Soil Pollution: Causes, Effects, Preventive Measures

Soil Pollution

Soil pollution refers to the presence of toxic chemicals, also known as pollutants or contaminants, in soil. These chemicals are present in concentrations that are sufficiently high to pose a risk to both human health and the ecosystem. Soil pollution can occur even when naturally occurring contaminants are present in soil, as long as their levels exceed the natural levels and pose a potential risk.

It is essential to have an understanding that all soils have components that are capable of causing illness or death in human beings as well as in other forms of life. However, the concentration of such compounds in unpolluted soil is so low that they do not provide any danger to the environment that is nearby. When the presence of one or more of these hazardous compounds in the soil reaches a concentration high enough to be harmful to living creatures, we refer to that state as “contaminated soil” or Soil pollution.

The presence of numerous health hazards makes it a significant environmental concern. A case of consideration is that the likelihood of developing leukemia increases when individuals are exposed to soil that contains higher amounts of benzene.

What is soil pollution?

Soil pollution refers to any factors that result in the release of contaminants into soil, leading to a deterioration in its overall quality. Soil pollution is characterized by the degradation of soil quality due to the presence of pollutants, resulting in the unsuitability of the soil for the survival and survival of microorganisms and macroorganisms residing within it.

Soil pollution also referred to as soil contamination, can arise from anthropogenic activities or natural phenomena. However, the primary cause can be attributed to human activities. Soil pollution can arise as a result of the excessive presence of various chemicals, including pesticides, herbicides, ammonia, petroleum hydrocarbons, lead, nitrate, mercury, naphthalene, and others.

Causes of soil pollution

1. Industrial activity

Over the past century, industrial activity has emerged as the primary catalyst for soil contamination. The consequence of this phenomenon has been an increase in mining and manufacturing activities. A significant proportion of businesses depend on the extraction of minerals from subterranean sources. The product obtained as a consequence of this procedure is accompanied by a substantial quantity of waste. The presence of litter is widespread across the Earth’s surface. Both iron ore and coal produce polluted by-products that are not adequately disposed of. Consequently, the presence of industrial waste persists on the soil surface for an extended duration, thereby rendering it unsuitable for human consumption.

2. Agricultural activity

The utilization of chemical substances has experienced a significant increase due to advancements in technology, which have facilitated the development and availability of modern pesticides and fertilizers. These substances contain synthetic compounds that are not naturally occurring and are resistant to degradation. Consequently, upon their combination with water, they infiltrate the soil and gradually diminish its fertility. Various chemical substances have the potential to adversely affect the composition of the soil, rendering it more susceptible to erosion caused by water and air. Plants have the capacity to uptake a significant amount of pesticides, which subsequently contribute to soil pollution upon their decomposition, thereby integrating into the terrestrial environment.

3. Unmanaged waste disposal

In the present context, there is a growing concern regarding the issue of proper waste disposal. In addition to current waste, human waste also contributes to soil contamination. Every human contributes to soil pollution through the release of individual byproducts, such as urine and feces. A significant portion of the waste generated by diapers is disposed of in both sewer systems and landfills. Certainly, the sewer system also terminates at the landfill site, where the organic waste contaminates both the soil and water. The disposal of human waste in landfills leads to soil contamination, as our bodies accumulate toxins and chemicals in this process. Plastic waste, commonly referred to as “plastic contamination,” significantly contributes to the degradation of soil health. Nevertheless, despite its numerous applications, the pervasive culture of disposability surrounding it has become a significant global concern. Plastic bags and food wrappers possess a relatively short lifespan, ranging from minutes to hours, but their persistence in the environment can extend for numerous years.

4. Acid rain

The only source of wealth for land-based life is the environment around it, specifically the soil. In addition, when it loses its structure and composition, it has a negative impact on the entire ecosystem. Together with water vapor in the sky, airborne pollutants such as nitrogen oxides and sulfur dioxide produce acid rain, which then falls to the ground. As the name suggests, the water that was produced by this deluge is acidic. When this is absorbed by the soil, a great deal of vital nutrients are dissolved resulting in soil pollution. The barrenness of the landscape is a direct result of the deficiency of nutrients in the soil, which prevents the full development of crops. A barren landscape serves little purpose other than as a dump for rubbish.

