What is Environmental Pollution (Main Causes and Examples)

What is environmental pollution

Environmental pollution happens when harmful physical, chemical and biological substances are introduced into the environment. Human activity and some natural disasters can also contribute to this.

harmful substances alter environmental conditions, affecting ecosystems, the temperature and quality of soil, water and air. These changes can cause unwanted effects, negatively impacting health, welfare and habitability of living beings.

Polluting agents can be chemical substances, such as pesticides and herbicides, oil, gases, urban waste, among others. However, there are other sources of pollution that also affect the environment, such as the clearing of forests or the use of light at night.

Urban waste in the Santiago River, in Jalisco, Mexico (Credits: Red Waterlat-Gobacit, FLICKR)

Environmental pollution is generally associated with the economic and social development of nations. The more developed a country is, the more pollution it usually generates through waste, gas emissions, dumping of chemical products, etc. The effect is more pronounced when pollution occurs without considering the consequences it has on the environment.

Hence it is argued that Sustainable development is the ideal way to progress for the next decades. That is, paths of technological development are sought with the protection and renewal of the environment in mind.

There are legislations and treaties, both nationally and internationally, whose objective is to control the generation of polluting substances. For example, the Kyoto Protocol seeks to reduce greenhouse gas emissions to prevent global warming.

Main causes of environmental pollution

There are quite a few factors that influence environmental pollution. Broadly speaking, the most common causes that generate this pollution are:

Residuous generation: the accumulation of waste of all kinds, especially plastic, chemicals and radioactive elements, damages the environment. The problem is greater when non-biodegradable materials are discarded, as they remain in soils or bodies of water for years and even centuries. This type of pollution happens in all cities and towns, but it also occurs in industrial complexes, coasts and oceans.
Toxic gas emission: The burning and use of fossil fuels are the major contributors to gas emissions. The main causes of this type of pollution are industries, factories and vehicle traffic, especially if they are old vehicles.
Black water discharge: Also known as wastewater or sewage, these are generated anywhere that contains a sewage system. If this system is not well designed, sewage can contaminate soil, groundwater and nearby rivers.
Excess artificial light: due to urbanization, the nights are full of artificial light. This affects the night life of some living beings, disorienting them or altering the sleep cycle.
Forest slashing and burning: The presence of trees helps purify the air and close the oxygen and carbon cycle. They also humidify the environment, absorb excess water and help enrich the soil. For that reason, cutting down and burning forests is a type of environmental pollution. In the long term, this activity affects the quality of the soil and air in the area, as well as the temperature.
The indiscriminate exploitation of natural resources: Extracting resources without control, destroying the environment in the process, is another common cause of environmental pollution. As time passes, the area’s ecosystems deteriorate, and species migrate or even become extinct.

All these activities are linked to industry, mining, agriculture, commerce, oil exploitation, as well as the daily life of human beings.

Main consequences of environmental pollution

Pollution has harmful effects on the environment. The main consequences are:

Loss of soil, water and air quality, caused mostly by the generation of waste. These wastes, if not treated or stored correctly, interfere with the environment in a negative way. For example, plastic, since it is not biodegradable, remains in the oceans for centuries, affecting marine ecosystems. In the case of chemical substances, these can degrade soils so that they lose their fertility.
Alteration of ecosystems and disappearance of species, since living beings are sensitive to environmental pollution. Changes in the ecosystem modify the favorable conditions that some living beings need to live and reproduce. As a result, species may end up migrating or even become extinct.
Deterioration of people’s health, something that is linked to the loss of soil, water and air quality. Human beings also suffer the consequences of environmental pollution. For example, toxic gas emissions cause respiratory and cardiovascular problems. Another example is water contamination, as it reduces its drinkability, making it unfit for consumption.
Increase in global warming, caused by the emission of toxic gases. These gases, known as greenhouse gases, deplete the ozone layer and contain ultraviolet rays in the atmosphere. Consequently, the Earth’s surface gradually overheats as the years go by, increasing the average temperature of the Earth and melting the polar caps.

Examples of environmental pollution

In our daily lives, whether consciously or unconsciously, we can contribute to environmental pollution.

An example is when we litter in parks and in the mountains, instead of disposing of waste in designated bins. This garbage has a negative impact on the environment, since it alters the ecosystem. If other people do the same and this garbage accumulates, some species may migrate and certain plants may die.

Another example is when we use vehicles that use gasoline or diesel to operate. If we always go everywhere with our vehicle, we are emitting gases that cause global warming. This is more serious in older vehicles, since the combustion mechanisms are more optimized today compared to decades ago.

We also pollute when we hold large-scale open-air nighttime concerts. The large number of lights and loud sound interfere with the fauna close to us, altering their night life and sleep cycle.

A final example of environmental pollution is the production of radioactive substances in nuclear reactors or plants. Radioactive waste not disposed of correctly, even if buried, affects fauna and flora. Over time, radioactive emissions alter the genetics of living beings, causing mutations or killing them in the process.

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Stephen graduated in 2017 in Biological Systems Engineering, and completed his master’s studies in Enabling Technologies for the Food and Bioprocess Industry in 2020. He studied both at EEAABB (Barcelona School of Agri-Food and Biosystems Engineering).