Soil Pollution

In a general sense, soil pollution is the existence of toxic chemicals (pollutants or contaminants) in soil in high enough concentrations to be of risk to human health and/or ecosystem. Additionally, even when the levels of contaminants in soil are not of risk, soil pollution may occur simply due to the fact that the levels of the contaminants in soil exceed the levels that are naturally present in soil (in the case of contaminants which occur naturally in soil).
Created On: Aug 27, 2015 18:30 IST
Modified On: Dec 7, 2015 15:52 IST

Soil pollution occurs when humans introduce harmful objects, chemicals or substances, directly or indirectly into the soil in a way that causes harm to other living things or destroys soil or water ecosystems.

Soil pollutants include a large variety of contaminants or chemicals (organic and inorganic), which could be both naturally-occurring in soil and man-made. In both cases, the main soil pollution causes are the human activities (i.e., the accumulation of those chemicals in soil at levels of health risk is due to human activities such as accidental leaks and spills, dumping, manufacturing processes, etc.). Accumulation due to natural processes is also possible.

Various causes for soil pollution are detailed below. Of these causes, construction sites are important causes of soil pollution in urban area due to their almost ubiquitous nature. In general, any chemical handled at construction sites may pollute the soil. However, the higher risk come from those chemicals that may travel easier through air (as fine particulate matter) and which are resistant to degradation and bio-accumulate in living organisms such as PAHs. Additionally, construction dust may easily spread around by air and is dangerous due to its lower particle size (less than 10 microns). Such construction dust may trigger respiratory vilnesses, asthma, bronchitis and even cancer.

Causes of Soil Degradation

Soil Erosion: While erosion is a natural process often caused by wind and flowing water it is greatly accelerated by human activities such as farming, construction, overgrazing by livestock, burning of grass cover and deforestation.

Today both water and soil are conserved through integrated treatment methods. Some of the most commonly employed methods include the two types of treatment that are generally used.

  • Area treatment which involves treating the land
  • Drainage line treatment which involves treating the natural water courses (nalas) Continuous contour trenches can be used to enhance infiltration of water reduce the runoff and check soil erosion. These are actually shallow trenches dug across the slope of the land and along the contour lines basically for the purpose of soil and water conservation.

Excess use of fertilizers: It makes the soil friable and susceptible to erosion.

Excess salts and water: Excess irrigation causes water logging which results in salinisation of the soil.

Soil Pollution and Its Effects

Soil pollution may affect all of us as well as plants and animals. However, children are usually more susceptible. This is because kids are more sensitive to various pollutants and they may come in close contact with soil by regularly playing in the ground for example. Thus, soil pollution for kids always involves higher risks than for adults. While anyone is susceptible to soil pollution, soil pollution effects may vary based on age, general health status and other factors.

1. Effect on Health of Humans: Considering how soil is the reason we are able to sustain ourselves, the contamination of it has major consequences on our health. Crops and plants grown on polluted soil absorb much of the pollution and then pass these on to human beings. This could explain the sudden rise in small and terminal diseases.

Long term exposure to such soil can affect the genetic make-up of the body, causing congenital illnesses and chronic health problems that cannot be cured easily. In fact, it can sicken the livestock to a considerable extent and cause food poisoning over a long period of time. The soil pollution can even lead to widespread famines if the plants are unable to grow in it.

2. Effect on Growth of Plants: The ecological balance of any system gets affected due to the widespread contamination of the soil. Most plants are unable to adapt when the chemistry of the soil changes so radically in a short period of time. Fungi and bacteria found in the soil that bind it together begin to decline, which creates an additional problem of soil erosion.

The fertility slowly diminishes, making land unsuitable for agriculture and any local vegetation to survive. The soil pollution causes large tracts of land to become hazardous to health. Unlike deserts, which are suitable for its native vegetation, such land cannot support most forms of life.

3. Decreased Soil Fertility: The toxic chemicals present in the soil can decrease soil fertility and therefore decrease in the soil yield. The contaminated soil is then used to produce fruits and vegetables which lacks quality nutrients and may contain some poisonous substance to cause serious health problems in people consuming them.

4. Toxic Dust: The emission of toxic and foul gases from landfills pollutes the environment and causes serious effects on health of some people. The unpleasant smell causes inconvenience to other people.

5. Changes in Soil Structure: The death of many soil organisms (e.g. earthworms) in the soil can lead to alteration in soil structure. Apart from that, it could also force other predators to move to other places in search of food.

A number of ways have been suggested to check the current speed of pollution. Such attempts at cleaning up the environment require plenty of time and resources to be pitched in. Industries have been given regulations for the disposal of hazardous waste, which aims at minimizing the area that becomes polluted. Organic methods of farming are being supported, which do not use chemical laden pesticides and fertilizers. Use of plants that can remove the pollutants from the soil is being encouraged. However, the destination ahead is very far and the prevention of soil pollution will take so many years.

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