PollutionFrom Wikipedia, the free encyclopediaJump to: navigation, search

Air pollution from World War II weapon production in AlabamaPollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms.[1] Pollution can take the form of chemical substances or energy, such as noise, heat, or light. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Pollution is often classed as point source or nonpoint source pollution. The Blacksmith Institute issues annually a list of the world's worst polluted places. In the 2007 issues the ten top nominees are located in Azerbaijan, China, India, Peru, Russia, Ukraine, and Zambia.[2]

Contents [hide]

1 Ancient cultures

2 Official acknowledgement

3 Modern awareness

4 Forms of pollution

5 Pollutants

6 Sources and causes

7 Effects

7.1 Human health

7.2 Environment

7.3 Environmental health information

8 Regulation and monitoring

9 Pollution control

9.1 Practices

9.2 Pollution control devices

10 Perspectives

11 Greenhouse gases and global warming

12 See also

13 References

14 External links

Ancient culturesAir pollution has always been with us. According to a 1983 article in the journal Science, "soot found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires."[3] The forging of metals appears to be a key turning point in the creation of significant air pollution levels outside the home. Core samples of glaciers in Greenland indicate increases in pollution associated with Greek, Roman and Chinese metal production.[4]

Official acknowledgementThe earliest known writings concerned with pollution were written between the 9th and 13th centuries by Persian scientists such as Muhammad ibn Zakarīya Rāzi (Rhazes), Ibn Sina (Avicenna), and al-Masihi or were Arabic medical treatises written by physicians such as al-Kindi (Alkindus), Qusta ibn Luqa (Costa ben Luca), Ibn Al-Jazzar, al-Tamimi, Ali ibn Ridwan, Ibn Jumay, Isaac Israeli ben Solomon, Abd-el-latif, Ibn al-Quff, and Ibn al-Nafis. Their works covered a number of subjects related to pollution such as air contamination, water contamination, soil contamination, solid waste mishandling, and environmental assessments of certain localities.[5]

King Edward I of England banned the burning of sea-coal by proclamation in London in 1272, after its smoke had become a problem.[6][7] But the fuel was so common in England that this earliest of names for it was acquired because it could be carted away from some shores by the wheelbarrow. Air pollution would continue to be a problem in England, especially later during the industrial revolution, and extending into the recent past with the Great Smog of 1952. This same city also recorded one of the earlier extreme cases of water quality problems with the Great Stink on the Thames of 1858, which led to construction of the London sewerage system soon afterward.

It was the industrial revolution that gave birth to environmental pollution as we know it today. The emergence of great factories and consumption of immense quantities of coal and other fossil fuels gave rise to unprecedented air pollution and the large volume of industrial chemical discharges added to the growing load of untreated human waste. Chicago and Cincinnati were the first two American cities to enact laws ensuring cleaner air in 1881. Other cities followed around the country until early in the 20th century, when the short lived Office of Air Pollution was created under the Department of the Interior. Extreme smog events were experienced by the cities of Los Angeles and Donora, Pennsylvania in the late 1940s, serving as another public reminder.[8]

Modern awarenessPollution became a popular issue after World War II, due to radioactive fallout from atomic warfare and testing. Then a non-nuclear event, The Great Smog of 1952 in London, killed at least 4000 people.[9] This prompted some of the first major modern environmental legislation, The Clean Air Act of 1956.

Pollution began to draw major public attention in the United States between the mid-1950s and early 1970s, when Congress passed the Noise Control Act, the Clean Air Act, the Clean Water Act and the National Environmental Policy Act.

Bad bouts of local pollution helped increase consciousness. PCB dumping in the Hudson River resulted in a ban by the EPA on consumption of its fish in 1974. Long-term dioxin contamination at Love Canal starting in 1947 became a national news story in 1978 and led to the Superfund legislation of 1980. Legal proceedings in the 1990s helped bring to light Chromium-6 releases in California--the champions of whose victims became famous. The pollution of industrial land gave rise to the name brownfield, a term now common in city planning. DDT was banned in most of the developed world after the publication of Rachel Carson's Silent Spring.

The development of nuclear science introduced radioactive contamination, which can remain lethally radioactive for hundreds of thousands of years. Lake Karachay, named by the Worldwatch Institute as the "most polluted spot" on earth, served as a disposal site for the Soviet Union thoroughout the 1950s and 1960s. Second place may go to the area of Chelyabinsk U.S.S.R. (see reference below) as the "Most polluted place on the planet".[citation needed]

Nuclear weapons continued to be tested in the Cold War, sometimes near inhabited areas, especially in the earlier stages of their development. The toll on the worst-affected populations and the growth since then in understanding about the critical threat to human health posed by radioactivity has also been a prohibitive complication associated with nuclear power. Though extreme care is practiced in that industry, the potential for disaster suggested by incidents such as those at Three Mile Island and Chernobyl pose a lingering specter of public mistrust. One legacy of nuclear testing before most forms were banned has been significantly raised levels of background radiation.[citation needed]

