Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem. In the case of contaminants which occur naturally in soil, even when their levels are not high enough to pose a risk, soil pollution is still said to occur if the levels of the contaminants in soil exceed the levels that should naturally be present.

Soil Pollution Causes

All soils, whether polluted or unpolluted, contain a variety of compounds (contaminants) which are naturally present. Such contaminants include metals, inorganic ions and salts (e.g. phosphates, carbonates, sulfates, nitrates), and many organic compounds (such as lipids, proteins, DNA, fatty acids, hydrocarbons, PAHs, alcohols, etc.). These compounds are mainly formed through soil microbial activity and decomposition of organisms (e.g., plants and animals). Additionally, various compounds get into the soil from the atmosphere, for instance with precipitation water, as well as by wind activity or other types of soil disturbances, and from surface water bodies and shallow groundwater flowing through the soil. When the amounts of soil contaminants exceed natural levels (what is naturally present in various soils), pollution is generated. There are two main causes through which soil pollution is generated: anthropogenic (man-made) causes and natural causes.

Types of Soil Pollutants

Soil pollution consists of pollutants and contaminants. The main pollutants of the soil are the biological agents and some of the human activities. Soil contaminants are all products of soil pollutants that contaminate the soil. Human activities that pollute the soil range from agricultural practices that infest the crops with pesticide chemicals to urban or industrial wastes or radioactive emissions that contaminate the soil with various toxic substances.

BIOLOGICAL AGENTS

Biological agents work inside the soil to introduce manures and digested sludge (coming from the human, bird and animal excreta) into the soil.

AGRICULTURAL PRACTICES

The soil of the crops is polluted to a large extent with pesticides, fertilizers, herbicides, slurry, debris, and manure.

RADIOACTIVE POLLUTANTS

Radioactive substances such as Radium, Thorium, Uranium, Nitrogen, etc. can infiltrate the soil and create toxic effects.

URBAN WASTE

Urban waste consists of garbage and rubbish materials, dried sludge and sewage from domestic and commercial waste.

INDUSTRIAL WASTE

Steel, pesticides, textiles, drugs, glass, cement, petroleum, etc. are produced by paper mills, oil refineries, sugar factories, petroleum industries and others as such.

INDUSTRIAL WASTE

Examples of Soil Contaminants

There is a large variety of pollutants that could poison the soil. Examples of the most common and problematic soil pollutants can be found below.

The Effects of Soil Pollution

Soil pollution affects plants, animals and humans alike. While anyone is susceptible to soil pollution, soil pollution effects may vary based on age, general health status and other factors, such as the type of pollutant or contaminant inhaled or ingested. However, children are usually more susceptible to exposure to contaminants, because they come in close contact with the soil by playing in the ground; combined with lower thresholds for disease, this triggers higher risks than for adults. Therefore, it is always important to test the soil before allowing your kids to play there, especially if you live in a highly industrialized area.

Diseases Caused by Soil Pollution

Humans can be affected by soil pollution through the inhalation of gases emitted from soils moving upward, or through the inhalation of matter that is disturbed and transported by the wind because of the various human activities on the ground. Soil pollution may cause a variety of health problems, starting with headaches, nausea, fatigue, skin rash, eye irritation and potentially resulting in more serious conditions like neuromuscular blockage, kidney and liver damage and various forms of cancer.

Soil Pollution Facts

Soil acts as a natural sink for contaminants, by accumulating and sometimes concentrating contaminants which end up in soil from various sources. Tiny amounts of contaminants accumulate in the soil and - depending on the environmental conditions (including soil types) and the degradability of the released contaminant - can reach high levels and pollute the soil. If the soil is contaminated, home-grown vegetables and fruits may become polluted too. This happens because most of the soil pollutants present in the soil are extracted by the plants along with water every time they feed. Thus, it is always prudent to test the soil before starting to grow anything edible. This is especially important if your garden is located near an industrial or mining area, or within 1 mile of a main airport, harbor, landfill, or foundry.

Lead Poisoning

Lead is one of the most common elements in our world. It is becoming increasingly common in the universe as heavier atoms decay to lead, and there are massive lead resources on Earth – meaning we can assume there will be no lead shortage in the foreseeable future. Etymologically, the Germanic word lead and the Latin plumbum, which gave it the Pb notation in the table of elements, may have the same origin in the Proto-Indo-European lAudh orɸloud-io.

Chemical Properties

Contrary to popular belief, lead is not very heavy in itself. It is silvery with a blue tinge, and is a soft, malleable material.

Lead has been in use since the ancient times because it is widely available through easy and cheap extraction and processing. It is available (rarely) in native form, and more widely found in galena ores, as well as anglesite, cerrusite or boulangerite ores.

This metal easily changes color through corrosion or heating, which led alchemists to believe that it, in fact, turned into other metals or that it had near-magic properties.

Uses

As it has a low melting point and high density, lead was used in numerous household and engineering products throughout history. Its use has now declined in commercially available items, because of its toxicity.

Lead was widely known beginning with the period around 6,000 B.C, and was later used by the Romans to make water pipes, which gave an enormous advantage to the Roman empire (although it was offset by even bigger long-term disadvantages).

