Causes and consequences of water pollution

Water pollution, or water pollution, is the alteration of the composition of the water or its natural state. This alteration is caused by harmful agents that make the water unfit 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 the atmosphere. But the most common is that humans are responsible for the contamination of the aquatic environment.

Dumping of polluting substances

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

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 detergents and oils that come from wastewater, both domestic and industrial, which are discharged into river beds, cause a decrease in oxygen in the water.

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

Microbiological contamination. It is the presence of pathogenic microorganisms in the 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, seep into the water as it passes through certain surfaces. However, most of the 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 reactors of the plants, which also ends up in rivers and seas.

Chemical substances and drugs. They are mainly antibiotics used in treatment of 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 rigs 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.


Deforestation is the destruction of forests and forests by forest fires or at the hands of human beings, who make use of the land for construction or industrial activities.

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

Temperature rise

The increase in water temperature causes a decrease in oxygen that endangers the life of the organisms that inhabit it.

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

Transportation systems

Maritime transports can experience fuel leaks, dumping toxic substances and waste into the sea. Waste and garbage from pleasure boats are the main pollutants, not to mention the noise pollution caused by 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 air pollution.

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

Consequences of water pollution

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

Health effects

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

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

Impact on biodiversity

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 by suffocation or poisoning when ingesting toxic substances and residues.

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.


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 dissolved oxygen in the water, putting the lives of other species at risk.

Effects on the economy

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

The contamination of fish, shellfish and food taken from the sea prevents them from being put into trade and causes great losses to the fishing industry. Tourism also declines on the coasts infected by dumping of garbage, oil or the excessive presence of algae.