Growing evidence of local and global pollution and an increasingly informed public over time have given rise to environmentalism and the environmental movement , which generally seek to limit human impact on the environment. The major forms of pollution are listed below along with the particular contaminant relevant to each of them:. A pollutant is a waste material that pollutes air, water, or soil. Three factors determine the severity of a pollutant: its chemical nature, the concentration and the persistence. Pollution has a cost. A manufacturing activity that causes air pollution is an example of a negative externality in production.
Because responsibility or consequence for self-directed action lies partly outside the self, an element of externalization is involved. If there are external benefits, such as in public safety , less of the good may be produced than would be the case if the producer were to receive payment for the external benefits to others. However, goods and services that involve negative externalities in production, such as those that produce pollution, tend to be over-produced and underpriced since the externality is not being priced into the market.
Pollution can also create costs for the firms producing the pollution. Sometimes firms choose, or are forced by regulation, to reduce the amount of pollution that they are producing. The associated costs of doing this are called abatement costs, or marginal abatement costs if measured by each additional unit. Society derives some indirect utility from pollution, otherwise there would be no incentive to pollute. This utility comes from the consumption of goods and services that create pollution. Therefore, it is important that policymakers attempt to balance these indirect benefits with the costs of pollution in order to achieve an efficient outcome.
It is possible to use environmental economics to determine which level of pollution is deemed the social optimum. At this point the damage of one extra unit of pollution to society, the marginal cost of pollution, is exactly equal to the marginal benefit of consuming one more unit of the good or service. In markets with pollution, or other negative externalities in production, the free market equilibrium will not account for the costs of pollution on society. If the social costs of pollution are higher than the private costs incurred by the firm, then the true supply curve will be higher.
The point at which the social marginal cost and market demand intersect gives the socially optimal level of pollution. At this point, the quantity will be lower and the price will be higher in comparison to the free market equilibrium. This model can be used as a basis to evaluate different methods of internalizing the externality. Some examples include tariffs , a carbon tax and cap and trade systems. Air pollution comes from both natural and human-made anthropogenic sources. However, globally human-made pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.
Motor vehicle emissions are one of the leading causes of air pollution. Principal stationary pollution sources include chemical plants , coal-fired power plants , oil refineries ,  petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms dairy cows, pigs, poultry, etc. Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicides .
About million metric tons of hazardous wastes are generated each year. In February , a report by the Intergovernmental Panel on Climate Change IPCC , representing the work of 2, scientists, economists, and policymakers from more than countries, said that humans have been the primary cause of global warming since Humans have ways to cut greenhouse gas emissions and avoid the consequences of global warming, a major climate report concluded. But to change the climate, the transition from fossil fuels like coal and oil needs to occur within decades, according to the final report this year from the UN's Intergovernmental Panel on Climate Change IPCC.
Some of the more common soil contaminants are chlorinated hydrocarbons CFH , heavy metals such as chromium , cadmium — found in rechargeable batteries , and lead — found in lead paint , aviation fuel and still in some countries, gasoline , MTBE , zinc , arsenic and benzene. In a series of press reports culminating in a book called Fateful Harvest unveiled a widespread practice of recycling industrial byproducts into fertilizer, resulting in the contamination of the soil with various metals.
Ordinary municipal landfills are the source of many chemical substances entering the soil environment and often groundwater , emanating from the wide variety of refuse accepted, especially substances illegally discarded there, or from pre landfills that may have been subject to little control in the U.
There have also been some unusual releases of polychlorinated dibenzodioxins , commonly called dioxins for simplicity, such as TCDD. Pollution can also be the consequence of a natural disaster. For example, hurricanes often involve water contamination from sewage, and petrochemical spills from ruptured boats or automobiles.
Larger scale and environmental damage is not uncommon when coastal oil rigs or refineries are involved. Some sources of pollution, such as nuclear power plants or oil tankers , can produce widespread and potentially hazardous releases when accidents occur. In the case of noise pollution the dominant source class is the motor vehicle , producing about ninety percent of all unwanted noise worldwide. Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory disease , cardiovascular disease , throat inflammation, chest pain, and congestion.
Water pollution causes approximately 14, deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. An estimated million Indians have no access to a proper toilet,   Over ten million people in India fell ill with waterborne illnesses in , and 1, people died, most of them children. Oil spills can cause skin irritations and rashes. Noise pollution induces hearing loss , high blood pressure , stress , and sleep disturbance. Mercury has been linked to developmental deficits in children and neurologic symptoms.
Older people are majorly exposed to diseases induced by air pollution. Those with heart or lung disorders are at additional risk. Children and infants are also at serious risk. Lead and other heavy metals have been shown to cause neurological problems.
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Chemical and radioactive substances can cause cancer and as well as birth defects. An October study by the Lancet Commission on Pollution and Health found that global pollution, specifically toxic air, water, soils and workplaces, kill nine million people annually, which is triple the number of deaths caused by AIDS, tuberculosis and malaria combined, and 15 times higher than deaths caused by wars and other forms of human violence. Pollution has been found to be present widely in the environment. There are a number of effects of this:. This web site includes links to databases, bibliographies, tutorials, and other scientific and consumer-oriented resources.
A paper linked pollution to adverse school outcomes for children. A number of studies show that pollution has an adverse effect on the productivity of both indoor and outdoor workers.
An Introduction to Pollution Science
To protect the environment from the adverse effects of pollution, many nations worldwide have enacted legislation to regulate various types of pollution as well as to mitigate the adverse effects of pollution. Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil.
Without pollution control, the waste products from overconsumption , heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control.
In the field of land development , low impact development is a similar technique for the prevention of urban runoff. The earliest precursor of pollution generated by life forms would have been a natural function of their existence. The attendant consequences on viability and population levels fell within the sphere of natural selection.
These would have included the demise of a population locally or ultimately, species extinction. Processes that were untenable would have resulted in a new balance brought about by changes and adaptations. At the extremes, for any form of life, consideration of pollution is superseded by that of survival.
For humankind, the factor of technology is a distinguishing and critical consideration, both as an enabler and an additional source of byproducts. Short of survival, human concerns include the range from quality of life to health hazards. Since science holds experimental demonstration to be definitive, modern treatment of toxicity or environmental harm involves defining a level at which an effect is observable.
Common examples of fields where practical measurement is crucial include automobile emissions control , industrial exposure e. LD 50 , and medicine e. But it assumes that the dilutant is in virtually unlimited supply for the application or that resulting dilutions are acceptable in all cases. Such simple treatment for environmental pollution on a wider scale might have had greater merit in earlier centuries when physical survival was often the highest imperative, human population and densities were lower, technologies were simpler and their byproducts more benign.
But these are often no longer the case. Furthermore, advances have enabled measurement of concentrations not possible before. The use of statistical methods in evaluating outcomes has given currency to the principle of probable harm in cases where assessment is warranted but resorting to deterministic models is impractical or infeasible. In addition, consideration of the environment beyond direct impact on human beings has gained prominence.
Yet in the absence of a superseding principle, this older approach predominates practices throughout the world. It is the basis by which to gauge concentrations of effluent for legal release, exceeding which penalties are assessed or restrictions applied. One such superseding principle is contained in modern hazardous waste laws in developed countries, as the process of diluting hazardous waste to make it non-hazardous is usually a regulated treatment process. Carbon dioxide , while vital for photosynthesis , is sometimes referred to as pollution, because raised levels of the gas in the atmosphere are affecting the Earth's climate.
Disruption of the environment can also highlight the connection between areas of pollution that would normally be classified separately, such as those of water and air. Recent studies have investigated the potential for long-term rising levels of atmospheric carbon dioxide to cause slight but critical increases in the acidity of ocean waters , and the possible effects of this on marine ecosystems.
The Pure Earth , an international non-for-profit organization dedicated to eliminating life-threatening pollution in the developing world, issues an annual list of some of the world's most polluting industries. A report by the Institute for Agriculture and Trade Policy and GRAIN says that the meat and dairy industries are poised to surpass the oil industry as the world's worst polluters. Pure Earth issues an annual list of some of the world's worst polluted places.
From Wikipedia, the free encyclopedia. For other uses, see Pollution disambiguation. For the academic journal, see Environmental Pollution journal. Introduction of contaminants that cause adverse change. Main article: Pollutant. Play media. Main article: Regulation and monitoring of pollution.
Main article: Global warming. Retrieved Retrieved 1 December The Guardian. Retrieved October 20, Bibcode : Sci United States Environmental Protection Agency. Diefendorf; Kurkpatrick Dorsey University of Pittsburgh Press.
American Meteorological Society. The Environmental Blog. Archived from the original on Bulletin of the Atomic Scientists. Bibcode : BuAtS.. Science Advances. Bibcode : SciA Public finance and public policy 4th ed. New York: Worth Publishers. Environmental economics 2nd ed. Water pollution has many different causes and this is one of the reasons why it is such a difficult problem to solve. With billions of people on the planet, disposing of sewage waste is a major problem.
According to figures from the World Health Organization the most recent available at the time this article was updated in , some 2.
Sewage disposal affects people's immediate environments and leads to water-related illnesses such as diarrhea that kills , children under five each year. In developed countries, most people have flush toilets that take sewage waste quickly and hygienically away from their homes. Yet the problem of sewage disposal does not end there. When you flush the toilet, the waste has to go somewhere and, even after it leaves the sewage treatment works, there is still waste to dispose of.
Sometimes sewage waste is pumped untreated into the sea. Until the early s, around 5 million tons of sewage was dumped by barge from New York City each year. In early , it was reported that the tiny island of Guernsey between Britain and France has decided to continue dumping 16, tons of raw sewage into the sea each day. In theory, sewage is a completely natural substance that should be broken down harmlessly in the environment: 90 percent of sewage is water. When people are sick with viruses, the sewage they produce carries those viruses into the environment.
It is possible to catch illnesses such as hepatitis, typhoid, and cholera from river and sea water. Photo: During crop-spraying, some chemicals will drain into the soil. Eventually, they seep into rivers and other watercourses. Suitably treated and used in moderate quantities, sewage can be a fertilizer: it returns important nutrients to the environment, such as nitrogen and phosphorus, which plants and animals need for growth.
The trouble is, sewage is often released in much greater quantities than the natural environment can cope with. Chemical fertilizers used by farmers also add nutrients to the soil, which drain into rivers and seas and add to the fertilizing effect of the sewage. Together, sewage and fertilizers can cause a massive increase in the growth of algae or plankton that overwhelms huge areas of oceans, lakes, or rivers. This is known as a harmful algal bloom also known as an HAB or red tide, because it can turn the water red. It is harmful because it removes oxygen from the water that kills other forms of life, leading to what is known as a dead zone.
The Gulf of Mexico has one of the world's most spectacular dead zones. Each summer, according to studies by the NOAA , it grows to an area of around — square miles 14,—15, square kilometers , which is about the same size as the state of Connecticut. A few statistics illustrate the scale of the problem that waste water chemicals washed down drains and discharged from factories can cause. Around half of all ocean pollution is caused by sewage and waste water. Each year, the world generates perhaps 5—10 billion tons of industrial waste, much of which is pumped untreated into rivers, oceans, and other waterways.
However, there have been major improvements in waste water treatment recently. Factories are point sources of water pollution, but quite a lot of water is polluted by ordinary people from nonpoint sources; this is how ordinary water becomes waste water in the first place. Virtually everyone pours chemicals of one sort or another down their drains or toilets. Even detergents used in washing machines and dishwashers eventually end up in our rivers and oceans. So do the pesticides we use on our gardens. A lot of toxic pollution also enters waste water from highway runoff. Highways are typically covered with a cocktail of toxic chemicals—everything from spilled fuel and brake fluids to bits of worn tires themselves made from chemical additives and exhaust emissions.
When it rains, these chemicals wash into drains and rivers. It is not unusual for heavy summer rainstorms to wash toxic chemicals into rivers in such concentrations that they kill large numbers of fish overnight. It has been estimated that, in one year, the highway runoff from a single large city leaks as much oil into our water environment as a typical tanker spill. Some highway runoff runs away into drains; others can pollute groundwater or accumulate in the land next to a road, making it increasingly toxic as the years go by. Detergents are relatively mild substances.
At the opposite end of the spectrum are highly toxic chemicals such as polychlorinated biphenyls PCBs. They were once widely used to manufacture electronic circuit boards , but their harmful effects have now been recognized and their use is highly restricted in many countries. Nevertheless, an estimated half million tons of PCBs were discharged into the environment during the 20th century.
They were carried there through the oceans, thousands of miles from where they originally entered the environment. Although PCBs are widely banned, their effects will be felt for many decades because they last a long time in the environment without breaking down. Another kind of toxic pollution comes from heavy metals , such as lead , cadmium, and mercury. Lead was once commonly used in gasoline petrol , though its use is now restricted in some countries.
Mercury and cadmium are still used in batteries though some brands now use other metals instead. Until recently, a highly toxic chemical called tributyltin TBT was used in paints to protect boats from the ravaging effects of the oceans. Ironically, however, TBT was gradually recognized as a pollutant: boats painted with it were doing as much damage to the oceans as the oceans were doing to the boats. The best known example of heavy metal pollution in the oceans took place in when a Japanese factory discharged a significant amount of mercury metal into Minamata Bay, contaminating the fish stocks there.