For thousands of years, lead was a common component in numerous everyday items, from drinking cups to enamels. In more recent times, it became a massive "ingredient" in industrial production.

water pipes
coffins
tableware
bullets
fuel additive
paint
cosmetics
batteries
canning

Toxicity

Lead is dangerous even at the smallest levels, especially when these levels are sustained in time. It is extremely toxic for young children even in low doses, and in higher doses it can be fatal for humans in general.

Lead poisoning symptoms include:

Weight loss
Irritability and mood disorders
Learning difficulties
Abdominal cramps and vomiting
Fatigue
Neurological problems
Headache
Autism in genetically predisposed people
Growth reduction
Impairs the pituitary-thyroid endocrine system
Favors osteoporosis

Mercury Poisoning

You must have heard about quicksilver. Did you know it’s the same thing as the chemical element mercury? It was known as quicksilver because in fact this is what it looks like to the naked eye: like a running silvery liquid.

Chemical Properties

Mercury is a fascinating metal. Not quite the only one to be liquid (bromine, gallium, caesium and rubidium are also liquid), it is however the only one that is liquid at normal temperature and pressure. Its chemical symbol in the table of elements is Hg, which comes from the Greek term hydrargyrum (literally quicksilver); its current name comes from the planet Mercury.

Mercury is not found as such in nature, but rather has to be mined out from cinnabar deposits. It easily forms bonds with other metals, such as silver or gold; what this means is that it could be used to form, for instance, silver and mercury amalgams that were widely used in dentistry as fillings. What this also means is that it was not easy to find a metal container for carrying mercury, as most metals will be dissolved in contact with it. Iron is an exception.

Mercury is a good conductor of electricity, and was for a long time thought to have medicinal qualities (which were later, for the most part, refuted by science or counter-weighed by its toxic effects.)

Uses

The use of mercury has been severely cut down in the past years, especially in more advanced countries. However, in many places it is still not fully regulated and therefore still present on the market in various products:

electrical switches or other electric and electronic parts
thermometers
fluorescent lamps
some types of telescopes
certain types of weapons
certain types of drugs (antiseptic ointments, eye drops, diuretics, laxatives)
cosmetics (mascara, skin care products)
dental amalgams
vaccines (in a fraudulent study later debunked, it was claimed the Thimerosal/Thiomersal mercury compound used as a preservative in vaccines was responsible for causing autism. Today, it has been repeatedly proven that there is no such link; moreover, the compound was removed from vaccines years ago)
medical products (it was used in the treatment of syphilis and in traditional Chinese medicine)
batteries

Toxicity

The reason for the removal of mercury from most products commercially available in the U.S. is that numerous studies have confirmed its great toxicity. Because mercury can be present in many forms – metal, vapor or salt – and in many compounds, we may not always be aware that contact has taken place. However, mercury can be inhaled or absorbed through the skin, and mercury poisoning is extremely dangerous. The phrase "mad as a hatter" comes from a historical fact: for a few centuries, up to the 19th century, hatters used a mercury nitrate compound in the treatment of the pelts and materials used for the making of hats. As a result, they displayed symptoms of "madness", i.e. of mercury poisoning:

Muscle weakness and atrophy
A tingling sensation in one’s limbs
Speech impairment
Loss of balance and coordination
Tremors
Depression, mood changes
Headaches
Severe neurological damage
Itching, burning, pain
Damage to brain, kidneys, and lungs
Pink disease (acrodynia) – skin discoloration (pink cheeks, fingertips, toes), while red cheeks and nose in affected children
Desquamation (peeling off in layers of dead skin)
High blood pressure and hypersalivation
Tachycardia
Loss of hair, teeth, nails, photophobia, kidney dysfunction, memory impairment, insomnia in children

Arsenic Poisoning

It’s a mainstay of detective fiction; it’s a naturally occurring element in the earth’s crust, from which it spreads through water, soil and air; it’s useful in many ways, but toxic in even more ways. Arsenic is a very versatile element, and it has been known to humans for millennia. The term itself comes from the Arabic word al zarniqa, meaning “yellow”.

Chemical Properties

Arsenic is a metalloid that can occur as a pure crystal, as well as in various minerals. Inorganic arsenic is extremely toxic, more so than organic arsenic compounds.

The most common arsenic allotropes (forms in which an element can exist) are gray, yellow, and black.

When exposed to humidity, arsenic turns golden-bronze and black.

Uses

For a number of centuries, arsenic was widely used in medicine, for instance as stimulants or to treat syphilis, leukemia and other cancers, psoriasis etc. In recent years, arsenic-74 is sometimes used in PET scans instead of iodine-124 to help detect the presence of tumors.

Other products in which arsenic was or is used include:

plumbing
glass
pigments
ammunition
textile
paper
pharmaceuticals
pesticides
par batteries
semiconductors

Toxicity

Arsenic is naturally present in the environment and can be released through volcanic explosions or contaminated groundwater in areas with high concentrations of arsenic.

