What is pollution and what types are there?

We explain to you what are the causes of pollution, why the various types of pollution occur and their consequences.

1. What is pollution and what types are there?

The pollution is the entry of substances into an environment, which affects balance and makes it an unsafe environment . An ecosystem , a physical environment or a living being is considered “environment” . The “pollutant” can be physical, chemical or biological and is harmful when it occurs in high concentrations.

Contamination can be natural (caused by forest fires, volcanic eruptions, tsunamis or earthquakes ) or artificial (caused by the activity of the human being : the disruption of natural cycles of the ecosystem, misuse of natural resources or mismanagement of waste, among the main causes).

2. Causes of environmental pollution

Environmental pollution is produced, to a greater extent, by the continuous increase of the human population and an uncontrollable industrial development . The presence in excess of any physical, chemical or biological agent in the environment causes an imbalance. Some examples of pollutants are:

• Chemical contaminants They come from the chemical industry that generates toxic products, for example, acids, solvents , plastics , petroleum products and pesticides.
• Physical pollutants They come from phenomena caused by the activity of man, for example, noise, radioactivity, heat and electromagnetic energy.
• Biological pollutants They come from the decomposition and fermentation of organic wastes, for example, excreta, factory waste and drains.

3. Causes of the contamination of the water

Water pollution occurs when it is no longer suitable for consumption due to a large amount of toxic substances that are thrown into the bodies of water or that reach groundwater through seepage into the ground. Water pollutants are:

• Black water spills. They come from sewage, urban and industrial fluids that are not treated properly.
• Oil spills. They come from oil drilling that have an accident or improper practice.
• Phytosanitary products They are used to spray the fields, such as pesticides and pesticides, which are then absorbed by the earth until reaching groundwater or water.
• Deforestation. The indiscriminate felling of trees causes the appearance of sediments and bacteria under the soil, which seep through the ground until they reach the groundwater and contaminate it.
• The temperature rise. Thermal pollution is the exacerbated alteration of temperature that causes a decrease in water oxygen, and alters its entire composition.

4. Causes of air pollution

The main causes of air pollution are related to the burning of fossil fuels (coal, oil and gas) that takes place in the extraction of oil wells, in the operation of the industrial sector and in road transport (the main cause global air pollution).

The air in the atmosphere contains naturally occurring gases such as nitrogen, oxygen, carbon dioxide and methane, which make the greenhouse effect possible: they retain some of the sun’s rays that pass through the atmosphere in the form of heat. In this way, the average temperature on Earth is 15º C , which allows the development of life. Without the greenhouse effect , that is, without the retention of solar radiation, the sun’s rays would bounce directly against the Earth’s surface and the average temperature would be -18º C, so the life we know today would not be possible.

The problem generated by air pollution in the greenhouse effect is the increase in some gases, such as carbon dioxide and methane

 . This imbalances the natural composition of the atmosphere and causes solar radiation to be retained on a larger scale, which causes higher temperatures than normal. As a consequence, glaciers melt and climate changes and floods occur, among others.

The main sources of polluting gases are:

• The extraction of hydrocarbons from oil, coal and gas fields.
• The combustion of fuels (transport)
• The digestive process of cattle by the massive agricultural-livestock industry.
• Microbial activity in sewage (sewers).
• The combustion of tropical forests and savanna (forest fires).

5. Causes of soil pollution

The causes of soil contamination are related to the increase in chemical compounds that come from the activity of man and that cause harmful changes in the soil.

Some examples of soil contamination are:

• The underground storage tanks. They contain, in their majority, liquids and gases derived from petroleum that usually come in contact with the earth due to filtrations of the conduits. Also, domestic deposits or wells that contain waste liquids are absorbed by the earth and, due to the intense flow with which they are discharged, the soil does not filter them naturally.
• Pesticides. They contain a large amount of chemicals that are harmful to the environment and are absorbed by the earth until they reach the groundwater. Despite being the main cause of soil contamination, they are used in the agricultural industry, together with pesticides and fertilizers, to fight pests and worms.
• Urban waste. They consist of domestic and commercial garbage that, for the most part, are not treated properly to avoid their negative environmental impact. The waste that due to its chemical composition cannot be decomposed, remains for hundreds of years in the earth and in the water, and is a danger to other animals and the ecosystem in general.
• Industrial waste They contain pesticides, chemical liquids and traces of fuels and metals that come from textile, paper, food and oil production. Despite the existence of regulations and laws for the control of industrial wastes, mass production exceeds the control capacity (both for emissions into the atmosphere and for liquids that are discharged into tributaries).
• Open pit mining. The work process of a mine generates enormous environmental impacts on the ecosystem such as certain changes in the morphology of the land or the contamination of the air and soil due to chemicals and wastes that are not properly treated and stored (seep into the ground and they reach groundwater).

6. Consequences of pollution

Environmental pollution causes problems in health, climate, soil, plants and other animals . In March 2017, the World Health Organization reported that almost two million child deaths occur annually as a result of environmental pollution.

The unhealthy conditions of the environment, polluted air (indoors and outdoors), exposure to second-hand smoke, contaminated water and lack of health and hygiene , are some of the main polluting factors.