Environmental Pollution, Its Sources and Effects

We discuss major aspects of this study area, from definitions to pollution types & sources as well as wide-ranging pollution effects.

So what is pollution? In order to get a better understanding of it, let’s have a look at some common definitions.

Perhaps the overriding theme of these definitions is the ability of the environment to absorb and adapt to changes brought about by human activities.

In one word, environmental pollution takes place when the environment cannot process and neutralize harmful by-products of human activities (for example, poisonous gas emissions) in due course without any structural or functional damage to its system.

In fact, “the due course” itself may last many years during which the nature will attempt to decompose the pollutants; in one of the worst cases – that of radioactive pollutants – it may take as long as thousands of years for the decomposition of such pollutants to be completed.

Pollution occurs, on the one hand, because the natural environment does not know how to decompose the unnaturally generated elements (i.e., anthropogenic pollutants), and, on the other, there is a lack of knowledge on the part of humans on how to decompose these pollutants artificially.

Why does pollution matter?

It matters first and foremost because it has negative impacts on crucial environmental services such as provision of clean air and clean water (and many others) without which life on Earth as we know it would not exist.

Introduction to Environmental Pollution

Although pollution had been known to exist for a very long time (at least since people started using fire thousands of years ago), it had seen the growth of truly global proportions only since the onset of the industrial revolution during the 19th century.

The industrial revolution brought with it technological progress such as discovery of oil and its virtually universal use throughout different industries.

Technological progress facilitated by super efficiency of capitalist business practices (division of labour – cheaper production costs – overproduction – overconsumption – overpollution) had probably become one of the main causes of serious deterioration of natural resources.

At the same time, of course, development of natural sciences led to the better understanding of negative effects produced by pollution on the environment.

Environmental pollution is a problem both in developed and developing countries. Factors such as population growth and urbanization invariably place greater demands on the planet and stretch the use of natural resources to the maximum.

It has been argued that the carrying capacity of Earth is significantly smaller than the demands placed on it by large numbers of human populations. And overuse of natural resources often results in nature’s degradation.

Environmental Pollutants:
What Are They & How Do They Decompose?

Environmental pollutants are constituent parts of the pollution process. They are the actual “executing agents” of environmental pollution.

They come in gaseous, solid or liquid form.

It is interesting to note that, as of 1990, there were around 65,000 different chemicals in the marketplace, i.e. potential environmental pollutants that were to be released into air, water and land on a regular basis. (Ref. 8)

We assume that, as of 2011 - 2012, this number may be significantly higher.

Renowned author Miguel A. Santos identifies at least three general characteristics of environmental pollutants (Ref. 9):

Beach pollution in Malaysia
which travels from China
© epSos.de
• Pollutants don't recognize boundaries, i.e. they are transboundary;
• Many of them can't be degraded by living organisms and therefore stay in the ecosphere for many years; and
• They destroy biota and habitat.

These points emphasize that pollutants present a serious long-term global problem that affects more or less every country and, therefore, can only be solved by a coordinated set of actions and unwavering commitment of nations to international environmental agreements.

In order to develop and implement an effective international policy for pollutants’ management, it is important, among other factors, to understand their decomposition mechanisms.

We know that decomposition of pollutants can occur either biologically or physicochemically. (Ref. 10)

Biological Decomposition of Environmental Pollutants

Santos divides environmental pollutants into biodegradable and non-biodegradable ones, and describes them as follows. (Ref. 11)

Biodegradable Pollutants

Fruit peel
is biodegradable
© Fotoos Van Robin

Biodegradable pollutants are the ones that can be broken down and processed by living organisms, including organic waste products, phosphates, and inorganic salts.

For example, if a pollutant is organic, it can be used by a living organism to obtain energy and other material from carbohydrates, proteins etc.

Therefore, biodegradable pollutants are only “temporary nuisances” that can be neutralised and converted into harmless compounds.

However, it is important to remember that they can become serious pollutants if released in large amounts in small areas, thus exceeding the natural capacity of the environment to “assimilate” them.

Non-Biodegradable Pollutants

Plastic may look
beautiful but it is
not biodegradable
© Nolte Lourens

Non-biodegradable pollutants are the ones that cannot be decomposed by living organisms and therefore persist in the ecosphere for extremely long periods of time.

They include plastics, metal, glass, some pesticides and herbicides, and radioactive isotopes.

In addition to that, fat soluble (but not water soluble) non-biodegradable pollutants, ex. mercury and some hydrocarbons, are not excreted with urine but are accumulated in the fat of living organisms and cannot be metabolised.

Non-Biological Decomposition of Environmental Pollutants (Ref. 12)

Non-biological decomposition of non-biodegradable pollutants requires a combination of many factors, such as wind, water and climate to work together to achieve neutralisation of pollutants.

Some of the most dangerous pollutants such as radioactive isotopes can decompose by themselves but it will take them thousands of years.

Removal of Air Pollutants from the Atmosphere (Ref. 13)

Air pollutants, as opposed to solid and liquid pollutants found on land and in water, may be removed from the atmosphere through wet deposition or dry deposition.

In case of wet deposition pollutants make way into clouds or other precipitation and then get deposited onto the surface of the Earth by way of rain. In case of dry deposition, pollutants are deposited directly onto the planet's surface and vegetation, such as plants and trees of tropical rainforests.

We may assume that once air pollution has been deposited onto the planet's surface, the normal rules of biological and non-biological decomposition for other types of pollutants will apply.

Types of Environmental Pollution

Generally speaking, there are many types of pollution but the most important ones are:

• Air pollution
• Water pollution
• Soil pollution (contamination)

Some of the most notable air pollutants are sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, volatile organic compounds (VOCs) and airborne particles, with radioactive pollutants probably among the most destructive ones (specifically when produced by nuclear explosions).

Our Air Pollutants article provides a clear overview of sources and effects of these air pollutants.

Water pollutants include insecticides and herbicides, food processing waste, pollutants from livestock operations, volatile organic compounds (VOCs), heavy metals, chemical waste and others.

Some soil pollutants are: hydrocarbons, solvents and heavy metals.

So where does environmental pollution come from?

Sources of Environmental Pollution

Fossil Fuel Sources of Environmental Pollution

In modern industrialized societies, fossil fuels (oil, gas, coal) transcended virtually all imaginable barriers and firmly established themselves in our everyday lives.

Not only do we use fossil fuels for our obvious everyday needs (such as filling a car), as well as in the power-generating industry, they (specifically oil) are also present in such products as all sorts of plastics, solvents, detergents, asphalt, lubricating oils, a wide range of chemicals for industrial use, etc. (Ref. 14)

Combustion of fossil fuels produces extremely high levels of air pollution and is widely recognized as one of the most important “target” areas for reduction and control of environmental pollution.

Fossil fuels also contribute to soil contamination and water pollution. For example, when oil is transported from the point of its production to further destinations by pipelines, an oil leak from the pipeline may occur and pollute soil and subsequently groundwater. When oil is transported by tankers by ocean, an oil spill may occur and pollute ocean water.

Of course, there are other natural resources whose exploitation is a cause of serious pollution; for example, the use of uranium for nuclear power generation produces extremely dangerous waste that would take thousands of years to neutralize.

But there is no reasonable doubt that fossil fuels are among the most serious sources of environmental pollution.

Power-generating plants and transport are probably the biggest sources of fossil fuel pollution.

Common sources of fossil fuel pollution are: (Ref. 15)

Industry:

• Power-generating plants
• Petroleum refineries
• Petrochemical plants
• Production and distribution of fossil fuels
• Other manufacturing facilities

Transport:

• Road transport (motor vehicles)
• Shipping industry
• Aircraft

Fossil fuel combustion is also a major source of carbon dioxide (CO2) emissions and perhaps the most important cause of global warming. Learn more about the causes and effects of global warming here.

Other (Non-Fossil Fuel) Sources of Environmental Pollution

Among other pollution sources, agriculture (livestock farming) is worth mentioning as the largest generator of ammonia emissions resulting in air pollution.

Chemicals such as pesticides and fertilizers are also widely used in agriculture, which may lead water pollution and soil contamination as well.

Trading activities may be another source of environmental pollution.