Symptoms of arsenic poisoning include:

vomiting (including vomiting blood)
abdominal pain
diarrhea (including with blood)
tingling in fingers and toes
muscle cramps
blood in urine
hair loss
neurotoxicity
developmental effects
skin pigmentation, hard patches on hands and feet, and skin lesion in cases of long-term exposure (five or more years)
bladder or lung cancer in cases of long-term exposure
pulmonary disease
diabetes
various cardiovascular conditions (myocardial infarction is a relatively common condition whose risk of occurrence is enhanced by arsenic exposure)
pregnancy complications, infant mortality, cognitive problems in infants

If ingested – the most specific effects relates to skin pattern changes and cancer (including liver, kidney, bladder, prostate and lung cancer); also at lower doses, the digestive system may be affected with symptoms such as nausea vomiting, stomach irritation, diarrhea, damage to blood vessels.

If inhaled – skin changes; irritation of throat and lungs, circulatory problems, nervous system disorders

Copper Poisoning

Copper (noted in the table of elements as Cu, from the Latin cuprum, a corrupted form of the name Cyprium, from the island where it was mined by the Romans)) is a soft, highly conductive metal. It is a common metal easily mined and easily available – allowing for millions of years of human use at the current rate.

Chemical Properties

Copper can be found as such in nature, and it doesn’t need extraction, which made it available for extensive use by humans as early as 8,000 B.C. It is highly ductile and conductive, which makes it very useful for various industries.

Although orange red when exposed to air, it does oxidize slowly and turns black or, over time, green. The most famous example of such verdigris coloration of a copper layer is in the Statue of Liberty. In various combinations, it can acquire various other colors and tinges.

Copper is also extremely useful in various alloys, such as brass (copper and zinc) or bronze (copper and tin or aluminum). It is used in jewelry solders, undersea or seaside construction, ornaments, household items etc., precisely because it is resistant to corrosion.

Uses

Copper is naturally found in all living organisms, and in many it constitutes part of the blood pigment. In humans it is commonly found in the liver, bones and muscles.

Roofing
Electrical wires
Circuit boards
Plumbing
Industrial machinery
Pigments
Decorations
Preservatives
Fungicides
Distillery stills
Biostatic and antimicrobial linings

Toxicity

Although copper is essential to humans in very small doses, exposure to excess levels can be extremely harmful. Sources of copper toxicity can be anything from exposed copper in cookware to contaminated drinking water or excessive use of supplement pills. Copper wiring, insecticides and other unprotected products rich in copper can also represent contaminants. Symptoms of copper poisoning include:

Abdominal pain
Weakness
Nausea and vomiting
Headaches
Metallic taste in the mouth
Chills
Anemia
Yellow eyes and skin pigmentation
Liver or kidney failure in extreme cases

Zinc Poisoning

Zinc is the element most commonly found in the Earth’s crust. Sphalerite is the most common zinc ore. In various forms, zinc was used as early as 3,000 years B.C., from Greece to West India. However, it was only produced on a large scale in Europe in the 16th century, 4 centuries later than in India, and it was only discovered in pure metallic form by a German chemist in the mid 18th century. Fifty years later, Galvani and Volta made it famous through their electrochemical tests (the name galvanization derives from Luigi Galvani).

Chemical Properties

Zinc is a diamagnetic metal (i.e. repelled by magnetic materials) of a white-blue color, that becomes malleable at temperatures above 100 Celsius degrees. It is a good conductor of electricity, and is common in various alloys, including brass, and reacts with various non-metals.

Uses

Zinc was and is still used in plating because of its anti-corrosive properties. It is also used in batteries, and its alloys and compounds are also very common in contemporary life. Some of the products that use zinc are:

deodorants
batteries
Luminescent paints
non-corrosive iron plating
anti-dandruff shampoos
fire retardants
wood preservatives
fungicides
military uses (in propellants, weapons etc)

In the human body, zinc is an essential element. It helps in the metabolism of RNA and DNA, in the processing of proteins, in modulating neural responses and many other functions. There are serious consequences to decreased zinc levels (from diarrhea, impotence and skin lesions to cognition problems), just as there are serious consequences to excess zinc levels. There are natural zinc sources such as various types of protein foods and even some plants, as well as various beans and nut types. Other sources are dietary supplements and zinc-enriched foods, although they appear to be less effective.

Toxicity

Zinc can easily contaminate the soil and water in areas where it is naturally present or mined. When ingested in excess, whether voluntarily through supplements or involuntarily through exposure to contaminated soil or water, zinc can cause various health problems.

copper deficiency
urinary problems
anosmia (loss of smell)
genetic defects
fungal sepsis
lethargy
neurological problems
organ damage

Nickel Poisoning

Nickel is a ductile metal, silver in color (for which reason it was mistaken, for a long time, for silver) and relatively hard. It has been used for millennia, but it was first isolated in mid-18th century and named for a German legendary mining character. It was initially isolated from cupronickel, but later other sources became known. It is often extracted from pyrrhotite or during the production of cobalt blue.

Chemical Properties

Nickel is useful because of its resistance to corrosion, and it is a good conductor of electricity and heat. It is malleable and reacts very slowly to exposure. It is ferromagnetic, meaning it reacts strongly to magnetization.