5. Oil leakage

When chemicals are being stored or transported, there is always the risk of oil spills. This is most commonly found in places like gas stations. The gasoline contains compounds that lower the quality of the soil, making it unfit for cultivation and rendering it useless. Because of the potential for these pollutants to seep into the groundwater through the soil, the water may become undrinkable.

Soil Pollutants

The term “xenobiotic” refers to the most dangerous of the contaminants that can contaminate soil. They are man-made chemicals that do not occur naturally in the environment and are produced through the chemical synthesis process by humans. The term “xenobiotic” originates from the Greek words “xenos,” which means “foreigner,” and “bios,” which means “life.” Xenobiotics compounds include:

  • Heavy metals: Metals are commonly found in soil, and when the levels of heavy metals, such as lead and mercury, become excessively elevated, it poses a significant concern for human health. These heavy metals can enter the human body through food consumption, leading to the development of diseases, including cancer. In addition to heavy metals, the presence of elevated concentrations of other metals in soil is regarded as toxic. An increased concentration of any metal element poses significant challenges to human health and well-being. The metals are derived from various sources, encompassing mining operations, agricultural practices, disposal of electronic waste, and disposal of medical waste.
  • Pesticides: The application of pesticides by agricultural practitioners for pest control purposes has been found to contribute to soil pollution. Toxic substances are employed for the purpose of exterminating pests. Pesticides are employed in agricultural practices to assist farmers; however, excessive utilization of these substances can give rise to significant ramifications. The presence of these chemicals poses a significant risk to human health, as they have been linked to the development of a range of diseases, including those affecting the central nervous system, immune system, and cancer.
  • Industrial chemicals and waste: Industrial waste encompasses the discharge of waste materials, both directly and indirectly, into soil environments by diverse industrial sectors.  Soil pollution occurs when the chemical and waste materials resulting from industrial processes are discharged into the soil.
  • Petroleum hydrocarbons: Polycyclic Aromatic Hydrocarbons (PAHs) are a class of organic compounds composed solely of carbon and hydrogen atoms. The chemical structures of these compounds exhibit the presence of multiple aromatic rings. Polycyclic aromatic hydrocarbons (PAHs) have been found to be associated with a range of malignancies, encompassing diverse forms of cancer. Furthermore, there exists a correlation between PAH exposure and the development of various cardiovascular disorders. Polycyclic aromatic hydrocarbons (PAHs) are introduced into the soil via various pathways, including coal processing, vehicle emissions, incineration of plastics in landfills, cigarette smoke, and petroleum oil extraction.

Effects of soil pollution

1. Effects on human health

The contamination of soil has substantial implications for human well-being, as it serves as the foundation for our sustenance and survival. Crops and vegetation cultivated in contaminated soil play a substantial role in the absorption of pollutants, subsequently transferring these contaminants to humans through consumption. Prolonged exposure to such an environment can impact the genetic composition of the organism, thereby leading to congenital disorders and chronic health conditions. Furthermore, it is important to note that this substance has the potential to induce severe nausea in animals and subsequently lead to food contamination. Soil contamination also results in widespread food shortages and unproductive landscapes in cases where plants are unable to thrive in such conditions.

2. Effects on plants

The equilibrium of an ecosystem is impacted by the widespread contamination of the soil. The majority of plant species are unable to rapidly adapt to changes in soil conditions within a short period of time. Microorganisms, such as fungi and bacteria, that bind soil particles together, exhibit a reduction in growth. This exacerbates the problem of soil erosion.

3. Water Sources Contamination

Following precipitation, surface run-off transports contaminated soil particles and subsequently infiltrates various water bodies. Therefore, it has the potential to result in the contamination of subterranean water sources, consequently leading to the occurrence of water pollution. The water becomes unsuitable for both human and animal consumption following contamination, primarily due to the presence of hazardous chemicals.

4. Toxic dust

The release of noxious and malodorous gases from landfill sites has detrimental implications for the environment and poses significant health risks to certain individuals. Moreover, the malodorous scent results in inconvenience for individuals in close proximity.

