What is Soil Contamination?

Chemicals from factories polluting the soil and groundwater.
Chemicals from factories polluting the soil and groundwater.

Soil contamination is part of soil degradation caused by human activities or changes to the natural soil environment. The soil is considered contaminated when the concentration of chemicals, nutrients, or other elements in the ground is higher than the standard concentration. Soil contamination may harm living organisms in the soil, resulting in soil pollution. Soil contamination may affect the growth of plants that depend on it. The soil contaminants may also be infiltrated into groundwater and cause pollution which will place the water users at risk.

Causes Of Soil Contamination

Several factors may lead to soil contamination. Human activities such as oil drilling, mining, extensive farming, and waste disposal are all major causes. The most common chemicals that easily contaminate soil include pesticides, petroleum, lead, and other heavy metals. Deposition of coal ash used in industrial heating processes is a common source of contamination in areas that are highly industrialized. Although treated sewage can be used as fertilizer, it contains contaminants such as organisms and heavy metal which are harmful to the soil. Pesticides benefit farmers and other users in controlling pests which are likely to reduce yield. However, these pesticides may contain toxic substances which may affect human and other important organisms in the soil. Herbicides such as trinitrotoluene and paraquat contain impurities which are very toxic and may rapidly degrade the soil. The disposal of munitions and carelessness in the part of the manufacturers of munitions may lead to soil contamination for an extended period.

Health Effects Of Soil Contamination

Contaminated soil has direct effects on human health through direct contact or my inhaling the contaminated soil which has evaporated. The Greater threat is posed by the contaminated soil if it infiltrates into the groundwater aquifers. Health consequences from the exposure to soil contamination depend on the degree of pollution and the type of pollutant and the vulnerability of the exposed population. Exposure to metals such as lead and chromium may cause congenital disorders and other chronic health conditions. Exposure to benzene at high concentration may result in leukemia while mercury may lead to incidences of kidney damages and other irreversible conditions. Direct contact with the soil contaminants or ingestion of the contaminant may lead to direct death.

Ecosystem Effects Of Soil Contamination

Soil contaminants have severe consequences on the ecosystem. The contaminants may affect the soil chemistry causing an alteration of metabolism of microorganisms resident in a given environment. The modification may lead to the eradication of food chain which may have major consequences on predators or consumer species. The contaminants may also alter plant metabolism leading to a reduced yield/low yield may affect the soil conservation since the crops cannot shield the soil from erosion.

Soil Cleanup Options

A contaminated soil may be remedied by digging out the contaminated soil for treatment and disposal or containing it to prevent it from spreading to safe soils. The soil contaminants may also be treated using other chemicals.


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