Uses

For a long time, humans were unable to extract nickel and merely used it incidentally or sporadically in plating and various alloys that were attractive because of their polished finish. Since the mid-19th century it has been commonly used in coins, and later acquired various other uses, in many cases in various alloys:

Coins
Stainless steel
Wiring
Electric guitar strings
Jewelry
Plumbing
Propeller shafts
Tints
Faucets
Cookware
Detergents
Rechargeable batteries
Industrial uses (industrial magnets, gas turbines, etc.)
Dental fillings, orthodontics etc.
Surgical implants
Foods (imitation whipped cream or butter

Toxicity

While nickel can be naturally found in water and soil, it is often encountered in areas with human pollution. In small quantities, it is eliminated through urine or the intestinal tract; in larger doses, however, it is toxic and may cause serious health conditions:

Contact dermatitis
Lung cancer
Neurological problems
Childhood developmental issues
Kidney and liver failure
Cardiovascular disease

PAHs - Polyaromatic Hydrocarbons Pollution

Polyaromatic hydrocarbons are thought to be extremely old compounds, with essential roles in the formation of stars, planets and possibly life itself. However, they are also extremely toxic to humans, and are present in countless shapes and forms all around us, from wood smoke and cigarette smoke to vehicle exhaust.

Chemical Properties

Polyaromatic hydrocarbons (also known as polycyclic aromatic hydrocarbons or polynuclear aromatic hydrocarbons) are organic compounds made up of carbon and hydrogen. Under various combinations, they can form more than 100 chemicals, all of which are toxic in certain amounts and to certain degrees. (The term "aromatic" as used in chemistry has nothing to do with its common layman use, and refers to certain stable organic ring-shaped molecules.) PAHs can occur naturally or be man-made.

Uses

While PAHs usually occur unintentionally, and therefore usually have no "uses" as such, they are employed to a certain extent in various industries:

Agrochemical products
Photography
Medicines
Plastics
Dyes
Pesticides
Pigments

Toxicity

PAHs are among the most common pollutants throughout human history, because they occur naturally as a result of many basic human activities. The most widely encountered PAH-producing activity in older times was cooking on a wood-burning stove or grill, and heating houses through wood burning activities.

In more recent times, there are other powerful PAH pollutants as well:

smoking and vehicle emissions
the manufacturing of various metals
shale oil extraction
the processing of coke, calcium carbide, creosote etc.
the production of rubber tires
asphalt manufacturing
natural gas power stations

Depending on the regulations enforced in each country, some of these PAH pollution factors are better controlled. In poorer countries, with lower levels of enforcement, PAH pollution is more severe. This is worrying, as some PAHs are known carcinogens. Exposure to high levels, for instance when breathing coal tar vapors or otherwise being exposed to large quantities of various PAHs, can cause:

convulsions
respiratory tract diseases
mutagenic effects
immunosuppression
cancer
liver damage

Herbicides & Insecticides Poisoning

Herbicides and insecticides are chemical or biological agents used to kill unwanted pests that may diminish crops or otherwise affect human life. They are known for their beneficial effects, as well as for the hazards they may pose to the environment.

Chemical Properties

Insecticides include organochlorines, organophosphates, and carbamates. Herbicides can be phenoxy and benzoic acid herbicides, triazines, ureasetc. Other pesticides can include glyphosate and other compounds. They use different methods of affecting their target, from poisoning the organism through interfering with photosynthesis.

Uses

While herbicides and insecticides are helpful in getting rid of pests of various kinds, the wider public may be unaware that they mostly reach unwanted targets. As most of them are not strictly targeted to their object, they can be carried into the water, soil or air around them and have numerous adverse effects on humans and the environment.

Studies show that every single water stream examined in the U.S. showed traces of pesticide pollution. Herbicides and insecticides were also identified in significant quantities in rain and groundwater. They are also damaging to bee populations and food sources, so that certain animals can be deprived of their food sources and caused to starve or relocate (birds and fish among them).

Toxicity

For humans, herbicides and insecticides are known pollutants. They can be inhaled, ingested through food or water or become harmful through direct skin contact. Depending on the length of exposure and the concentration of the pollutants, they cause serious health concerns, for children particularly, but also for adults.

Birth defects
Endocrine disruption
Reproductive problems
Leukemia and other cancers
Blood disorders
Diseases of the nervous system
Diseases of the immune system

Soil Pollution Causes

There are numerous causes of soil pollution that occur every day or even every minute. For ease of reference, they are generally split into two: man-made (anthropogenic) causes and naturally occurring causes.

Man-Made Pollutants

Anthropogenic (man-made) soil pollution originates in several types of processes, some deliberate (industrial) and some accidental. Human-caused soil pollution can work in conjunction with natural processes to increase the toxic contamination levels in the soil.