It took a decade for the problem to come to light. By that time, many local people had eaten the fish and around were poisoned. Hundreds of people were left dead or disabled. People view radioactive waste with great alarm—and for good reason. At high enough concentrations it can kill; in lower concentrations it can cause cancers and other illnesses. The biggest sources of radioactive pollution in Europe are two factories that reprocess waste fuel from nuclear power plants : Sellafield on the north-west coast of Britain and Cap La Hague on the north coast of France.
Both discharge radioactive waste water into the sea, which ocean currents then carry around the world. Countries such as Norway, which lie downstream from Britain, receive significant doses of radioactive pollution from Sellafield. The Norwegian government has repeatedly complained that Sellafield has increased radiation levels along its coast by 6—10 times. Both the Irish and Norwegian governments continue to press for the plant's closure.
Photo: Oil-tanker spills are the most spectacular forms of pollution and the ones that catch public attention, but only a fraction of all water pollution happens this way. When we think of ocean pollution, huge black oil slicks often spring to mind, yet these spectacular accidents represent only a tiny fraction of all the pollution entering our oceans.
Even considering oil by itself, tanker spills are not as significant as they might seem: only 12 percent of the oil that enters the oceans comes from tanker accidents; over 70 percent of oil pollution at sea comes from routine shipping and from the oil people pour down drains on land. The biggest oil spill in recent years and the biggest ever spill in US waters occurred when the tanker Exxon Valdez broke up in Prince William Sound in Alaska in Around 12 million gallons 44 million liters of oil were released into the pristine wilderness—enough to fill your living room times over!
Estimates of the marine animals killed in the spill vary from approximately sea otters and 34, birds to as many as sea otters and , sea birds. Several billion salmon and herring eggs are also believed to have been destroyed. If you've ever taken part in a community beach clean, you'll know that plastic is far and away the most common substance that washes up with the waves. There are three reasons for this: plastic is one of the most common materials, used for making virtually every kind of manufactured object from clothing to automobile parts; plastic is light and floats easily so it can travel enormous distances across the oceans; most plastics are not biodegradable they do not break down naturally in the environment , which means that things like plastic bottle tops can survive in the marine environment for a long time.
A plastic bottle can survive an estimated years in the ocean and plastic fishing line can last up to years. While plastics are not toxic in quite the same way as poisonous chemicals, they nevertheless present a major hazard to seabirds, fish, and other marine creatures. For example, plastic fishing lines and other debris can strangle or choke fish. This is sometimes called ghost fishing.
River Pollution - Environmental Science - Oxford Bibliographies
About half of all the world's seabird species are known to have eaten plastic residues. In one study of shearwaters in the North Pacific, over 80 percent of the birds were found to contain plastic residues in their stomachs.
In the early s, marine scientist Tim Benton collected debris from a 2km 1. His study recorded approximately a thousand pieces of garbage including pieces of plastic, 71 plastic bottles, and two dolls heads. Today, much media attention focuses on the Great Pacific Garbage Patch , a floating, oceanic graveyard of plastic junk roughly three times the size of France, discovered by sailor Charles J.
Moore in But, as you'll know well enough if you've ever taken part in a community beach clean, persistent plastic litters every ocean on the planet: some 8 million tons of new plastic are dumped in the sea every single year. Most people's idea of water pollution involves things like sewage, toxic metals, or oil slicks, but pollution can be biological as well as chemical. In some parts of the world, alien species are a major problem. Alien species sometimes known as invasive species are animals or plants from one region that have been introduced into a different ecosystem where they do not belong.
Outside their normal environment, they have no natural predators, so they rapidly run wild, crowding out the usual animals or plants that thrive there. Common examples of alien species include zebra mussels in the Great Lakes of the USA, which were carried there from Europe by ballast water waste water flushed from ships.
The Mediterranean Sea has been invaded by a kind of alien algae called Caulerpa taxifolia. In the Black Sea, an alien jellyfish called Mnemiopsis leidyi reduced fish stocks by 90 percent after arriving in ballast water. In San Francisco Bay, Asian clams called Potamocorbula amurensis, also introduced by ballast water, have dramatically altered the ecosystem.
Photo: Invasive species: Above: Water hyacinth crowding out a waterway around an old fence post. Photo by Steve Hillebrand. Below: Non-native zebra mussels clumped on a native mussel. These are the most common forms of pollution—but by no means the only ones. Heat or thermal pollution from factories and power plants also causes problems in rivers.
By raising the temperature, it reduces the amount of oxygen dissolved in the water, thus also reducing the level of aquatic life that the river can support. Another type of pollution involves the disruption of sediments fine-grained powders that flow from rivers into the sea. Dams built for hydroelectric power or water reservoirs can reduce the sediment flow.
