The Main Causes of Land Pollution
Have you ever thought about what will the world look like in 100 years? Will it look better than it looks today? Or worse? The truth is that nobody can see the future, however with the ever increasing human population, there is one major problem that has been getting worse over time: land pollution.
Air and water pollution are often more discernible than soil pollution and evoke a more visceral response, a revulsion against what can be seen. Land pollution is an equally serious problem and often also contributes to water pollution through percolating down to the water tables or erosion runoff into open waters.
What is land pollution?
Land pollution is defined as a degradation or even destruction of the earth’s surface and soil as a result of human activities.
Sources of soil pollution can be direct, for example, from dumping toxic chemicals directly on to a site, or indirect, for example where toxic chemicals leach through the soil from particulates that have settled from air pollution from a nearby lead smelter .
It can also simply be degradation from transforming the land by clearing it so that beneficial organisms can no longer provide services supporting growth and protect it from further erosion.
The expansion of housing developments, businesses, industry, infrastructure and agriculture all necessitated by an unprecedented population explosion over recent years accounts for humans modifying over 50 percent of the earth’s topsoil .
This human activity appears more than a little reckless when considering that it takes 500 years to naturally produce 2.5 cm topsoil in ideal conditions, absent of ecological changes .
Effects of land pollution on the environment
Land pollution, whether it is a barren space where nothing can grow but a few weeds or a site that harbors garbage and debris, like old tires, gas cans and plastic bags is an aesthetic drain.
Studies consistently show the health benefits of enjoying nature at its finest, with its lush growth, clean air and water renewing world-weary urbanites . The health-promoting practice of drinking in nature in Japan is a cornerstone of healing therapies in Japan and South Korea, where it is known as “forest bathing” .
Conversely, while not documented, no one would dispute that the effect of seeing barren or polluted land is depressing. But there are even more serious problems how land pollution affects the environment.
This has further consequences for us as part of the web of life. The web has been broken when the biodiversity that enables life has been destroyed. Where there are no plants, there is no oxygen-generating mechanism (photosynthesis), no food or habitat for wildlife, amphibians, insects, and probably few, if any microorganisms to aerate, detoxify and regenerate the soil.
Soil that is filled with toxic chemicals will not sustain life and poses a health risk to children who might play there.
Prior to being banned in 1977 due to its adverse effects on humans and wildlife and long-term persistence in the environment, PCBs or polychlorinated biphenyls were widely used in industrial coatings and insulation materials for transformers as well as hydraulic fluids, fluorescent lights and various consumer goods. They were disposed of not only in landfills, but through illegal dumping and by burning.
The ash and particles from burning fell to the earth and were absorbed by the soil. Today, almost all soil has at least small amounts of PCB .
Children playing in areas of PCBs can absorb the toxins through their skin. And studies support evidence of their carcinogenic effects as well as various other negative immune, reproductive, neurological and endocrine effects .
Toxic chemicals can leach into the soil and reach the water table below, often a source of drinking water for the nearby community.
When it rains, a soil without plants to hold it in place will erode and the chemicals it contains on its surface and within the soil itself will runoff and pollute rivers and streams the water empties into, or bays and oceans, either directly or via tributaries.
The toxic chemicals can lodge in the ground sediment of the stream, adversely affecting the aquatic life that sustains itself by sheltering and feeding there. The toxic chemicals absorbed via ingestion or skin absorption make their way up the food chain as they are stored in the tissue of the marine life and magnified as larger fish eat more of the tinier prey, so that the meal can be quite toxic by the time the fish makes it to our dinner plate.
It is not just direct pollution of toxic chemicals that can cause these problems. Nor is the problem confined to abandoned lots or illegal dumpsites.
What are the causes of land pollution?
Land pollution is a major problem around the world and is caused by a variety of factors. Some of main causes of soil pollution include deforestation and consequent erosion, agriculture, industry, mining, landfills and illegal dumping of waste as well as urbanization and construction .
Let’s have a look at these activities in detail to see how exactly pollution of land resources happens when they take place.
In the Amazon rain forest in Brazil, an area the size of a football field is clear-cut by loggers every second . The removal of plant cover not only eliminates wildlife habitats and food for wildlife, but it also degrades the soil by leaving it barren and without the roots of plants to hold it in place, vulnerable to erosion.
Obviously, a rain forest gets a lot of rain, heavy rain and without a forest canopy to buffer the downpours and without ground cover to hold the soil intact, the rich soil of the forest floor is easily washed away. Along with the topsoil go the nutrients necessary to regenerate growth.
It is estimated that eighty percent of land animals and plants live in forests. Removal of even a portion of the canopy changes the environment of the forest as the canopy blocks the harmful sunlight and keeps in heat at night. Many species cannot adapt to these severe changes in temperature and many species do not survive the destruction of their habitats .
Loggers are not the only ones responsible for the rapid deforestation of the earth. Land developers capitalizing on urban sprawl cut down forests, as does the agricultural industry in order to increase the amount of land for growing crops.