For example, it’s been recently noted that packaging of products sold in supermarkets and other retail outlets is far too excessive and generates large quantities of solid waste that ends up either in landfills or municipal incinerators leading to soil contamination and air pollution.

Residential sector is another significant source of pollution generating solid municipal waste that may end up in landfills or incinerators leading to soil contamination and air pollution.

Environmental Pollution Effects:
Bhopal Case Study

There is absolutely no doubt that pollution has grown into a serious environmental issue as we know it because of its undeniably adverse impact on our whole planet.

Environmental pollution affects not only people, animals and vegetation but also the wider environment such as mountains, rocks, lakes, rivers and so on.

Perhaps one of the best ways to demonstrate the damaging effects brought about by all types of pollution is to examine a well-known case study and see how all those involved are affected from a practical perspective.

In this respect, we believe that the Bhopal pollution disaster that took place in India in 1984 presents a suitable example for our purposes.

Bhopal Pollution Disaster:     What Exactly Happened in Bhopal in 1984?

On the night of December 2 1984, a deadly dosage of the poisonous methyl isocyanate gas leaked from a tank of the pesticides plant in Bhopal owned by the US company Union Carbide.

Here is what happened next:

The gases swirled across the ground into nearby bustees (slums), killing Bhopal's poorest inhabitants in their sleep, burning the eyes and lungs of survivors, and causing nearly two decades of deaths, injuries and ill health.

Estimates of the number of people killed on the first night range from an official figure of 3,000 to as many as 7,000 or 8,000 (partly based on the number of kafans, or shrouds, ordered by religious organisations for wrapping the dead). Since then, at least another 10,000 to 15,000 of those affected have died. (Ref. 16)

Since then the city of Bhopal has been called by some a "global toxic spot" and even a "Hiroshima of chemical disasters".

It is not the aim of this article to go into the causes of this horrendous accident.

But we feel that John Elliott of the UK's New Statesman quite correctly named it to be "a deadly blend of big corporation hubris and managerial incompetence" that led to this tragedy. (Ref. 17)

Another salient point to remember is that many people put into question the official version that it was methyl isocyanate (MIC) that was leaked from the storage tank.

The reason for such doubts is this:

Doctors who performed autopsies in the first twenty-four hours found high levels of cyanide in blood and tissues in the most severe cases. The chemical reaction that took place in the tank could have produced hydrogen cyanide.

Union Carbide and the government did not pursue this explanation because cyanide had been used in German concentration camps in the Second World War, and discovery that this was the cause of the deaths would have led to a very strong adverse public reaction. (Ref. 18)

Knowing the exact nature of the gas would have made the doctors' work much more effective in the years that followed - since this would have, of course, allowed them to better determine short- and long-term medical strategies for treating the victims.
(Ref. 19)

We will now try to summarize most environmental effects of this disaster that have been documented by various publications.

Air Pollution Effects of Bhopal Gas Leakage

So what do we know about MIC (assuming that was the gas that leaked)?

We know that MIC is an extremely toxic and reactive gas which should be handled with absolute caution.

Here is what Ashok Bhargava reports (Ref. 20):

The effects of [this] chemical on human beings resemble those of nerve gas.

Blind Woman, Bhopal
© Bbc.co.uk

The eyes water, and the cornea is rendered opaque. Vomiting, racking coughs, and a sense of suffocation and temporary blindness are common. In larger amounts exposure can kill the cells of the cornea, producing permanent blindness.

It can also bring about emphysema, asthma, bronchitis, pneumonia, and other respiratory ailments.

Heavy exposure can cause death by suffocating spasms of the bronchial tubes carrying air to the lungs, or by drowning as body fluids released by the irritating gas accumulate in the lungs. Because of the danger of suffocation, the chances of ill effects increase if one runs when MIC is present in the atmosphere, as running increases the oxygen requirement. ...

[Long-term effects may be] lung, kidney, liver, and eye damage, because MIC destroys protein in the blood stream; the kidneys and liver become overworked trying to rid the body of these aberrant wastes. It can lead to keratitis and corneal ulcers which could cause opacity of the cornea.

Now let's see what air pollution effects had actually been reported in the days, months and years that followed the Bhopal tragedy.