5. Decreased soil fertility

The presence of soil contamination has been observed to have a negative impact on both the quantity and quality of agricultural yields. This poses a threat to global food security. The presence of toxic synthetic compounds in soil has a detrimental effect on its fertility, resulting in a decrease in agricultural productivity. The contaminated soil is subsequently utilized for cultivating crops that require essential nutrients for growth. These products may also contain potentially hazardous substances, posing a risk to the well-being of individuals consuming them.

6. Change in soil structure

The extensive application of pesticides and synthetic fertilizers contributes to the decline of numerous soil microorganisms, such as nightcrawlers. This results in the alteration of the soil structure. Moreover, it may also compel other hunters to relocate to alternative areas in search of sustenance. Fluctuations in soil pH have a significant impact on plant growth and productivity. During the designated period, the soil undergoes a state of desolation.

7. Effects on underground water

Soil contamination has an additional detrimental impact on the underground water table. Given that this water is stored beneath the layers of soil, it is plausible for contaminants present in the soil to gradually and consistently infiltrate the water table. The water obtained from both traditional wells and boreholes is contaminated. The excessive and prolonged use of contaminated water leads to a myriad of health issues. Over a certain period of time, the consumption of toxic underground water has been identified as the primary cause of various infections, such as arsenic poisoning and food contamination.

Preventive measures for soil pollution

1. Proper waste management

The implementation of appropriate waste management practices, encompassing both industrial and residential sectors, represents a highly efficacious approach to mitigating soil pollution. This assertion holds particular validity in relation to the management and elimination of toxic and perilous waste materials. Efficient disposal methods for waste encompass various practices, such as the appropriate recycling of batteries, consumption of sustainable foods, creation of homemade compost, and the authorized disposal of medicines.

2. Recycle and reuse

These steps not only serve to decrease the generation of waste but also contribute to the reduction of soil pollution. At present, plastics constitute a substantial proportion of the waste generated. Frequently, this waste is disposed of by being buried in landfills. Within these landfill sites, the process of decomposition for plastics and other materials occurs at a notably sluggish rate, resulting in the gradual release of hazardous substances into the surrounding soil. The deleterious nature of these toxic substances poses significant risks to soil health, thereby serving as a prominent contributor to soil pollution. The practice of reusing and recycling items would result in a decrease in the amount of waste deposited in landfills, thereby mitigating soil pollution.

3. Good farming practices

Natural excrement is benign and potentially the optimal source of nutrients for the soil. It introduces essential nutrients to the soil and restores its overall health. This substance does not possess any deleterious effects that could adversely impact soil quality or the environment in any manner. The addition of organic matter to soil enhances its fertility, but an excessive amount of organic matter can have detrimental effects on soil health. It yields more negative consequences than any positive outcomes, and results in soil pollution. The proliferation of artificial composts disrupts the pH equilibrium of the soil. It eradicates the beneficial microorganisms residing in the soil. The overflow of the surface from these soils also leads to water contamination, which in turn affects aquatic plants and animals.

4. Practical forest management

Preservation of forested areas plays a crucial role in addressing soil contamination. In the absence of trees, the terrestrial environment experiences desiccation and undergoes erosion. Therefore, it is imperative to prioritize the implementation of viable forestry practices, such as sustainable logging or ranger services, in order to mitigate soil contamination. It is evident that due to the continuous growth of the global population, there is an increasing demand for additional space for human expansion. This is often achieved at the cost of compromising the integrity of the soil. The implementation of reforestation efforts in a previously deforested area is currently being promoted.  The promotion of afforestation is recommended for infertile land areas. The subterranean structures of plants serve to bind soil particles and effectively entrap beneficial microorganisms within the soil matrix. Furthermore, it ensures the preservation of the subterranean aquifer.

5. Reduced use of chemical fertilizers

Chemical fertilizers have been found to have a greater detrimental impact rather than beneficial. Appropriate quantities of soil amendments can enhance soil fertility, whereas excessive amounts have the potential to induce toxicity and can cause soil pollution. The overapplication of chemical fertilizers has the potential to adversely impact soil health through various mechanisms. The capacity to influence the pH levels of soil is present.



About Author

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Kabita Sharma

Kabita Sharma is a graduate student from the central department of chemistry, Tribhuvan University. She has been actively involved in research related to natural products, computational chemistry, and nanochemistry. She is currently working on enzyme assay, molecular docking, and molecular dynamic simulation.

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