In fact, agriculture has been found to be the direct cause if 80 percent of deforestation worldwide . Much of this agricultural land is required to grow crops for animal feed, primarily cattle for the beef industry. The land is also used for cattle grazing .
The world population increase and increased demand for a food supply is causing forests and grasslands to be converted to farmland. Natural vegetation has deep roots that hold the soil in its place. Many of the replacement plants, like cotton, coffee, wheat and soybeans do not have deep roots and allow soil erosion. This means that flooding is worsened as the land no longer has the ability to absorb excess rainfall . It also allows for easy runoff of fertilizers and other applied chemicals.
Farmers routinely apply highly toxic fertilizers, pesticides, fungicides, herbicides and insecticides directly on to the crops and land. What is not sprayed or directly drift on to the land, enters the soil through the plant’s roots and via the carcasses of the target insects and organisms and debris of the dead weeds. The contamination destroys the healthy organisms responsible for generating new vegetative growth.
It can also renter the soil through rainwater.
The change in chemical composition of streams and rivers from this chemical runoff upsets the natural balance of life causing other, often foreseeable but unanticipated problems. The damage wrought from fertilizer runoff from agriculture is well-documented. It brings excess nitrogen to the water environment, creates algal blooms and consequent dead zones in the water where nothing can live.
A dead zone at the mouth of the Mississippi River from fertilizer runoff primarily from corn fields along its banks, covers more than 7700 square miles (20,000 sq km) in the Gulf of Mexico during the summer months. The runoff is not only continuing, unabated, but is expected to increase as the demand for corn to feed cattle and as a biofuel increases .
The herbicide atrazine mentioned above has been found to cause changes in the reproductive systems in frogs, turning male frogs female..
The high cost of filtering agricultural chemicals in wastewater treatment plants is ultimately absorbed by the drinking water consumer and one must question whether that is a fair allocation of expenses or whether the agriculture specialist responsible for the pollution should bear the cost, resulting in a better likelihood of more responsible decision-making.
The US Department of Agriculture sets the cost of wastewater treatment to remove these nitrates at $1.7 billion a year. Costs of treating well water, in those situations where the contamination has been discovered by neighbors was $1.12 billion between 1991 and 2004. And the health costs to treat consequent respiratory diseases as of 2016 were running $23.10 for each kilogram of nitrogen used in the US .
Overgrazing also causes loss of natural vegetation and compaction of the soil, disrupting the balance of natural microorganisms and often promoting the growth of harmful bacteria as well as contributing to the problems caused by erosion .
Industrial activities often release toxic and material wastes onto the land or into the atmosphere where they settle onto the land. While most developed countries now regulate land dumping and emissions, the regulations balance the costs to industry and do not necessarily adequately safeguard the integrity of our biosphere or more specifically, human health.
Too, many developing countries have little or no enforced regulation.
For example, although cassava is the third most consumed carbohydrate in the world, the practice of dumping its toxic byproducts, that is, hazardous solid and liquid residues directly onto the land, continues in Nigeria today.
A recent study of the effects on the soil of dumping cassava showed many deleterious effects to the previously arable land. The heavy metals bring about harmful changes in the microbiological, mineral and physiochemical composition of soils around the mills .
Forty percent of the world’s mines are strip mines. This is where the earth is either scraped or blasted to get to the mineral seams. The balance of mining is done underground, where pillars support the earth while work is performed underground and at the end, removed or simply left to collapse.
Strip mines obviously remove the topsoil and contribute to erosion. In many developed countries, regulations now require land reclamation when the project is over.
A 2004 study showed that China’s overall land reclamation rate to its strip mining operations was only about ten to twelve percent. And a problem when the reclamation is attempted is that the land has become so degraded it often cannot support newly seeded growth. Studies in US western states showed success rates of new seedlings taking purchase between ten and thirty percent .
Underground mining brings a lot of waste earth and rocks to the surface where it is left. This waste often becomes toxic when exposed to air and water.
Another effect on land pollution are coal fires. Underground coal fires, a significant problem in many countries can burn for centuries, emitting toxic gases, among them mercury, arsenic, fluorine and selenium, as well as emitting fly ash through its vents and fissures which then settle on the land.
Landfills and waste
The construction of landfills is generally overseen by a governmental agency responsible for solid waste disposal and involve compliance with regulations to safeguard the leaching of their contents into the soil. However, the clay or plastic liners often fail over time or of course, when compromised by construction breaking through them.
One of the most famous environmental violations in the United States, Love Canal, though hardly an isolated incident, concerned a breached landfill containing toxic waste that caused miscarriages, nervous disorders, cancers and an unusually high number of human birth defects and deformities before being discovered. The Love Canal incident was a major impetus for passage of the Superfund Act, a law imposing strict liability, that is responsibility that cannot be bargained away from injury and damages arising from exposure to the spilled toxic contents.
Love Canal was an abandoned canal project which became a landfill for dumping hazardous waste in the 1950s. It was later conveyed by the chemical company owners to the local school district for $1 with full disclosure of the chemicals then buried underground, in consideration for a release of liability in perpetuity.
