Water is the basic resource that sustains life in the planet’s natural ecosystems. Its pollution causes damage to aquatic habitats and marine ecosystems, many animals lose their lives due to asphyxiation or poisoning by ingesting toxic substances and waste.

On the other hand, maritime transport can cause serious injuries when impacting marine animals and noise pollution hinders the communication of some species such as the dolphin.


Water surfaces infested with algae

It is an excessive load of nutrients in the water, which come from fertilizers, pesticides and detergents used for agricultural and industrial activities.

These nutrients favor the growth of algae and other organisms that consume the oxygen dissolved in the water, putting the lives of other species at risk.

Effects on the economy

Remains of different marine animals. Beach polluted with garbage.

Pollution interferes with the economic development of countries without means to purify water. The lack of conditions to preserve hygiene and health poses a high risk of mortality. In the same way, the scarcity of drinking water affects the production of food that meets the necessary sanitary conditions.

The contamination of fish, shellfish and food extracted from the sea prevents them from being used for commerce and causes great losses to the fishing industry. Tourism also declines on coasts infected by garbage dumps, oil spills or the excessive presence of algae.

Learn more about:

How to cite: “Causes and consequences of water pollution.” In: Available in: https:///causas-y-consecuencias-de-la-contaminacion-del-agua/ Consulted: