Land pollution is the contamination or degradation of land. While most of the land pollution is man-made, there are also natural causes; many of which are exacerbated by human activities.
Manmade Land Pollution
Land pollution comes in many manmade forms such as accidental disasters, Brownfields, waste management and landfills, pesticides and agricultural practices, clear cutting, urban development and energy production. Each has a long-lasting negative impact on the environment, but can be controlled and each has a solution.
The Deepwater Horizon Spill that occurred in 2010 in the Gulf of Mexico in just one example of an extreme accident that killed people and aquatic life. The spill impacted environmental and economical sectors and even reached the shorelines. In 2016 it was reported that loss vegetation due to the oil spill has lead to large-scale shoreline erosion. Even though they are unintentional, the impact of disasters like this has far-reaching consequences.
Brownfields, a Big Pollution Problem
A Brownfield is land that has been abandoned and often contains hazardous pollutants or substances left behind by industries and factories. Brownfields can also be old mines as well as former industrial dump sites. Storm water runoff is a major concern for this type of property since it can create water pollution and spread pollutants and contaminants to other lands as well as water sources.
The EPA's (Environmental Protection Agency) Brownfields Program was created to reclaim these pieces of real estate and through cleanup and redevelopment, make them usable and valuable pieces of properties once more. According to the EPA:
- There are more than 450,000 Brownfields throughout the United States that could benefit through the EPA Brownfields Program.
- Between 1995 to 2017, over 8000 sites with a total of nearly 90,000 acres have enrolled in the program, according to Minnesota Brownfields (pg. 6).
There are environmental, social and economical benefits of cleaning up contaminants from a land, points out Minnesota Brownfields (pg. 7).
- The recycled land encourages the conservation of pristine lands.
- For a community, the reclaimed land brings in more property taxes, attracts more industry into the area, which then creates new jobs.
Mining and extraction of fuels, the energy production process, and waste disposal can all lead to pollution problems.
- EIA-Wells. Risks of spills and contaminates can pollute surrounding land during drilling and transportation of oil, whose effects remain for decades. A broken pipe leaked 100,000 tons of oil in 1994 in Komi, Russia. The oil has hardened and still remains on the land surface, reports Greenpeace.
- Coal mining: Ninety percent of coal that is mined is used for producing electricity in the U.S.; in 2016 alone 728 million tons of coal was used. The mining process requires the displacement of soil and introduces toxic chemicals and other pollutants into the environment. It is also an occupational hazard, with many people getting killed each year notes the Union of Concerned Scientists.
- Natural gas: By 2015, there were 300,000 fracking sites that produced 67% of the gas production in USA. Exploring for natural gas destroys vegetation and the soil structure. Drilling and extraction also levels lands leading to erosion, and disrupts natural plant and animal life. Fracking the new method of gas extraction can pollute the surrounding land due to spillage of extraction fluids, and contaminated wastewater discharge according to Energy Information Administration (EIA).
- Nuclear plants: Mining for huge amounts of uranium can cause considerable dust that is radioactive and lead to gamma radiation, and the sludge produced from the chemical extraction process, if improperly disposed, is hazardous due to 85% of radioactivity as the ore. Seepage of mining waste into deeper layers of the soil and then groundwater are other dangers. Moreover, spent fuel storage is a problem in case of an accident. The accident in Chernobyl resulted in leakage from spent fuel storage areas that is still contaminating land with radioactivity 30 years after the accident.
Waste Management and Landfills
Leachates from solid waste landfills contain pollutants depending on what is disposed. This can vary from heavy metals to organic compounds that impact land and underground water sources. There are also special landfills to hold hazardous materials, according to EPA-Landfills. There were 1956 landfills in the U.S. by 2014 according to Statistica. This problem is compounded by illegally dumped chemicals.
Pesticides and Agricultural Practices
Harmful chemicals used in agriculture collect in the soil and eventually create contaminated land as well as water runoff that finds its way into streams and rivers to other land and eventually the oceans.
- Fertilizers contaminate soil with heavy metals and kill beneficial microflora which in turn affects the soil's fertility and structure, according to FAO. When they are carried away by rainwater runoff, they cause eutrophication in water bodies. One third of the world soil is degraded due to farm chemicals. Fertilizer application has increased four fold since 1960s according to Our World in Data.