Accidental spills and leaks during storage, transport or use of chemicals (e.g. leaks and spills of gasoline and diesel at gas stations);
Foundry activities and manufacturing processes that involve furnaces or other processes resulting in the possible dispersion of contaminants in the environment;
Mining activities involving the crushing and processing of raw materials, for instance, heavy metals, emitting toxic substances;
Construction activities (see below)
Agricultural activities involving the diffusion of herbicides, pesticides and/or insecticides and fertilizers;
Transportation activities, releasing toxic vehicle emissions
Chemical waste dumping, whether accidental or deliberate – such as illegal dumping;
The storage of waste in landfills, as the waste products may leak into groundwater or generate polluted vapors
Cracked paint chips falling from building walls, especially lead-based paint.

Construction sites are the most important triggers of soil pollution in urban areas, due to their almost ubiquitous nature. Almost any chemical substance handled at construction sites may pollute the soil. However, the higher risk comes from those chemicals that can travel more easily through the air as fine particulate matter. The chemicals that travel as particulate matter are more resistant to degradation and bioaccumulate in living organisms, such as PAHs.

Additionally, construction dust may easily spread around through the air and is especially dangerous because of its lower particle size (less than 10 microns). Such construction dust can trigger respiratory illnesses such as asthma and bronchitis, and even cancer. Moreover, the sites that involve the demolition of older buildings can release asbestos, a toxic mineral that can act as a poison in soil. Asbestos particles can be redistributed by the wind.

Natural Pollutants

Apart from the rare cases when a natural accumulation of chemicals leads to soil pollution, natural processes may also have an influence on the human released toxic chemicals into the soil, overall decreasing or increasing the pollutant toxicity and/or the level of contamination of the soil. This is possible due to the complex soil environment, involving the presence of other chemicals and natural conditions which may interact with the released pollutants.

Natural processes leading to soil pollution:

Natural accumulation of compounds in soil due to imbalances between atmospheric deposition and leaking away with precipitation water (e.g., concentration and accumulation of perchlorate in soils in arid environments)
Natural production in soil under certain environmental conditions (e.g., natural formation of perchlorate in soil in the presence of a chlorine source, metallic object and using the energy generated by a thunderstorm)
Leaks from sewer lines into subsurface (e.g., adding chlorine which could generate trihalomethanes such as chloroform).

What is Soil Pollution?

Soil pollution is the build-up of chemicals, radioactive materials, toxic compounds, and disease-causing agents in the soil to levels that can cause adverse effects on plant growth and damage to both human and animal health. The pollution of the soil is either caused by natural activities or human actions which destroy its properties such as structure, composition and soil biota.

Naturally, the soil contains contaminants such as metals, salts, inorganic ions, and organic compounds that are mainly formed through soil microbial activity. These natural compounds (contaminants) rarely build up to generate pollution. In most cases, however, the soil is polluted because of human activities and usually result in both long-term and short-term impacts. Essentially, it leads to the deterioration of the soil’s mineral content, quality, and texture.

By-products and waste generated from households, industries, artificial chemicals, petroleum products, and mining sites are the leading contributors to soil pollution. Some of the soil pollutants are biodegradable and decompose gradually after a given some time. Others are non-biodegradable, which means they can persist in the soil for a long period. The soil pollutants can be classified as physical, biological, and chemical. Here is a discussion on the sources and solutions to soil pollution.

Various Sources of Soil Pollution

1. Agricultural sources

Agricultural practices such as the use of non-organic products in crop and livestock production lead to soil pollution. These substances include artificial chemical pesticides, herbicides, fungicides, and fertilizers as discussed below:

Pesticides, herbicides, and insecticides. The introduction of modern pesticides, herbicides, and insecticides has resulted in an increase in the use of agricultural chemicals. These chemicals are used to control the pests, insects, weeds, fungi, and diseases that attack crops. Most of these chemicals are non-biodegradable while others decompose to products that are toxic to soil. These products seep into the ground and act on the soil thereby changing its structure, composition, and pH.

Improper use of fertilizer. Fertilizers are mostly used to correct the deficiency of soil nutrients. A soil which is deficient of potassium, calcium, nitrogen, and sulfur among other important macro-nutrients should be treated with the right fertilizer and at the right amount. However, some farmers use them indiscriminately leading to soil pollution. What is more, the materials used to manufacture fertilizers contain impurities that add to soil toxicity. For instance, the rock phosphates mineral used for the manufacture of mixed fertilizers contain traces of Asbestos, Cadmium, and Lead which are transferred to the fertilizer during production. These metals are non-biodegradable and with time accumulate to toxic levels.

2. Industrial sources

Industrial wastes or byproducts are among the leading causes of soil pollution. They can be in the form of gas, liquid or solid substances. Carbon dioxide, nitrogen dioxide, sulfur dioxide, and carbon monoxide are some of the gases produced from industrial activities that cause considerable pollution to soil indirectly.

They combine with the rainwater causing the production of acidic rain which changes the soil pH and thereafter affects the overall crop production. Industries also dump their solid and liquid effluents into the soil.

3. Urban waste

Most developing countries have a problem of controlling the disposal of municipal garbage. The garbage is dumped anyhow and contains wastes such as food waste, plastics, industrial wastes, e-waste, and general household wastes. It appears as if the urban administrators do not know that most of the non-biodegradable waste materials could be recycled and the organic materials disposed of in areas designated for natural decomposition.

4. Sewer sludge

Sewage plants also contribute to soil pollution owing to how they dispose of sewage sludge from domestic and commercial waste. The sewage sludge is usually treated before being disposed into land or water bodies. When disposed on land, the sludge can release high amounts of nutrients depending on the source that may surpass the natural soil nutrient requirement thus posing a risk to human health and/or the ecosystem at large. Sewer sludge may also contain high levels of metals, further polluting the soil.

5. Mining and Smelting sources

Mining activities cause soil pollution on a large scale. The operations cause a change of the landscape and expose the previously undisturbed soils to the elements of weather. Erosion of the soil containing some traces of mineral ores and fine materials around the mining areas result in sediment loading in the water sources and drainage ways. They end up into the soil through irrigation and flowing stormwater.

There are also other hazardous materials that leak from mining activities including harmful dust particles which are deposited on the surrounding soils. In developing countries, the pollution levels are even higher because activities such as gold mining are done using traditional methods which lead to the release of mercury and other heavy metals into rivers and neighboring lands. Some of the polluted rivers are also used for irrigation further leading to the pollution of the irrigated soils.

6. Nuclear sources

Every living organism is continuously exposed to background radiations. If the levels of these radiations exceed a given limit, they lead to disastrous effects. Radiation pollution results from two sources, that is, the natural and anthropogenic actions. In nature, there are radioactive minerals that contribute to soil pollution such as the radon-222 and Radium,-226 which are found in rocks. Improper disposal of wastes from nuclear plants can, therefore, result in soil pollution and contamination.

7. Deforestation

Though not a direct contributing factor to soil pollution, deforestation leads to the removal of the shield that protects the soil against the agents of erosion. The exposed soil is easily eroded and exposed to artificial chemical pollutants from the air, wind, and rain.

Incredible Solutions to Soil Pollution

To reduce soil pollution, there is a need to adopt the Reduce, Reuse and Recyclestrategy. Some of the solutions to soil pollution include;

1. Reduction of artificial fertilizers and pesticides use

Use of organic means of farming can reduce soil pollution on a global scale. Bio-fertilizers and manures reduce the need for chemical fertilizer. Pests and diseases in crops can also be controlled through the use of biological methods, consequently reducing soil pollution.

2. Reusing and Recycling of materials

Glass containers, papers, and cloth materials, as well as products, can be reused at domestic levels in a bid to reduce soil pollution. Reusing will limit the need for replacing the used products thus relatively reducing the number of household waste products such as plastics and e-waste that are sent to the landfill. Recycling is another means of reducing the disposed of wastes. Some plastics and glass can be recycled to lessen the volume of wastes and encourage environmental conservation.

3. Reforestation

Planting of more tree cover is the best way of reducing soil pollution through minimizing erosion and effects of floods. Reforestation achieves this by providing protective ground cover for the soil.

4. Physical methods (thermal)

Contaminants can be removed by evaporation. By application of the right temperature through indirect or direct heating, the pollutants can escape through the process of evaporation. Stream stripping is an example of such a method where a jet of steam is injected into the contaminated soil to cause evaporation of volatile pollutants.

However, this method is not sustainable because the release of the contaminants from the soil sends them into the atmosphere causing air pollution. As much as it’s an alternative method of addressing the impacts of soil pollution, emphasis should be on recycle, reuse, and reduce.

5. Chemical methods

In this method, the soil is brought into contact with the right chemical through a chemical process of restoring the natural chemical balance in the soil. It is done regularly to ensure that the detoxification process is complete.

6. The technique of extraction and separation

In this method, the technique of solvent extraction is used. An extracting agent is mixed with the contaminated soil. The extraction agent is mainly an organic solvent. This method can be applied in the removal of heavy metals in the soil such as arsenic, copper, lead, cadmium among others.

It can also be used in the removal of hydrocarbons and halogenated hydrocarbons. The impurities in the soil are mainly located in a finer and coarser part of the soil such as the hummus. Removal can be based on the separation of the particles of soil in fractions using the principle of the gravitational pull of different particles.

7. Microbial treatment

This method can deal with various types of organic contaminants including phenol, oil and its products, and polychlorinated hydrocarbons. The microbes are collected, cultured, and used to treat the environment. Before treatment, the soil is excavated and treated before standard agricultural techniques are applied.

8. Solid waste treatment

Solid wastes should be treated and discarded properly. They should be treated before dumping them through physical, chemical and biological means until their hazardous levels to the environment are reduced to the minimum requirement.

What is Land Pollution?

When we talk about air or water pollution, the reactions garnered are stronger. This is because we can see the effects caused by the pollutants and their extent very clearly. It is normal human psychology to believe in what you see first hand. Our land, on the other hand, is living a nightmare too. We may not be able to see the effects with clarity, but land is being polluted and abused constantly and we are unable to calculate the damages incurred. Land Pollution has come to become one of the serious concerns that we collectively battle.

Land pollution, in other words, means degradation or destruction of the Earth’s surface and soil, directly or indirectly as a result of human activities. Anthropogenic activities are conducted citing development, and the same affects the land drastically, we witness land pollution; by drastic we are referring to any activity that lessens the quality and/or productivity of the land as an ideal place for agriculture, forestation, construction, etc. The degradation of land that could be used constructively, in other words, is land pollution.

Land Pollution has led to a series of issues that we have come to realize in recent times, after decades of neglect. The increasing numbers of barren land plots and the decreasing numbers of forest cover are increasing at an alarming ratio. Moreover, the extension of cities and towns due to the increasing population is leading to further exploitation of the land.

Landfills and reclamations are being planned and executed to meet the increased demand for lands. This leads to further deterioration of land, and pollution caused by the landfill contents. Also due to the lack of green cover, the land gets affected in several ways like soil erosion occurs washing away the fertile portions of the land. Or even a landslide can be seen as an example.

Causes of Land Pollution

1. Deforestation and soil erosion

Deforestation carried out to create dry lands is one of the major concerns. Land that is once converted into dry or barren land, can never be made fertile again, whatever the magnitude of measures to redeem it is. Land conversion, meaning the alteration or modification of the original properties of the land to make it use-worthy for a specific purpose is another major cause. This hampers the land immensely.

Also there is a constant waste of land. Unused available land over the years turns barren; this land then cannot be used. So in search of more land, potent land is hunted and its indigenous state is compromised with.

2. Agricultural activities

With the growing human population, demand for food has increased considerably. Farmers often use highly toxic fertilizers and pesticides to get rid off insects, fungi and bacteria from their crops. However with the overuse of these chemicals, they result in contamination and poisoning of soil.

3. Mining activities

During extraction and mining activities, several land spaces are created beneath the surface. We constant hear about land caving in; this is nothing but nature’s way of filling the spaces left out after mining or extraction activity.

4. Overcrowded landfills

Each household produces tonnes of garbage each year. Garbage like aluminum, plastic, paper, cloth, wood is collected and sent to the local recycling unit. Items that can not be recycled become a part of the landfills that hampers the beauty of the city and cause land pollution.

5. Industrialization

Due to an increase in demand for food, shelter, and house, more goods are produced. This resulted in creation of more waste that needs to be disposed of. To meet the demand of the growing population, more industries were developed which led to deforestation. Research and development paved the way for modern fertilizers and chemicals that were highly toxic and led to soil contamination.

6. Construction activities

Due to urbanization, a large number of construction activities are taking place which has resulted in large waste articles like wood, metal, bricks, plastic that can be seen by naked eyes outside any building or office which is under construction.

7. Nuclear waste

Nuclear plants can produce a huge amount of energy through nuclear fission and fusion. The left over radioactive material contains harmful and toxic chemicals that can affect human health. They are dumped beneath the earth to avoid any casualty.

8. Sewage treatment

A large amount of solid waste is leftover once the sewage has been treated. The leftover material is sent to landfill site which end up in polluting the environment.

Effects of Land Pollution

1. Soil pollution

Soil pollution is another form of land pollution, where the upper layer of the soil is damaged. This is caused by the overuse of chemical fertilizers, soil erosion caused by running water and other pest control measures; this leads to loss of fertile land for agriculture, forest cover, fodder patches for grazing, etc.

2. Change in climate patterns

The effects of land pollution are very hazardous and can lead to the loss of ecosystems. When land is polluted, it directly or indirectly affects the climate patterns.

3. Environmental impact

When deforestation is committed, the tree cover is compromised. This leads to a steep imbalance in the rain cycle. A disturbed rain cycle affects a lot of factors. To begin with, the green cover is reduced. Trees and plants help balance the atmosphere, without them we are subjected to various concerns like Global warming, the greenhouse effect, irregular rainfall and flash floods among other imbalances.

4. Effect on human health

The land when contaminated with toxic chemicals and pesticides lead to the problem of skin cancer and the human respiratory system. The toxic chemicals can reach our body through foods and vegetables that we eat as they are grown in polluted soil.

Causes air pollution

Landfills across the city keep on growing due to an increase in waste and are later burned which leads to air pollution. They become home for rodents, mice, etc which in turn transmit diseases.

6. Distraction for tourists

The city loses its attraction as a tourist destination as landfills do not look good when you move around the city. It leads to a loss of revenue for the state government.

7. Effect on wildlife

The animal kingdom has suffered most in the past decades. They face a serious threat with regards to the loss of habitat and natural environment. The constant human activity on land, is leaving it polluted; forcing these species to move further away and adapt to new regions or die trying to adjust. Several species are pushed to the verge of extinction, due to no homeland.

Other issues that we face include increased temperature, unseasonal weather activity, acid rains, etc. The discharge of chemicals on land, makes it dangerous for the ecosystem too. These chemicals are consumed by the animals and plants and thereby make their way in the ecosystem. This process is called biomagnification and is a serious threat to the ecology.

Solutions for Land Pollution

1. Make people aware of the concept of Reduce, Recycle and Reuse.

2. Reduce the use of pesticides and fertilizers in agricultural activities.

3. Avoid buying packages items as they will lead to garbage and end up in the landfill site.

4. Ensure that you do not litter on the ground and do proper disposal of garbage.

5. Buy biodegradable products.

6. Do organic gardening and eat organic food that will be grown without the use of pesticides.

7. Create dumping ground away from residential areas.

Several creatures survive under the land too. Disrupting the harmony of the land is disrupting their habitat. This has led to several creatures reaching the endangered status like Gilbert’s Potoroo in Australia.

