How Mineral Oil Pollution Disrupts Soil Health and Plant Growth
What is Soil Pollution?
Soil Pollution is the degradation of soil quality caused by different chemicals and toxic materials. The soil pollution caused by mineral oil is one of the serious problems faced by global environmentalists.
Mineral oil, besides other harmful wastes, causes soil pollution. How? During their extraction from the oil wells, mineral oils may get mixed with the soil. Other than that, soil contamination may also occur through many other methods like while mining, disposing of the industrial wastes, etc. Mineral oil and ores of heavy metals are not at all environment friendly; they can contaminate soil once they get mixed with it. The mineral oil can get mixed with the soil in different ways like during the time of extraction, due to leakage while transporting it through pipelines, etc. It increases the concentration of carbon dioxide and hydrocarbons in the soil.
Causes of Soil Pollution
Soil pollution may occur due to several reasons. Some of these reasons are discussed below.
Extraction of Minerals: At the time of extraction of minerals from the mines, the ores get mixed with the local soil and degrades its condition. Several toxic elements associated with the minerals also cause contamination leading to soil pollution. Sometimes untreated minerals are dumped into the soil without taking proper measures.
Extraction of Mineral Oil: Mineral oil can spill and get mixed with the soil during the extraction process. Upon getting mixed, it increases the carbon dioxide concentration of the soil resulting in the rise of temperature. Leakage in the pipeline can also cause soil contamination.
Industrial Waste: Untreated wastes released from the factories get mixed with the soil causing soil pollution. It is in fact the main culprit in the entire scene.
Agricultural Waste: The use of chemicals in agricultural land is increasing at an alarming rate. This is also reducing the soil quality to a significant extent.
Human Waste: Improper disposal of household waste including plastic goes through the sewer system and ends up in either landfills or soil.
Deforestation: This has an indirect effect on soil quality degradation. Random cutting down of trees or burning causes soil erosion. As a result, vegetation is not possible in the barren land, which over time, reduces the soil quality.
Acid rain (rain mixed with sulphur dioxide or nitrous oxide) can also negatively impact soil quality by changing its character and dissolving important nutrients.
Soil Contamination with Mineral Oil
Most of the oil fields of the world are situated near the deltas, wetlands, etc. During the extraction of the mineral oil from these oil fields, large-scale damage is caused in the local ecosystem. Oil gets spilt during extraction and gets mixed with the nearby soil and water bodies. Resultantly, the concentration of hydrocarbon in the soil increases manifold. Gradually, the average temperature of the marshy land or wetland rises. The same happens when groundwater gets contaminated with mineral oil.
Mineral oil spillage also affects the phosphorous concentration of the soil. The amount of phosphorus decreases while the pH level increases turning the soil excessively basic in nature. Over time, the land is rendered unsuitable for agriculture.
Contamination of soil with mineral oil and petroleum hydrocarbons adversely affect the local flora and fauna. Animal and human health is at great risk due to it.
Following are precisely the three main ways how mineral oil soil pollution takes place:
Spillage during Oil Extraction: Oil spills and get mixed with the soil at the time of extraction from wells.
Due to leakage: Mineral oil may leak through the pipelines while being transported from the field to the other places. It then gets mixed with the soil causing soil pollution.
Waste Disposal: Waste generated during mineral oil extraction when disposed of without proper treatment leads to soil pollution.
Soil Contamination with Minerals
Not only crude oil or untreated mineral oil but minerals with associated impurities also cause an alarming level of soil pollution. Mining changes the surrounding landscape by causing soil erosion. Chemicals and wash-offs from the ores change the structure of the soil. Then, there are the windblown dust particles and soots. All these adversely affect the surrounding land resulting in the significant loss of flora and fauna. The biodiversity is lost; there is widespread ecological imbalance; human health too is hugely jeopardized.
Effects of Mineral Oil Soil Pollution
The addition of foreign elements (read mineral oil and associated impurities) in the soil changes its nature and composition. Other effects of mineral oil soil pollution are as follows:
Soil Degradation: Soil pollution leads to the degradation of its quality and reduces its water holding capacity.
An increased Concentration of CO2: When mineral oil gets mixed with the soil it increases the amount of carbon dioxide and hydrocarbons in the soil, which in turn, cause an overall rise in the soil temperature and that of the surrounding land.
Heavy Surface Runoff: As the functioning ability of the soil reduces it cannot hold water any further. This is also because oil is insoluble in water. As a result, the surface runoff increases and the filtering for groundwater level decreases.
Reduces the Amount of Soil Phosphorous: Mineral oil contamination reduces the concentration of phosphorous in the soil. Phosphorous is very important for plant growth. In the absence of the useful mineral in adequate quantity, the soil loses its fertility over time.
Affects Soil Ecosystem: With mineral oil seeping into the inner layers of soil the pores get clogged. Aeration is hampered. Oxygen supply gets reduced. Plants, animals and microbes thriving in the soil cannot breathe anymore. They die. In other words, the soil ecosystem gets totally disturbed.
Adverse Effect on Human Health: Mineral oil soil pollution can cause neuromuscular blockages in humans. Other symptoms like prolonged depression, fatigue, nausea, headache, irritation in the eyes, and skin rashes may also appear in people living in the surrounding areas.
How to Prevent Mineral Oil Soil Pollution?
Utmost care must be taken while extracting mineral oil from the oil fields. Also, the following measures should be adopted to reduce the harmful effects of soil pollution from any accidental spill:
Removal of the Contaminated Soil: The contaminated soil must be excavated from its place so that the adjoining places do not get affected. The place from where the soil has been removed can be used for landfill (under proper monitoring). The soil removed can be used for paving purpose.
Calamagrostis angustifolia plant helps in the decomposition of the oil present in the soil.
Growing more and more plants in the mineral oil affected area can reduce further soil degradation and soil erosion.
Mineral oil soil pollution is not viewed with as much importance as other types of environmental pollution. But it can be more deleterious that one can ever think of. Mineral oil is not 100 percent biodegradable; neither it is a renewable resource. So, care should be taken to prevent it from happening for the greater good of society and the planet.
FAQs on Effects of Mineral Oil Soil Pollution: Causes, Impacts, and Solutions
1. What is meant by mineral oil soil pollution, and why is it a significant environmental concern?
Mineral oil soil pollution refers to the contamination of soil with hydrocarbons derived from crude oil or its refined products. It is a major environmental concern because mineral oil is toxic to most life forms and is highly persistent. It severely degrades soil quality, making it unfit for agriculture, disrupts natural ecosystems, and can leach into groundwater, posing a widespread threat to environmental and human health.
2. What are the common sources that lead to mineral oil contamination in soil?
The primary sources of mineral oil contamination in soil are typically related to human activities involving the extraction, transport, and use of petroleum products. Common examples include:
Accidental oil spills during transportation via pipelines, tankers, or trucks.
Leaks from underground storage tanks at petrol stations or industrial sites.
Improper disposal of used motor oil and industrial lubricants.
Discharge of effluents from oil refineries and petrochemical industries.
3. How does mineral oil contamination physically and chemically alter the soil?
Mineral oil drastically alters both the physical and chemical properties of soil. Physically, it clogs soil pores, which reduces aeration and water infiltration, leading to waterlogged conditions. Chemically, it increases the soil's carbon and hydrocarbon concentration, often raising the pH and creating a toxic environment that reduces the availability of essential nutrients like phosphorus for plants.
4. What is the direct impact of mineral oil pollution on plant growth?
The direct impact on plant growth is severe. The oil forms a suffocating layer on the soil surface and around plant roots, which blocks the uptake of water and nutrients. This physical barrier, combined with the chemical toxicity of hydrocarbons, inhibits seed germination, stunts root development, and can ultimately lead to the death of plants in the contaminated area.
5. How does mineral oil pollution affect the microorganisms that are essential for soil health?
Mineral oil pollution is highly detrimental to soil microorganisms. The hydrocarbons are toxic to many beneficial bacteria and fungi responsible for nutrient cycling and decomposition. This disrupts critical processes like nitrogen fixation and the breakdown of organic matter, leading to a sharp decline in soil fertility. The overall biodiversity of the soil's microbial community is significantly reduced, crippling the soil's natural regenerative capacity.
6. Why is mineral oil pollution considered more persistent and difficult to clean up than pollution from organic wastes?
Mineral oil pollution is more persistent because its primary components are complex, long-chain hydrocarbons that are hydrophobic (water-repellent) and not easily biodegradable. Unlike organic waste (e.g., agricultural residue), which is readily broken down by a wide range of common soil microbes, the complex molecules in mineral oil can only be degraded by a few specialized microorganisms, making the natural decomposition process extremely slow, often taking decades.
7. Can soil naturally recover from mineral oil contamination, and how long does it take?
While some natural recovery is possible, it is an exceptionally slow process. Certain microbes can biodegrade the lighter, simpler hydrocarbon molecules over time. However, the heavier, more complex compounds like asphaltenes and resins can persist in the soil for many years or even decades. Without intervention, the soil may remain infertile and toxic for a very long time, as its water-retaining capacity and nutrient content are severely compromised.
8. What is bioremediation and how is this concept applied to treat oil-polluted soil?
Bioremediation is an environmental technology that uses living organisms, primarily microorganisms, to break down or neutralize pollutants. For oil-polluted soil, this involves introducing specific, naturally occurring oil-degrading bacteria to the contaminated site (bioaugmentation) or stimulating the native microbial populations by adding nutrients and oxygen (biostimulation). These microbes use the hydrocarbons as a source of carbon and energy, converting them into less harmful substances like carbon dioxide and water.
