We explain what the causes of pollution are, why the various types of pollution occur and their consequences.
What is pollution and what types are there?
Pollution is the entry of substances into an environment, which affects your 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 present in high concentrations.
Pollution can be natural (caused by forest fires, volcanic eruptions, tsunamis or earthquakes) or artificial (caused by human activity: the interruption of the natural cycles of the ecosystem, the misuse of natural resources or mismanagement of waste, among the main causes).
Causes of environmental pollution
Environmental pollution is produced, to a greater extent, by the continuous increase in human population and 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 pollutants. They come from the chemical industry that generates toxic products, for example acids, solvents, plastics, petroleum derivatives and pesticides.
- Physical pollutants. They come from phenomena caused by human activity, for example noise, radioactivity, heat, and electromagnetic energy.
- Biological pollutants. They come from the decomposition and fermentation of organic waste, for example excrement, factory waste, and sewers.
Causes of the contamination of the water
Water pollution occurs when it is no longer fit for consumption due to a large amount of toxic substances that are thrown into water bodies or that reach groundwater through seeps in the ground. The polluting factors of water are:
- Sewage discharges. They come from sewage, urban and industrial fluids that are not treated properly.
- Oil spills. They come from oil drilling that has 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 they reach the groundwater or napas.
- Deforestation. The indiscriminate felling of trees causes the appearance of sediments and bacteria under the ground, which seep through the ground until they reach the groundwater and contaminate it.
- The rise in temperature. Thermal pollution is the exacerbated alteration of the temperature that causes a decrease in oxygen in the water, and alters its entire composition.
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 world’s leading cause of air pollution).
The air in the atmosphere naturally contains gases such as nitrogen, oxygen, carbon dioxide and methane, which make the greenhouse effect possible: they retain as heat some of the solar rays that pass through the atmosphere. Thus, 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 solar rays would bounce directly off the earth’s surface and the average temperature would be -18º C, so the life we know today would not be possible.
The problem that air pollution generates in the greenhouse effect is the increase of some gases such as carbon dioxide and methane. This unbalances the natural composition of the atmosphere and causes solar radiation to be trapped on a larger scale, causing higher than normal temperatures. As a consequence, the glaciers melt and there are climatic changes and floods, among others.
The main sources of polluting gases are:
- The extraction of hydrocarbons from the oil, coal and gas fields.
- Combustion of fuels (transportation)
- The digestive process of cattle by the massive agricultural-livestock industry.
- Microbial activity in sewage waters (sewers).
- The burning of tropical forests and savanna (forest fires).
Causes of soil contamination
The causes of soil contamination are related to increased chemical compounds that come from human activity and that cause detrimental changes on the ground.
Some examples of soil contamination are:
- Underground storage tanks. They contain, for the most part, liquids and gases derived from petroleum that usually come into contact with the ground due to leaks from the pipes. 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 cannot filter them in a natural way.
- Pesticides. They contain a large amount of chemicals that are harmful to the environment and are absorbed by the earth until they reach groundwater. Despite being the main cause of soil contamination, they are used in the agricultural industry, along with pesticides and fertilizers, to combat pests and worms.
- Urban waste. They consist of domestic and commercial garbage that, for the most part, are not treated in an adequate way to avoid their negative environmental impact. Waste that cannot be decomposed due to its chemical composition, remains for hundreds of years on land and in 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 legislation for the control of industrial waste, 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 air and soil contamination due to chemicals and wastes that are not properly treated and stored (they seep into the earth and reach groundwater).
Consequences of pollution
Environmental pollution generates problems in health, climate, soil, plants and other animals. In March 2017, the World Health Organization reported that nearly two million child deaths occur annually as a result of environmental pollution.
Unsanitary environmental conditions, polluted air (indoors and outdoors), exposure to second-hand tobacco smoke, contaminated water, and poor health and hygiene are some of the main polluting factors.