We walk and survive on land. It is literally the base of our ecosystem. It is in our good interest to take care of it and nurture it.

What is Soil Pollution?

With the rise of concrete buildings and roads, one part of the Earth that we rarely see is the soil. It has many different names, such as dirt, mud, and ground. However, it is definitely very important to us. The plants that feed us grow in soil and keeping it healthy is essential to maintaining a beautiful planet. However, like all other forms of nature, soil also suffers from pollution. The pollution of soil is a common thing these days, and it happens due to the presence of man-made elements.

The main reason why the soil becomes contaminated is due to the presence of man-made waste. The waste produced from nature itself such as dead plants, carcasses of animals and rotten fruits and vegetables only adds to the fertility of the soil. However, our waste products are full of chemicals that are not originally found in nature and lead to soil pollution.

Main Causes of Soil Pollution

1. Industrial Activity

Industrial activity has been the biggest contributor to the problem in the last century, especially since the amount of mining and manufacturing has increased. Most industries are dependent on extracting minerals from the Earth. Whether it is iron ore or coal, the by-products are contaminated and they are not disposed of in a manner that can be considered safe. As a result, the industrial waste lingers in the soil surface for a long time and makes it unsuitable for use.

2. Agricultural Activities

Chemical utilization has gone up tremendously since technology provided us with modern pesticides and fertilizers. They are full of chemicals that are not produced in nature and cannot be broken down by it. As a result, they seep into the ground after they mix with water and slowly reduce the fertility of the soil.

Other chemicals damage the composition of the soil and make it easier to erode by water and air. Plants absorb many of these pesticides and when they decompose, they cause soil pollution since they become a part of the land.

3. Waste Disposal

Finally, a growing cause for concern is how we dispose of our waste. While industrial waste is sure to cause contamination, there is another way in which we are adding to the pollution. Every human produces a certain amount of personal waste products by way or urine and feces.

While much of it moves into the sewer the system, there is also a large amount that is dumped directly into landfills in the form of diapers. Even the sewer system ends at the landfill, where the biological waste pollutes the soil and water. This is because our bodies are full of toxins and chemicals which are now seeping into the land and causing pollution of soil.

4. Accidental Oil Spills

Oil leaks can happen during storage and transport of chemicals. This can be seen at most of the fuel stations. The chemicals present in the fuel deteriorates the quality of soil and make them unsuitable for cultivation. These chemicals can enter into the groundwater through the soil and make the water undrinkable.

5. Acid Rain

Acid rain is caused when pollutants present in the air mix up with the rain and fall back on the ground. The polluted water could dissolve away some of the important nutrients found in soil and change the structure of the soil.

Effects of Soil Pollution

1. Effect on Health of Humans

Considering how soil is the reason we are able to sustain ourselves, the contamination of it has major consequences on our health. Crops and plants are grown on polluted soil absorb much of the pollution and then pass these on to us. This could explain the sudden surge in small and terminal illnesses.

Long term exposure to such soil can affect the genetic make-up of the body, causing congenital illnesses and chronic health problems that cannot be cured easily. In fact, it can sicken the livestock to a considerable extent and cause food poisoning over a long period of time. The soil pollution can even lead to widespread famines if the plants are unable to grow in it.

2. Effect on Growth of Plants

The ecological balance of any system gets affected due to the widespread contamination of the soil. Most plants are unable to adapt when the chemistry of the soil changes so radically in a short period of time. Fungi and bacteria found in the soil that bind it together begin to decline, which creates an additional problem of soil erosion.

The fertility slowly diminishes, making land unsuitable for agriculture and any local vegetation to survive. The soil pollution causes large tracts of land to become hazardous to health. Unlike deserts, which are suitable for its native vegetation, such land cannot support most forms of life.

3. Decreased Soil Fertility

The toxic chemicals present in the soil can decrease soil fertility and therefore decrease in the soil yield. The contaminated soil is then used to produce fruits and vegetables which lacks quality nutrients and may contain some poisonous substance to cause serious health problems in people consuming them.

4. Toxic Dust

The emission of toxic and foul gases from landfills pollutes the environment and causes serious effects on the health of some people. The unpleasant smell causes inconvenience to other people.

5. Changes in Soil Structure

The death of many soil organisms (e.g. earthworms) in the soil can lead to alteration in soil structure. Apart from that, it could also force other predators to move to other places in search of food.

A number of ways have been suggested to curb the current rate of pollution. Such attempts at cleaning up the environment require plenty of time and resources to be pitched in. Industries have been given regulations for the disposal of hazardous waste, which aims at minimizing the area that becomes polluted.

Organic methods of farming are being supported, which do not use chemical-laden pesticides and fertilizers. Use of plants that can remove the pollutants from the soil is being encouraged. However, the road ahead is quite long and the prevention of soil pollution will take many more years.