Soil pollution occurs when a substance (solid, liquid, or gaseous) is discharged, released, or deposited in the environment in such a way that it changes the environment. Agriculture (excessive/improper use of pesticides), excessive industrial activity, and poor waste management or inefficient waste disposal are all common sources of soil pollution. Majority of the sources of soil pollution are due to anthropogenic activities. This article will explain to you about the Sources of Soil Pollution which will be helpful in preparing the Environment syllabus for the UPSC Civil service exam.

What does Soil Pollution mean?

• Soil pollution is defined as the "adding of substances to the soil that has a negative impact on the physical, chemical, and biological aspects of the soil and lowers its productivity."
• It's a build-up of poisonous compounds, chemicals, salts, radioactive materials, or disease-causing agents in the soil that harm plant development and human and animal health.
• Soil naturally contains few harmful chemicals.
• The amounts of contaminants found naturally in soil are not high enough to constitute a risk.
• Soil pollution can also be defined as when the levels of contaminants in soil surpass the levels that should be present naturally.

Sources of Soil Pollution

Industrial Wastes

• The three categories of industries that generate the most industrial waste are metallurgy, non metallurgy, and food processing.
• The waste generated varies in every industry, depending on the raw materials utilized, manufacturing methods, and product outputs, but these wastes can be divided into three types: solids, liquids, and gasses.
• It has high toxic contaminants such as dirt and gravel, masonry and concrete, scrap metal, oil, solvents, chemicals, scrap lumber, even vegetable matter from restaurants.
• If these industrial wastes are dumped into the environment without being treated, major environmental issues may arise.
• This will surely reduce soil productivity and have a negative impact on agricultural production in the surrounding area.

*To know more about the topic, click this link Industrial Wastes

Pesticides

• Pesticides are toxic chemicals that are used to destroy pests.
• Pesticides have the potential to alter the composition, diversity, and basic function of essential soil microorganisms.
• Enzymes that catalyse biochemical transformations are produced by soil microorganisms and plants.
• These enzymes are the drivers of carbon and nitrogen cycling.
• Some pesticides have been shown to interfere with enzyme production, suppressing some while promoting others, affecting soil fertility, nutrient cycling, and metabolism.
• Pesticides have also been shown to have an impact on larger animals that assist in preserving the soil's structure and fertility.

*To know more about the topic, click this link Pesticides

Fertilizers and Manures

• Fertilizers and manures are substances that are applied to crops for enhancing their productivity and yield.
• Manures come from natural sources, whereas fertilizers are generated synthetically in factories.
• However, the fertilizers and manures when applied in the inappropriate time and quantity and when they contain harmful chemicals will pollute the soil and affect the nature and composition drastically.
• They can contribute to soil acidity and soil crust, lowering organic matter, humus content, and beneficial species, limiting plant growth, modifying soil pH, increasing pests, and even causing greenhouse gas emissions.
• The loss of humus reduces the soil's ability to store nutrients. Greenhouse gas emissions caused by excessive nitrogen fertilizer use can damage the atmosphere.
• Nitrogen fertilizers applied in high quantities to fields over time destroy the equilibrium between the three macronutrients, N, P, and K, resulting in lower crop yields.

*To know more about the topic, click this link Fertilizers and Manures

Radioactive Wastes

• Any material that is naturally radioactive or has been polluted by radioactivity and is assessed to have no further utility is considered radioactive waste.
• Nuclear reactors, fuel processing plants, hospitals, and research centers all produce radioactive (or nuclear) waste.
• Disposal into the ground has occasionally proven to be the most practical and simplest technique.
• However in many cases, the radionuclides enter the soil either directly or indirectly through water seeping via the soil and leaching pollutants from the surface of solid waste buried without adequate protection.
• The soil and its associated pore become contaminated regardless of how the release happens, which leads to an exceptional case.
• The radioactive materials in this form of waste may react with soil components, making it very toxic and unproductive.
• Because the abiotic and biotic components of the ecosystem are linked through nutrient cycles and energy flow, soils contaminated with radionuclides lose their potential to produce high-quality agricultural products and are thus categorised as degraded.

*To know more about the topic, click this link Radioactive Wastes

Other Sources

Mining Activities

• The extraction of mineral resources in mining is usually accomplished by underground or open cast mining.
• As a result, the operations necessitate excavation, from which dust may fall.
• Since the dust is not limited to the area where mining activities took place, it pollutes the soil once it rises and settles to the ground.

Plastics

• Plants, animals, and humans are all at risk from plastic waste. Only a small percentage of plastic is recycled, with the rest ending up in landfills.
• It takes 1000s of years to degrade, and even then, harmful compounds contaminate the land and water.
• Plastic bags build up in the soil and prevent seeds from germinating.
• When plastic is burned in landfills, highly toxic and dangerous gasses such as carbon monoxide, carbon dioxide, phosgene, dioxins, and other poisonous chlorinated compounds are released.
• After burning, toxic solid residue remains in the soil. Through chemical processes, hazardous gasses penetrate soils and severely pollute them.

Microbeads

• Microbeads are solid plastic particles smaller than one millimeter in diameter.
• Polyethylene and other petrochemical plastics make up the majority of them.
• Personal care products, toothpastes, and health research projects all contain microbeads.
• These products when discarded cause harm to the soil by polluting them to a greater extent.
• Many nations, including Canada, Ireland, the Netherlands, and the United Kingdom, have prohibited the manufacture of microbead-containing products.

Impact of Soil Pollution

On the Environment

• Soil pollution is harmful to the ecosystem and has implications for all forms of life that come into contact with it.
• Unsustainable agriculture methods that deplete soil organic matter can allow toxins to enter the food chain more easily.
• For example, contaminated soil can discharge pollutants into groundwater, which accumulate in plant tissue and are subsequently passed on to grazing animals, birds, and humans that consume the plants and animals.

On the Soil

• A chain reaction occurs when soil pollution occurs.
• It affects soil biodiversity, lowers soil organic matter, and reduces soil filtering capacity.
• It also contaminates water held in the soil and groundwater, resulting in nutrient imbalances in the soil.

On Agriculture

• Soil pollution has an influence on food security because it impairs plant metabolism, lowering crop production.
• They make crops dangerous for animals and humans to eat.
• Pollutants also impair soil biodiversity and fertility by directly harming soil microbes and larger soil-dwelling species.
• Pollutants also impair soil biodiversity and fertility by directly harming soil microbes and larger soil-dwelling species.
• The soils' ability to cope with pollutants will also become too low.

On Human Health

• Pollutants in the soil, groundwater, and food supply can cause a wide range of diseases and deaths in humans..
• Short-term health effects from exposure to such soils include headaches, coughing, chest pain, nausea, and skin/eye irritation.
• Long-term exposure to contaminated soil can cause central nervous system depression, damage to essential organs (such as the liver) and even cancer.

Conclusion

We are polluting our future by polluting our soils. Soil is a finite resource, which means that it cannot be replaced within a human lifetime. Because of erosion, loss of soil organic carbon, salinization, compaction, acidity, and chemical pollution, one-third of our soils are moderately or severely degraded today. We won't be able to produce more soil in our lifetime since it takes around 1000 years to form 1 centimeter of top soil. We are accountable for the soils that provide us with food, water, and air, and we must take action to guarantee that we have healthy soils for a future that is both sustainable and food secure.