Land Pollution: Facts About Soil Disturbance, Defilement and Degradation

Environmental Science, Environment
Land Pollution: Facts About Soil Disturbance, Defilement and Degradation
Page content

The Impact of Badly Polluted Lands

Land pollution is a complex environmental problem. Harms from it include the visible waste and degradation of the Earth’s surface, which makes soil unsuitable for redevelopment or agricultural purposes, and complications in the soil structure, which can influence the chemical properties and biological activities in a particular landform. The resulting soil disturbance is capable of releasing hazardous substances into the environment by way of groundwater contamination or harmful air emissions.

The difficulty presented by soil pollution problems is that they exist even if a vast part of agricultural land yields crops. The toxicity becomes evident as humans eat farm produce that is heavily tainted with metal, resulting in food poisoning. Moreover, it can have long-term effects on the human body of which can take decades before surfacing as a cancerous disease.

The Problem in China’s Farmlands

800px-Kunming Industry

At present, facts and figures about China’s land pollution remain unconfirmed, but reports have it that numerous rice fields in eleven of the country’s provinces are badly polluted with cadmium. The local government of Xinqiao is said to have passed out compensations of polluted rice for the past 20 years. In 2006, nearly 150 people were diagnosed as suffering from chronic-cadmium poisoning in that village, while a great majority of those medically-tested were found to have lower bone density and bone-softening in different degrees.

Currently, researchers at the “Chinese Academy of Science’s Institute of Geographic Sciences and Natural Resources Environmental Restoration Centre” are investigating into the extent of soil pollution caused by heavy metal, which is estimated at about one-fifth of China’s arable lands.

Other heavy-metals that have defiled China’s farmlands include, copper, zinc compounds, lead, arsenic and methyl mercury. Chinese scholars are saddened by the fact that these problems receive very little attention from their government, and that even the sale of cadmium-tainted rice has not been banned.

Farmers, particularly those coming from the poorer sectors, knowingly or unknowingly continue growing and selling the metal-tainted crops. Even villagers in the know cannot afford to buy better crops leaving them to simply accede with what the land yields.

It can be said, however, that through the support of the Ministry of Science and Technology and the Chinese Academy of Science, several Chinese scientists and researchers have come up with technologies to abate the pollution-effects of metal-contaminated soil on rice crops. Still, lack of local government support as far as implementations of the abatement technologies are concerned, has rendered such initiatives as ineffective.

Ironically, China has more than 50 environmental pollution regulations yet the country remains to be at the forefront in all types of contamination problems, including air pollution. Scholars cannot help but compare their country’s pollution problems with that of the U.S. and other western counterparts. Most western countries have promulgated fewer laws but have successfully managed to keep the damages under control. The enforcement of laws that require business entities to assume social and environmental responsibilities are cited as significant contributing factors.

In contrast, one of the major sources of heavy metals that have polluted many of China’s farmlands is the Xiawan Industrial Zone. Chinese researchers believe that information about land pollution is merely being used by business entities as their excuse for repurposing the land or for relocating to other areas.

What are Brownfields and National Priority List Sites?

336px-Waukegan harbor superfund.svg

In the U.S., an abandoned piece of land due to real or perceived contamination emanating from toxic chemicals, illegally dumped garbage or debris from dilapidated structures, like broken glass, rotting wood, and corroded pipes, is constituted as polluted. The Environmental Protection Agency (EPA) estimates that there are more than 450,000 polluted sites like these existing in the U.S.

They are considered as unfit for further use, particularly if there are existing underground storage tanks that were previously used for industrial or commercial purposes. Steel tanks are perceived to be dangerous since they corrode and leak residue of hazardous substances like petroleum and chemicals. Although invisible, the toxins are capable of causing harm to the community and its residents.

Nonetheless, the local cities or states, in which these polluted lands are located, may receive federal or state funding from the government via the EPA’s “Brownfields Program”. Should the polluted land meet the EPA’s criteria and eligibility requirements, it becomes officially known as a “brownfield” and receives funding for clean-up, rehabilitation and redevelopment.