Acute reactions to gas inhalation in the immediate wake of the gas leakage (Ref. 21):

Long-term health effects (Ref. 23).

And what about animals - how did they react to such overwhelming doses of pollution?

It shouldn't be surprising to suggest that animals had suffered just as much as people.

Reports published several months after the gas leak claim that as many as 2,000 commercial cows, buffaloes, goats and horses as well as thousands of stray dogs, cats and birds died immediately. (Ref. 24)

Vegetation surrounding the affected areas had also been badly affected. People were even warned about eating locally grown vegetables as many plants showed signs of genetic damage. (Ref. 25)

Water & Soil Pollution Effects of Bhopal Gas Leakage

While water & soil pollution - which still plague the site and surrounding areas of the Union Carbide plant in Bhopal - had not been a direct consequence of the 1984 gas leakage, it is hard not to think about it as an integral part of this pollution saga.

Here is what Jack Laurenson reports as of 2011 (Ref. 26):

Although it was the release of toxic gas that drew worldwide attention to Bhopal, Union Carbide had been openly dumping its highly toxic waste in the surrounding areas for years, and water and soil contaminated with chemicals and heavy metals continues to claim lives. Entire communities suffer with painful, debilitating illnesses. ...

Greenpeace and other organisations, including the CSE, have found high concentrations of chlorobenzenes and volatile and semi-volatile organochlorines, as well as metals such as chromium, copper, nickel, lead, zinc and mercury in the local water and soil.

Mercury concentrations seven million times higher than the World Health Organization's recommended limits have been recorded, and all of the water pumps in the area have been found to be heavily contaminated with toxins and metals.

There are reports that more than 350 tons of toxic waste are still scattered around the site and continue to pollute the soil and groundwater in the area which leads to cancer, congenital defects, immunity problems and many other conditions. (Ref. 27)

What is even more shocking is the fact that concentrations of some toxins continue to rise as they seep through the soil and straight into the groundwater. In spite of that, residents have to use their local groundwater supplies due to the lack of any better alternatives. (Ref. 28)

One of the most troubling effects of water and soil pollution in the affected area of Bhopal is of course the presence of high concentrations of poisons in the breast milk of lactating women (ref. 29), since this invariably implies long-term health problems for the breast-fed babies.

While we cannot list all the adverse effects of this specific case, we'll try to summarize common Effects of Heavy Metals Pollution of water and soil - of which we have general knowledge - and which we can reasonably expect to find in Bhopal as well.

General Effects of Heavy Metals Pollution Found In Water & Soil

Heavy metals pollution has been called "potentially one of the most serious forms of aquatic pollution" (ref. 30), and for a very good reason.

A study conducted by Greenpeace in 1999 identified a large number of toxic heavy metals still found in high concentrations at the Union Carbide factory site including soil & groundwater supplies.

Some of these heavy metals are: mercury, lead, cadmium, chromium, copper, nickel, zinc. (Ref. 31)

Most of them are present in the environment in different forms. We look at the effects of the harmful forms of these chemicals (ex., methyl mercury).

As we already mentioned above, these are common effects of these chemicals that we are aware of from scientific studies on a variety of other pollution cases.

So let's summarize health-related effects of the above-mentioned metals found in water and soil. (Ref. 32)

Environmental Pollution - Conclusion

Environmental pollution is causing a lot of distress not only to humans but also animals, driving many animal species to endangerment and even extinction.

The transboundary nature of environmental pollution makes it even more difficult to manage it – you cannot build brick walls along the borders of your country or put customs cabins at every point of entry to regulate its flows into your country.

Everything on our planet is interconnected, and while the nature supplies us with valuable environmental services without which we cannot exist, we all depend on each other’s actions and the way we treat natural resources.

It’s widely recognised that we are hugely overspending our current budget of natural resources – at the existing rates of its exploitation, there is no way for the environment to recover in good time and continue “performing” well in the future.

Perhaps we should adopt a holistic view of nature – it is not an entity that exists separately from us; the nature is us, we are an inalienable part of it, and we should care for it in the most appropriate manner. Only then can we possibly solve the problem of environmental pollution.

Written by:            Irina Gray of Tropical-Rainforest-Animals.com

First published in:    April 2008

Updates:               December 2011