Soil is one aspect of our planet that we rarely see because of the rise of concrete buildings and roads.

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It is known by many names such as dirt, mud, and ground, but it is no doubt very important to us. The plants that sustain us grow in soil. Therefore, it’s important to keep the environment healthy and clean. Among different types of pollution, there is also contamination of the soil. In this guide, we’ll focus on what it is, the causes and effects, and how one can reduce it.

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What to Know About Contamination

Soil pollution refers to the high concentration of pollutants found on the surface that affects the biodiversity of the land and causes human health problems, especially through food. In the same way that heavy metals and other substances contaminate the soil, activities such as stock breeding and intensive farming use chemicals, pesticides, and fertilizers that can pollute the soil. Man-made waste is the main factor responsible for contamination. Chemicals that are found in the contamination are solvents, hydrocarbons, pesticides, and so on.

Although nature produces waste such as dead plants and animals, they don’t pollute the soil, rather they act as a fertilizer that promotes the healthy growth of plants.

What Are the Causes of Contamination in Soil?

Some of the main causes of contaminants in soil are discussed below.

Industrial Dump

Since the advent of mining and manufacturing, the largest contributor to the problem has been industrial activity. Many industries rely on mining minerals to operate. Industrial waste stands in the soil surface for more than a year after it is generated, making it unfit for use. Whether it is iron ore or coal, the by-products are contaminated, and they are not disposed of properly. Therefore, the chemicals stay on the surface for long periods of time, making them completely unsuitable for use.

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Agricultural Waste

The agricultural industry uses pesticides and insecticides to protect the crops from being destroyed by insects and weeds, as well as herbicides, to control weed growth. This, in turn, can greatly pollute the soil due to the number of chemicals found in these products. The use of biosolids, which are treated sewage, as fertilizers has also been linked with soil decontamination.

Human Waste

The cause of contamination is also due to the disposal of waste, which is becoming increasingly dangerous. Industrial waste is an obvious source of contamination, but there’s another way in which you may be adding to the pollution. Human waste in the form of garbage is dumped into a landfill while some moves into the sewers. Both of which can easily contaminate the soil.

Oil Spills

In most fuel stations, oil leaks can be seen during the storage and transportation of chemicals. The chemicals present in the fuel deteriorate the soil’s quality, making it unsuitable for planting crops. These harmful chemicals can seep through the soil and pollute it. 

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Acid Rain

Acid rain is formed when sulphur dioxide reacts with nitrogen dioxide and water in the air to produce several acidic compounds. As pollutants in the air mix with rain, they wash back into the ground, damaging soil nutrients and changing the structure of the soil. Acid rain is caused when polluted water mixes with rain and falls to the ground. The polluted water enters the soil, which contributes to a toxic water table and poor growth of crops.

The Negative Effects of Soil Pollution

Human Health

As soil is indispensable for the existence of all living things, its contamination significantly affects our health. Crops and plants that are grown on polluted soil absorb most of the pollutants, which then affect us. During long-term exposure to such soil, the genetic makeup of the body may be altered, causing congenital illness and chronic illness that cannot easily be treated. The effect of this virus on livestock can be considerable, and it can also lead to food poisoning over time.

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Environment

Contaminated soil poses a much greater threat to the environment as well. Contaminated soil cannot be used to grow food because the chemicals can leach into the food and harm human health. Food grown on contaminated land will produce lower yields than if it were not contaminated. This, in turn, can cause even more damage because the soil will be devoid of plants, resulting in more erosion.

Decrease in the Fertility of the Soil

The chemicals present in the soil lead to a reduction in the fertility of the soil, which makes it unsuitable for agriculture and any local vegetation. Using contaminated soil leads to the production of fruits and vegetables that lack quality nutrients and may also contain poisonous substances that are harmful to human health if consumed.

Poisons the Water Table

Pollution of the soil can also poison the underground water table. The underground water table is beneath the layers of soil, so pollutants in the soil can easily permeate through them gradually and steadily. This water is consumed by humans, which can greatly compromise your health. The prolonged consumption of this toxic underground water can lead to diseases such as arsenic poisoning, food poisoning, and others. Some of these diseases can be fatal as well. 

Change in the Soil Structure

When many soil organisms die (e.g., earthworms) in the soil, other predators may have to search for food in different areas. This could have an impact on soil structure and soil biodiversity.

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How to Curb Soil Pollution

A complex problem such as soil pollution must be solved. We all need to understand the magnitude of soil’s importance for our lives. The earlier we realise this, the sooner we can find a solution to the problem of soil pollution. Here is how you can solve the problem of soil pollution.

1. Minimise the Use of Chemical Fertilizers

Despite being beneficial to the soil, chemical fertilizers kill the soil in excess. Although fertilizers in proper amounts can enhance soil fertility, excessive use can harm the soil in numerous ways. Overuse of chemical fertilizers could adversely affect the pH levels of the soil and destroy the microorganisms living in the soil. Therefore, the use of chemical fertilizers should be minimised.

2. Recycle Waste

Instead of dumping materials and plastics into landfills, recycle and reuse them to minimise land pollution as well as soil contamination. Plastics and other materials decompose slowly, releasing toxic substances into the soil. These toxic substances are extremely damaging to the soil and a major contributor to soil pollution.

3. Grow Trees

As the population grows, people need more and more space to expand their civilization, and this leads to soil pollution because soil erosion occurs from deforestation. It is natural that the ever-growing population creates an ever-increasing need for space. To solve the problem of soil erosion, afforestation should be promoted.

4. Go for Soil Remediation

Soil remediation is a process for reducing contaminants to levels that are safe for use, which means your site can be used without the risk of environmental contamination. Soil remediation encompasses a number of techniques, each employing a different technique to remove contaminants from soil. These techniques, however, each have their intended use. The different types of soil remediation are discussed below.

Encapsulation

In this process of soil remediation, contaminants are encapsulated to make sure they cannot spread further, as most remediation is accomplished by filtering contaminants from soils. Most encapsulation methods involve mixing lime, cement, and concrete with the contaminated soil to prevent other soil from getting in contact with the contaminants.

Despite its effectiveness, encapsulating soil precludes cultivation of any kind on the treated surface. Therefore, it should not be considered unless the soil isn’t going to be used to cultivate anything.

Thermal Soil Remediation

A thermal soil remediation method involves heating soil to a high temperature to remove specific types of contaminants. Soils contaminated with contaminated water or hydrocarbon compounds, such as oil or gasoline, are typically treated with this procedure, which is usually performed using an oven and conveyor belt. The method primarily involves baking the soil, decomposing the contaminants, and then capturing and cooling the extracted materials for later disposal. The remediated soil is then cooled and removed from the equipment by a conveyor system.

Bio Remediation

The bioremediation method is also an in situ remediation technique, but opposed, unlike mechanical methods, it uses a biological mechanism to remove contaminants. Engineered aerobic and anaerobic bacteria are used to treat contaminated soil in situ by feeding on the particular contaminant type that a parcel of soil contains.

Hydrocarbons and other contaminants in the soil are consumed and broken down by the bacteria. The method is very effective for in situ remediations, but it must work in an ideal setting for it to be effective.

Air Sparging

Soil remediation using air sparging is appropriate when contamination is caused by toxic gases or vapours. However, it differs from other methods of remediation in that it must be applied directly to the soil and not extracted for use.

The problem of soil pollution must be dealt with in a balanced way by both natural methods and environmental remediation techniques to prevent the soil from becoming contaminated.