What is the cause of soil pollution? Human activities are the primary cause of land degradation and soil pollution. By the end of this topic, you will learn how different forms of human activities are responsible for the majority of different types of soil pollution.
Soil, Soil Pollution and Pesticides
Soil pollution has gradually become a major challenge which we need to overcome to establish a healthy environment. The weathering of the earth’s crust by various processes leads to the formation of soil that has accumulated over centuries. Soil is home to a large proportion of bacterial biodiversity and other micro and macro organisms.
However, let us consider our country India. Indian economy is largely dependent on agriculture. Thus, we give very high priority to the development of Indian agriculture, fisheries and livestock. Therefore, it is very important to protect the crops from any damage caused by insects, weeds, rodents and other crop diseases for surplus production.
So, how do we protect crops? The very obvious answer is insecticides and herbicides. However, did you know that these pesticides and herbicides are a major cause of soil pollution? Therefore, it is very important to use pesticides judiciously as they contain a lot of different harmful chemicals. Therefore, it is important to limit the use of insecticides and herbicides to improve soil and prevent soil pollution.
Definition of soil pollution
Soil pollution refers to anything that causes soil contamination and reduces soil quality. It occurs when the pollutants that cause pollution reduce the quality of the soil and convert the soil into habitable soil for the microorganisms and macro organisms that live in the soil.
Soil pollution or soil pollution can be either due to human activities or due to natural processes. However, it is mostly caused by human activities. Soil contamination can occur due to the presence of high amounts of chemicals like pesticides, herbicides, ammonia, petroleum hydrocarbons, lead, nitrates, mercury, naphthalene etc.
The primary reason for soil pollution is the lack of awareness among the common people. Thus, soil will lose its fertility due to many different human activities such as overuse of pesticides. In addition, the presence of additional chemicals will increase the alkalinity or acidity of the soil leading to degradation of soil quality. This in turn will lead to soil erosion. This soil erosion refers to soil pollution.
Due to soil pollution
Soil pollution can be caused by natural or human activities. However, it mostly boils down to human activities that cause most of the soil pollution such as heavy industry, or pesticides in agriculture.
Before World War II, the chemical nicotine present in tobacco plants was used as a pest control substance in agricultural practices. However, during World War II DDT was found to be extremely useful for malaria control and pest control of many insects. Hence, it was used to control many diseases.
Therefore, after the war, people started using it as a form of pest control in agriculture to kill rodents, weeds, insects etc. and to avoid the damage caused by these pests. However, everyone gradually banned this chemical in many parts of the world including India due to the ill effects of this chemical.
In addition, the regular use of chemicals caused the pests to become resistant to DDT. So it introduced other harmful chemicals like aldrin and dieldrin. Pesticides are synthetic toxic chemicals that certainly kill a variety of pests and insects that harm agriculture but have many ecological effects.
They are generally insoluble in water and non-biodegradable. Therefore these chemicals will not decompose slowly and will continue to accumulate in the soil. Therefore, the concentration of these chemicals will increase when these chemicals are transferred from lower to higher trophic level through the food chain. Therefore, it will cause many metabolic and physiological disorders in humans.
Chlorinated organic toxins
The harmful effects of DDT and other chemicals led to the introduction of less permanent organic and more-biodegradable substances such as carbamates and organophosphates. However, these chemicals act as harmful toxins to nerves, so they are more dangerous to humans. This led to pesticide related deaths of farm workers in some agricultural areas.
Learn about the causes and effects of water pollution here.
Gradually, industries started producing herbicides like sodium arsenite (Na3AsO3), sodium chlorate (NaClO3) etc. Herbicides can decompose over a period of a few months. However, they also affect the environment and are not eco-friendly. Even though they are not as harmful as organo-chlorides, most herbicides are toxic. They are known to cause birth defects.
In addition, research shows that herbicide spraying leads to more insect attacks and diseases of plants than manual weeding. One thing to note here is that all the above factors occupy a small part of the causes. Most of the causes are related to manufacturing activities in chemical and industrial processes that are released into nature or the environment.
Excessive use of inorganic nitrogen fertilizers leads to soil acidification and contamination of agricultural soils. Also known as agricultural chemical pollution.
The wrong way to dispose of chemical waste from a variety of industries can lead to soil contamination. Such human activities have led to acidification and pollution of soil due to disposal of industrial wastes, heavy metals, toxic chemicals, dumping oil and fuel etc.
Inferior irrigation systems
Poor irrigation methods increase the salinity of the soil. In addition, excess water, improper maintenance of canals and irrigation channels, lack of crop rotation and intensive cultivation gradually reduce the soil quality over time and cause land degradation.
Disposal of plastic, cans and other solid waste comes under the category of soil pollution. Disposing of electrical items like batteries adversely affects the soil due to the presence of harmful chemicals. For example, the lithium present in a battery can cause soil leaching.
Lack of proper waste disposal, regular construction due to lack of proper drainage and surface runoff can cause excessive damage to the soil. These wastes dumped by humans consist of chemical waste from residential areas. In addition, leakage from the sewerage system can also affect the quality of the soil and cause soil pollution by changing the chemical composition of the soil.
After Effects of Soil Pollution
Soil pollution is not only a problem in India but it is a global problem. It has harmful effects on the soil and environment at large. Soil contamination will reduce the agricultural production of the land. The major soil pollution after effects are:
Inferior crop quality
This can reduce the quality of the crop. Regular use of chemical fertilizers, inorganic fertilizers, insecticides will rapidly reduce soil fertility and change the soil structure. This will lead to the degradation of soil quality and poor quality of crops. Over time the soil will become less productive because of the accumulation of toxic chemicals in excess.
Harmful effects on human health
This will increase the exposure to toxic and harmful chemicals thereby increasing the health hazards for the people living nearby and on the poor land. Living, working or playing in contaminated soil can lead to respiratory diseases, skin diseases and other diseases. In addition, it can cause other health problems.
Water source contamination
The surface runoff after the rains will carry the polluted soil and enter various water resources. Thus, it can cause ground water contamination leading to water pollution. This water after being contaminated is not suitable for human and animal use due to the presence of toxic chemicals.
Negative impact on ecosystem and biodiversity
Soil pollution can cause imbalance of soil ecosystem. Soil is an important habitat and is home to a wide variety of microorganisms, animals, reptiles, mammals, birds and insects. Thus, soil pollution can negatively affect the life of living organisms and result in the gradual death of many organisms. It can pose a health threat to animals grazing in contaminated soil or to microorganisms living in the soil.
Therefore, human activities are responsible for most of the soil pollution. We as human beings buy things that are harmful and not necessary, use agricultural chemicals (fertilizers, pesticides, herbicides, etc.), throw garbage here and there. Without being aware, we harm our own environment.
Therefore, it is very important to educate the people around you about the importance of environment if they are not aware. Preventing soil erosion will help prevent soil pollution. Thus, it is our small steps and activities that can help us achieve a healthier planet for us. It is therefore essential for industries, individuals and businesses to understand the importance of soil and prevent soil pollution and devastation to plant and animal life.
Question: List some preventive measures of soil pollution?
- Using the right farming techniques
- Recycling of waste before disposal
- Method of proper disposal of domestic and industrial waste
- Use of organic fertilizers in place of chemical fertilizers and pesticides
- Community Education and Awareness
- Proper maintenance of sewage system