The school board built a school and playground above the dump and sold surrounding property to private developers and homeowners. Heavy rains and construction breaching the landfill clay container walls caused release of drums of toxic chemicals the children played in and toxic chemicals leaching into the water table, nearby yards and basements and sewer system, the latter recycling through the treatment plants for drinking water.
Upon public outcry of the smelly, oily water in their yards and basements, local journalists began investigating. Their investigations revealed a cocktail of inorganic toxic chemicals including benzene, chloroform, toluene, dioxin and PCBs .
Landfill liners are not foolproof and the liquid that leaches from them is toxic. Liners are generally simply thick plastic and deteriorate over time. Even the EPA has concluded that any liner will begin to leak eventually . The liquid that leaks from landfills is known as leachate, often a. highly toxic liquid containing many chemicals resistant to ordinary wastewater treatment.
Landfill regulations prescribe actions that must be taken to remove leachate from the landfills during its years of operation and upon closure, but the reality is that while it may be years before the leachate gets into the groundwater, eventually it will.
Presently the United States is facing a very big problem at the Hanford Nuclear Waste facility. It appears that the double-shelled tanks storing radioactive waste have sprung leaks. Leaching radioactive cancer-causing isotopes into the soil, only five miles from the rushing Columbia River .
Urbanization contributes to land degradation in a number of ways, including the negative impact of construction on soil, the displacement and destruction of animal and species habitat and the greater demand for waste disposal, generally meaning larger landfills removed from the city.
An urban planner looked at yet other needs the land provides people and estimated in 1996 that the land required to feed the population of London, supply their timber products and reabsorb their CO2 emissions by areas with growing vegetation was 125 times the size of the city .
That being said, the same number of people will eat the same amount of food wherever they live and require the same amount of other resources, maybe even less when it comes to housing and given the more plentiful options for public transportation, it may well be that their CO2 emissions are lower and their environmental footprint smaller.
A drive down any road reveals that humans contribute to land degradation by littering. Not as obvious are the oils, paints and other hazardous household wastes disposed of along roads because they are not accepted by most household waste collectors.
One of the favored dumping areas is highway construction sites. Because the materials are buried and not visible, a recent investigation to find hazardous waste dumps looked at the effect of an increase in the number of roads on specific health outcomes of people living nearby, in particular: infant mortality, hemoglobin level and severe anemia of children under five years old .
Land pollution is also caused by waste that is washed ashore from boats, oil rigs, and sewage outlets, referred to as marine trash .
Ways to reduce land pollution
Economic incentives need to be put in place for farmers at the frontier of forests so that they intensify their production without expanding their land by cutting down the forests . Governments could put money into researching higher yielding varieties of tropical crops and then develop policies like subsidized seeds to encourage their use.
The farmers could be educated by local extension agencies in sustainable practices like conservation tillage, cover crops, crop rotation and adding crop residuals to increase the fertility of their soil instead of fertilizers that cause greenhouse gas emissions, and land, water and air pollution.
The inhabitants of the forests could be taught how to stop pollution by learning about other methods of earning an income that do not jeopardize the forest habitat, like ecotourism in its purest sense or small-scale businesses harvesting sustainable amounts of the forest’s resources and replacing them.
Insisting on organic food would be a very big start to reducing the adverse effects of agriculture on land. Requiring sustainable practices that help land regenerate and reestablish a community of beneficial organisms between crops would be helpful. Zoning requirements mandating havens of biological diversity at the edges of agricultural land, once the toxic chemicals are no longer in the equation of course, would work to promote the natural balance of life, where crickets and frogs and pollinators can all help make the land more productive.
Populations eating less beef would go a long way to reducing the need for animal feed and land for grazing.
We must be diligent in insuring that tough laws are enacted that require the very best pollution control technologies imaginable, pass strict pollution emission standards and make sure they are enforced. This applies too to regulations governing mining and industrial waste and disposal of solid and hazardous waste.
The world’s population needs to be educated in the health hazards of these pollutants to create an awareness of what is happening and the importance of being involved. Only by possessing adequate knowledge we can focus on the necessary prevention of land and global pollution overall.
A possibility is bringing religious leaders into the picture to help educate their followers. Very often there is a dichotomy on environmental issues as the theory of evolution invites an easy divisiveness between science and religion, but that gap should be bridged as we reach toward a common solution.
For humans to cause species to become extinct and to destroy the biological diversity of God’s creation, for humans to degrade the integrity of the earth by causing changes in its climate, by stripping the earth of its natural forests, or destroying its wetlands, for humans to contaminate the earth’s waters, its land, its air and its life with poisonous substances, these are sins.— Patriarch Bartholomew I, spiritual leader of 300,000,000 Orthodox Christians
In spirit, on that we can all agree.
 47 Fed.Reg. (July 26, 1982), at pp. 32284-32285.
 The Gaia Atlas of Cities, Girardet, Herbert, Gaia Books, Ltd, London, 1996, p.24.