This reduces the formation of beaches, increases coastal erosion the natural destruction of cliffs by the sea , and reduces the flow of nutrients from rivers into seas potentially reducing coastal fish stocks. Increased sediments can also present a problem. During construction work, soil, rock, and other fine powders sometimes enters nearby rivers in large quantities, causing it to become turbid muddy or silted. The extra sediment can block the gills of fish, effectively suffocating them.
Construction firms often now take precautions to prevent this kind of pollution from happening. Some people believe pollution is an inescapable result of human activity: they argue that if we want to have factories, cities, ships, cars, oil, and coastal resorts, some degree of pollution is almost certain to result. In other words, pollution is a necessary evil that people must put up with if they want to make progress. Fortunately, not everyone agrees with this view. One reason people have woken up to the problem of pollution is that it brings costs of its own that undermine any economic benefits that come about by polluting.
Take oil spills, for example. They can happen if tankers are too poorly built to survive accidents at sea. But the economic benefit of compromising on tanker quality brings an economic cost when an oil spill occurs. The oil can wash up on nearby beaches, devastate the ecosystem, and severely affect tourism. The main problem is that the people who bear the cost of the spill typically a small coastal community are not the people who caused the problem in the first place the people who operate the tanker.
Yet, arguably, everyone who puts gasoline petrol into their car—or uses almost any kind of petroleum-fueled transport—contributes to the problem in some way. So oil spills are a problem for everyone, not just people who live by the coast and tanker operates. Sewage is another good example of how pollution can affect us all. Sewage discharged into coastal waters can wash up on beaches and cause a health hazard. People who bathe or surf in the water can fall ill if they swallow polluted water—yet sewage can have other harmful effects too: it can poison shellfish such as cockles and mussels that grow near the shore.
People who eat poisoned shellfish risk suffering from an acute—and sometimes fatal—illness called paralytic shellfish poisoning. Shellfish is no longer caught along many shores because it is simply too polluted with sewage or toxic chemical wastes that have discharged from the land nearby. Pollution matters because it harms the environment on which people depend. The environment is not something distant and separate from our lives. It's not a pretty shoreline hundreds of miles from our homes or a wilderness landscape that we see only on TV.
The environment is everything that surrounds us that gives us life and health. Destroying the environment ultimately reduces the quality of our own lives—and that, most selfishly, is why pollution should matter to all of us. There is no easy way to solve water pollution; if there were, it wouldn't be so much of a problem. Broadly speaking, there are three different things that can help to tackle the problem—education, laws, and economics—and they work together as a team. Making people aware of the problem is the first step to solving it.
In the early s, when surfers in Britain grew tired of catching illnesses from water polluted with sewage, they formed a group called Surfers Against Sewage to force governments and water companies to clean up their act. People who've grown tired of walking the world's polluted beaches often band together to organize community beach-cleaning sessions.
Anglers who no longer catch so many fish have campaigned for tougher penalties against factories that pour pollution into our rivers. Greater public awareness can make a positive difference. One of the biggest problems with water pollution is its transboundary nature. Many rivers cross countries, while seas span whole continents. Pollution discharged by factories in one country with poor environmental standards can cause problems in neighboring nations, even when they have tougher laws and higher standards.
Environmental laws can make it tougher for people to pollute, but to be really effective they have to operate across national and international borders. The European Union has water-protection laws known as directives that apply to all of its member states. They include the Bathing Water Directive updated , which seeks to ensure the quality of the waters that people use for recreation. Most countries also have their own water pollution laws. Most environmental experts agree that the best way to tackle pollution is through something called the polluter pays principle.
This means that whoever causes pollution should have to pay to clean it up, one way or another. Polluter pays can operate in all kinds of ways. It could mean that tanker owners should have to take out insurance that covers the cost of oil spill cleanups, for example.
It could also mean that shoppers should have to pay for their plastic grocery bags, as is now common in Ireland, to encourage recycling and minimize waste. Or it could mean that factories that use rivers must have their water inlet pipes downstream of their effluent outflow pipes, so if they cause pollution they themselves are the first people to suffer. Ultimately, the polluter pays principle is designed to deter people from polluting by making it less expensive for them to behave in an environmentally responsible way. Life is ultimately about choices—and so is pollution. We can live with sewage-strewn beaches, dead rivers, and fish that are too poisonous to eat.
Or we can work together to keep the environment clean so the plants, animals, and people who depend on it remain healthy. We can take individual action to help reduce water pollution, for example, by using environmentally friendly detergents , not pouring oil down drains, reducing pesticides, and so on.