Effects of Mineral Oil Soil Pollution

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. 

FAQ (Frequently Asked Questions)

1. How Does Soil Get Contaminated With Mineral Oil?

Ans. While extracting mineral oil from the oil fields, an oil spill can occur and that crude oil can get mixed with the soil causing soil pollution. The chemicals in the mineral oil increase the soil Ph level and reduce the phosphorous concentration of the soil. The basic composition of the soil hence gets changed and the overall temperature rises. Pore spaces get clogged thereby reducing soil permeability and aeration. Worse, mineral oil increases the carbon and hydrocarbon concentrations of the soil thereby affecting the underground flora and fauna. 

2. Does Oil at All Decompose?

Ans. Unfortunately, a large spill of crude oil might not decompose for years. It has been proved that microbes can biodegrade light crude oil up to 90%. But the large and the more complex oil molecules like the ones used to manufacture road asphalt cannot be properly biodegraded.

3. How Many Years Does Soil Take to Decompose Mineral Oil?

Ans. Soil takes nearly one year to decompose the oil present in it. However, within this time, its fertility gets severely reduced and the topsoil experiences heavy erosion as the water-retaining capacity of the soil decreases significantly.