Environment

Here are some sources of soil pollution you may not know

Did you know testing of nuclear weapons and remnants of war have polluted our soil for centuries? Find out here

 
By Isha Bajpai
Last Updated: Saturday 12 May 2018

The soil beside roads is easily polluted by either car engines or vehicles splashing water off roads. Credit; Wikimedia CommonsSoil, if polluted, poses a threat to agricultural productivity, food safety and human health and yet, there are many elements contaminating it that people are not much aware of.

A report by the Food and Agriculture Organization (FAO) of the United Nations synthesised all the available scientific research on soil pollution and brought to the fore certain lesser know sources that have been polluting the soil for years now.

Nuclear weapon testing

Atmospheric testing of nuclear weapons and radiological events like the Chernobyl accident leave behind radionuclides in higher concentrations. “Due to the nuclear fallout after the catastrophic Chernobyl accident, radionuclides will be present in soils for centuries. More than 50 years will be needed to reach a reduction of 50 per cent of the radionuclides,” says the report titled Soil Pollution: A Hidden Reality.

These radionuclides, if deposited in the soil, can be easily absorbed by plants, making them available for further redistribution within the food chain. “After the Fukushima accident, strict monitoring of agricultural products demonstrated a fast decay in radionuclide content in vegetal products, but also discovered that radionuclides remained bioavailable in soils long after initial contamination,” says the report which was released at a global symposium.

While many consider topsoil removal as the recommended solution to limit the damage after a major radioactive accident, it may be not possible for large areas as that generates a huge amount of radioactive waste. As a result, agricultural areas with radionuclides are often abandoned for many years.

Remnants of war

Modern warfare saw non-degradable and chemical weapons affecting soils, not just for years, but for centuries after the conflict had ended. Wartime and test-firing, too, can degrade the soil.

“The First and Second World Wars left Europe with a significant heritage of pollution (land mines, remains of ammunitions and leftover chemicals, radioactive and biological toxic agents), not only in the battlefields but also in sites such as shooting areas, barracks and storage of armaments. This legacy has made the soils in some of these areas unsuitable for any kind of exploitation or service provision,” says the report.

Quoting data from another research, the FOA report said there are approximately 110 million mines and other unexploded ordnance scattered in 64 countries on all continents. These remnants of wars from the early 20th century are still there up until today. “There is little published evidence on this type of contamination, largely because of restrictions placed by governments of many countries on the publication of material related to warfare,” it adds.

Soil near road

Not only the pollutants released from internal combustion engines pollute soil, but also activities like vehicles splashing water off roads during rainy season at a place with poor drainage system. “Activities linked to transportation in and around urban centres constitute one of the main sources of soil pollution. Soils near roads have high levels of heavy metals, polycyclic aromatic hydrocarbons, and other pollutants,” says the FAO report.

Since grazing in roadside soils is also quite common, animals could eat contaminated soil and the plants that are grown in it are also part of the diet of both animals and humans. One more major source of soil pollution linked with transportation is lead contamination of soil from leaded gasoline.

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