- Pesticides can also kill microflora and fungi necessary for minerals' cycling in soil and affect fertility. They also leach into soil and pollute groundwater. Pesticide production that started in the late 1940s now totals 3 million tons per year according to Our World in Data.
Logging and Clear Cutting
Large scale harvesting trees can lead to soil erosion and serious land changes.
- According to World Wildlife Fund (WWF), forests are cut to make way for farms, pastures, settlements, mining, and fuelwood harvesting. Illegal logging for timber affects many forests in the world too.
- In the U.S. in the 1600s, 46% of the land (pg. 5) was covered by forests. By 2016 it was 33.9%. The biggest threat to U.S. forests today is the clearing for urban developments and agriculture.
One of the most overlooked causes of land pollution, are the 1.6 million miles of unpaved roads in the U.S. These roads erode very easily and once the process begins, they deteriorate very quickly. The sediment washes to nearby streams and rivers raising their level, making them flood during rains. This sediment also affects aquatic life that need clear waters. The dust in dry seasons is a problem for neighboring farms and for people who inhale the dust.
Naturally Occurring Land Pollution
A second category of causes are natural processes which can create soil pollution, and these are not easily controlled. Some processes like erosion, floods, forest fires, and storms can be exacerbated by human activities.
Naturally occuring erosion was gradual and did not displace much soil. Rainfall, climate and slope are the natural causes of erosion. However, this natural process' impact is exaggerated due to many human activities, such as grazing and intensive agriculture, which replace forests that hold the soil together. The current erosion levels can lead to severe pollution as sediment finds its way into streams, rivers, and oceans. As the sediment dumps into the oceans, it can upset fragile aquatic eco-systems and marine life.
- Human activities lead to ten times more erosion than natural causes.
- WWF-Erosion notes that half of the topsoil has been lost in the last 150 years due to agriculture.
A raging river swollen by rain or a heavy snow thawing too quickly, are natural causes of flooding notes National Geographic. Floods can cause extensive damage to property, people, and animals.
Large-scale deforestation has led to increased runoff, and climate change has increased the force and volume of floods. In the U.S., increased paved areas prevents percolation of water into the soil, which subsequently swells floods, according to WWF-Floods.
- 1998 was considered a particularly bad year where the Americas, Asia, and Europe were all struck by floods, according to WWF-Floods.
- The U.S. loses 140 people and $6 billion each year due to floods, according to National Geographic.
Lightning strikes can create massive forest fires as easily as one created by a careless camper or passerby. Natural fires are part of many ecosystem dynamics. Past landuse and climate change are making it worse. Fires result in destruction of forests and kill wildlife as well as damage to properties and loss of lives.
- Fluctuating landuse since the 1600s is marked by more or less fires depending on the amount of fuel buildup, according to University of Arizona.
- Due to climate change, the length of the fire season has increased by 20% and area affected has doubled since 35 years according to Smithsonian Magazine.
Natural disasters such as earthquakes, tornadoes, and hurricanes destroy manmade structures, and carry contaminates and hazardous materials into waterways and oceans. These pollutants disrupt the natural order of marine life and aquatic systems.
There is growing evidence that the intensity of hurricanes has increased since the 1970s due to manmade climate change. Intense storms like Hurricane Harvey that occurred once in a 100 years now occur once in 16 years reports the Union of Concerned Scientists.
Many people are surprised to learn that soil can be contaminated from natural elements such as heavy metals that include lead, arsenic, chromium, selenium, and cadmium. These metals are pesent everywhere due to the natural weathering process of rocks which produces soil. These are however usually in low concentrations. Plants growing in healthy soils can accumulate them according to New Hope.
Radon is present naturally in soils and rocks, as a result of uranium decay. From the soil this gas escapes into air and can find its way into water. It is found in high concentration in caves, mines, and water treatment facilities. In the open air its concentration is not high, however indoors its concentration can increase. When inhaled, this radon causes lung cancer. This gas is responsible for 3-14% of lung cancer in the world, according to World Health Organization (WHO).
Preventing Land Pollution
Land pollution can occur naturally, but the majority of the issues that face the world today are manmade or intensified by people. Some of the causes can be resolved by those creating the pollution by taking preventative measures. Other causes like deforestation and climate change need long term solutions.