The objective of the clean-up program is to prevent hazardous elements released by underground storage tanks, and by the accumulation of debris and other forms of wastes from causing further damage to the environment and residents.

However, if a site is known to release hazardous contaminants that threaten the environment and human health, it is included in the EPA’s National Priorities List (NPL). Polluted lands included on the list are subject to EPA’s Hazard Ranking System, to determine which of the sites require further investigation that warrant immediate remedial actions.

There are three major criteria by which these sites become eligible for federal funding under the “Superfunds” NPL remedial program:

(1) A recommendation to relocate the residents is issued by the Agency for Toxic Substances and Disease Registry, by way of a health advisory.

(2) The polluted site is ascertained to be a major threat to public health.

(3) The EPA takes into consideration the cost-efficiency of placing the site under remedial actions over the use of emergency responses to remove the source of hazardous substances.

As of April 2011, there are 1290 polluted lands included under the NPL final listing. The land on the list was formerly utilized as:

  • metal foundries,
  • landfills,
  • mining sites,
  • golf-courses,
  • quarries,
  • dry-cleaning establishments, and,
  • industrial sites engaged in the manufacture of pesticides, tires, paper, chemicals, electronics, machineries, ceramics, asbestos, solvents and wood treatments.
  • It also includes sites whose aquifers and groundwater sources have been proven to be contaminated.

Groundwater Contamination and Wetlands Degradation in the US

800px-Runoff of soil & fertilizer

Applications of intensive agricultural techniques, which involve the continuous overuse of fertilizers in any form, have been proven to cause salinity in soil quality due to an imbalance in the soil’s nutrient contents. Accordingly, more than a million hectares of agricultural land have become unfit for the growth and production of agricultural crops.

In addition, the recent “National Water Quality Inventory Reports” have cited certain agricultural lands as the major causes of non-point sources (NPS) of pollution to the environment, based on the following factors:

  • Indiscriminate application of pesticides and fertilizers.

  • Mismanagement of planting and harvesting activities and other agricultural procedures, like irrigation and maintenance of animal facilities. As a non-point source (NPS) of pollution, pollutants like heavy metals, phosphorus and various pathogens are attached to the soil particle and are carried off by winds and water run-offs to nearby bodies of water.

  • Excessive applications of potassium, nitrogen and phosphorus, in the form of chemical fertilizers, sewage sludge, manure, irrigation water or organic substances like legumes and crop residues, were found to have contributed high concentrations of nitrate to the sources of drinking water used for human consumption.

Nevertheless, numerous government programs are in place to address the prevention and control of NPS sites granted under the Clean Water Act. Funds are granted under the administration of the U.S. Department of Agriculture and state-funded programs that provide cost-sharing and technical assistance, as well as economic incentives to clean the land.

Quick Summary

Based on the facts and figures presented above, a quick rundown of major land pollution causes which impact the environment and human health are:

(1) Industrial wastes carrying heavy metal sediments and chemical residues that are carelessly dumped into the ground and nearby bodies of water.

(2) Abandoned or idle land illegally used as landfills or garbage dumps, or where the debris of dilapidated structures comprise metals, chemicals, plastic and other forms of corrosive and rotting wastes that tend to release hazardous compounds into the ground and into the atmosphere.

(3) Underground storage tanks of abandoned petroleum establishments and industrial companies, wherein the steel tanks are left to corrode and leak-out the residues under the surface soil.

(4) Overuse of agricultural soil-additives for intensive farming activities, as this tends to cause soil salinity and imbalance in the soil’s nutrient composition.

(5) Mismanagement of agricultural activities, which does not take into consideration the pathogens, metal residues and phosphorus attached as pollutants to the soil particles, and subsequently carried off by the wind and by water run-offs.

(6) Use of irrigated water coming from polluted streams and rivers.

All these have contributed to the disturbance, defilement and degradation, not only of the Earth’s land surface but also of the soil structure and the composition of the layers underneath.

References/Image Credits:

References:

Image Credits: