When we talk about pollution, many of us think of only air pollution. Though some of the others also recognize noise pollution and water pollution, very few of us are aware of soil pollution and its extent. This is why the report published by the Food and Agriculture Organization of the United Nations (FAO) and the United Nations Environment Program in 2021 specifically suggested launching a global awareness-raising campaign on soil pollution.
Before we delve into the topic let us first explain what we mean by soil contamination and soil pollution. According to a document published by FAO, soil contamination occurs when the concentration of a chemical or substance is higher than that which would occur naturally but is not necessarily causing harm. The same document tells us that soil pollution refers to the presence of a chemical or substance out of place and/or present at a higher volume than the normal concentration that has adverse effects on any non-targeted organism. Clearly, soil contamination is the preliminary step of soil pollution.
Now, this higher-than-normal concentration can happen because of a plethora of reasons. Barring extremely rare cases when natural phenomenon changes the concentration significantly, most of these reasons are directly or indirectly linked to human activities. The variety of contaminants speaks the volume of the complexity of the problem. Contaminants can range from inorganic heavy metals to asbestos and from organic material such as pesticides to synthetic material such as plastics. For an elaborate list of such contaminants, one can refer to the excellent article on Britannica.
So now we know something about contaminants, but the next question that pops into our mind is, how do they get into the soil? Well, there are quite a number of ways these contaminants can reach the soil and eventually exceed the normal concentration. Though there are regular accidental cases such as leakages from storage or transport vehicles, more often than not many of our day-to-day processes and activities are the causes of soil pollution. Mining activities cause tremendous damage to the soil as they introduce harmful elements. In this regard, it may be startling to many of us to know that rare earth elements are used in a variety of goods, from camera lenses to loudspeakers. The process of mining these rare earth minerals is extremely hazardous and damages the soil and environment to an unimaginable extent.
In agriculture, pesticides and herbicides have been beneficial for the increase of productivity from the land. However, as the law of unintended consequences, there have been massive costs attached to our excessive use of pesticides and herbicides. The research done by Pelosi et. al. shows the extent of the adverse effect of pesticides on earthworms, and other similar research shows the effects on other organisms and the environment as a whole. Even though in most of the developed countries the usage of such substances is heavily regulated now, in the developing world the situation is quite different. Moreover, many of these pesticides are still stored in large quantities and occasional leakages do take place.
Construction activities are another important group of pathways of introduction and accumulation of contaminants in soil. Procurement of building materials, their processing, and release of construction and demolition waste negatively impact both soil and water. Lastly, it is extremely important to note the impact of plastics and synthetic polymers in this context. Plastics persist in the environment for decades and can be partially broken down by mechanical action or weathering. Micro and nano-plastics can be ingested and absorbed by organisms and transferred across the food chain.
Not only the environmental costs but also the economic costs of soil pollution are huge. Decreased crop yields, unsafe food, polluted groundwater, etc. are some of the most prominent examples of the economic costs of soil pollution. For example, it is estimated that soil pollution will lead to a loss of agricultural productivity of between 15 and 25 percent. In China, soil pollution is estimated to cause annual agricultural economic losses worth USD 20 billion due to lost productivity and food contamination. In the Irish context, a rather unfortunate incident took place in 2008, when a food crisis took place in Ireland. Around 8 percent of all Irish pork products were contaminated with dioxins and dl-PCBs. Some 30,000 tons of pork products were withdrawn from domestic and international markets and subsequently destroyed; about 170,000 pigs and 5,700 cattle were slaughtered. This incident cost the Irish exchequer more than 120 million euros along with loss of consumer confidence. An interesting diagram on http://www.eea.europa.eu summarizes the economic effects.
The final question that remains is, how do we prevent this? The answer is not simple and as with other pollutions, it needs effort from us all. Whereas government agencies across the world need to be more strict in enforcing the rules and enterprises need to follow them, we as individuals must play our part as well. FAO’s suggestion in this regard is very intuitive. For us individuals, the focus must be more on reducing and reusing. Proper disposal of items is extremely important. If each of us changes personal habits just a little, the collective change will be humongous, and it will be for the benefit of us all.
- FAO, Global Assessment of Soil Pollution, 2021.
- N. Rodríguez-Eugenio, M. McLaughlin, and D. Pennock, “Soil Pollution: a hidden reality”, “FAO”, pp. 142, 2018.
- “Soil pollution,” Encyclopædia Britannica. [Online]. Available: https://www.britannica.com/science/soil/Soil-pollution. [Accessed: 30-Dec-2021].
- “Soil contamination,” Wikipedia, 18-Dec-2021. [Online]. Available: https://en.wikipedia.org/wiki/Soil_contamination. [Accessed: 30-Dec-2021].
- “Boom in mining rare earths poses mounting toxic risks,” Yale E360. [Online]. Available: https://e360.yale.edu/features/boom_in_mining_rare_earths_poses_mounting_toxic_risks. [Accessed: 30-Dec-2021].
- “Unintended consequences,” Wikipedia, 29-Dec-2021. [Online]. Available: https://en.wikipedia.org/wiki/Unintended_consequences. [Accessed: 30-Dec-2021].
- C. Pelosi, S. Barot, Y. Capowiez, M. Hedde, and F. Vandenbulcke, “Pesticides and earthworms. A Review,” Agronomy for Sustainable Development, vol. 34, no. 1, pp. 199–228, 2013.
- S. Sandil and R. Kumar, “Soil contamination from construction projects,” Ecological and Health Effects of Building Materials, pp. 205–244, 2021.
- “Land and soil pollution – widespread, harmful and growing,” European Environment Agency, 28-Sep-2021. [Online]. Available: https://www.eea.europa.eu/signals/signals-2020/articles/land-and-soil-pollution. [Accessed: 30-Dec-2021].
- “Chapter 4. environmental, health and socio-economic impacts of soil pollution,” FAO. [Online]. Available: https://www.fao.org/3/cb4894en/online/src/html/chapter-04-4.html. [Accessed: 30-Dec-2021].
- C. Tlustos, “The Dioxin Contamination Incident in Ireland 2008,” 2009.
- I. Marnane, “Comprehensive Environmental Review following the pork PCB/dioxin contamination incident in Ireland,” Journal of Environmental Monitoring, vol. 14, no. 10, p. 2551, 2012.
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