International catastrophes such as the wreck of the Amoco Cadiz oil tanker off the coast of Brittany in 1978 and the Bhopal disaster in 1984 have demonstrated the universality of such events and the scale on which efforts to address them needed to engage. The borderless nature of atmosphere and oceans inevitably resulted in the implication of pollution on a planetary level with the issue of global warming. Most recently the term persistent organic pollutant (POP) has come to describe a group of chemicals such as PBDEs and PFCs among others. Though their effects remain somewhat less well understood owing to a lack of experimental data, they have been detected in various ecological habitats far removed from industrial activity such as the Arctic, demonstrating diffusion and bioaccumulation after only a relatively brief period of widespread use.

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.

Forms of pollution

The Lachine Canal in Montreal Canada, is polluted.The major forms of pollution are listed below along with the particular pollutants relevant to each of them:

Air pollution, the release of chemicals and particulates into the atmosphere. Common gaseous air pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM10 to PM2.5.

Light pollution, includes light trespass, over-illumination and astronomical interference.

Littering

Noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.

Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE,[10] herbicides, pesticides and chlorinated hydrocarbons.

Radioactive contamination, resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment. (See alpha emitters and actinides in the environment.)

Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.

Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.

Water pollution, by the release of waste products and contaminants into surface runoff into river drainage systems, leaching into groundwater, liquid spills, wastewater discharges, eutrophication and littering.

PollutantsMain article: Pollutant

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.

Sources and causesAir pollution comes from both natural and man made sources. Though globally man made pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.[11]

Motor vehicle emissions are one of the leading causes of air pollution.[12][13][14] China, United States, Russia, Mexico, and Japan are the world leaders in air pollution emissions. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries,[15] petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms (dairy cows, pigs, poultry, etc.), PVC factories, metals production factories, plastics factories, and other heavy industry. Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicides[16]

About 400 million metric tons of hazardous wastes are generated each year.[17] The United States alone produces about 250 million metric tons.[18] Americans constitute less than 5% of the world's population, but produce roughly 25% of the world’s CO2,[19] and generate approximately 30% of world’s waste.[20][21] In 2007, China has overtaken the United States as the world's biggest producer of CO2.[22]

In February 2007, a report by the Intergovernmental Panel on Climate Change (IPCC), representing the work of 2,500 scientists from more than 130 countries, said that humans have been the primary cause of global warming since 1950. Humans have ways to cut greenhouse gas emissions and avoid the consequences of global warming, a major climate report concluded. But in order 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).[23]

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 2001 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-1970 landfills that may have been subject to little control in the U.S. or EU. There have also been some unusual releases of polychlorinated dibenzodioxins, commonly called dioxins for simplicity, such as TCDD.[24]

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.

EffectsHuman health

Overview of main health effects on humans from some common types of pollution.[25][26][27]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 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrhoeal sickness every day.[28] Nearly 500 million Chinese lack access to safe drinking water.[29] 656,000 people die prematurely each year in China because of air pollution. In India, air pollution is believed to cause 527,700 fatalities a year.[30] Studies have estimated that the number of people killed annually in the US could be over 50,000.[31]

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 under additional risk. Children and infants are also at serious risk. Lead and other heavy metals have been shown to cause neurological problems. Chemical and radioactive substances can cause cancer and as well as birth defects.

EnvironmentPollution has been found to be present widely in the environment. There are a number of effects of this:

Biomagnification describes situations where toxins (such as heavy metals) may pass through trophic levels, becoming exponentially more concentrated in the process.

Carbon dioxide emissions cause ocean acidification, the ongoing decrease in the pH of the Earth's oceans as CO2 becomes dissolved.

The emission of greenhouse gases leads to global warming which affects ecosystems in many ways.

Invasive species can out compete native species and reduce biodiversity. Invasive plants can contribute debris and biomolecules (allelopathy) that can alter soil and chemical compositions of an environment, often reducing native species competitiveness.

Nitrogen oxides are removed from the air by rain and fertilise land which can change the species composition of ecosystems.

Smog and haze can reduce the amount of sunlight received by plants to carry out photosynthesis and leads to the production of tropospheric ozone which damages plants.

Soil can become infertile and unsuitable for plants. This will affect other organisms in the food web.

Sulphur dioxide and nitrogen oxides can cause acid rain which lowers the pH value of soil.

Environmental health informationThe Toxicology and Environmental Health Information Program (TEHIP)[32] at the United States National Library of Medicine (NLM) maintains a comprehensive toxicology and environmental health web site that includes access to resources produced by TEHIP and by other government agencies and organizations. This web site includes links to databases, bibliographies, tutorials, and other scientific and consumer-oriented resources. TEHIP also is responsible for the Toxicology Data Network (TOXNET®)[33] an integrated system of toxicology and environmental health databases that are available free of charge on the web.

TOXMAP is a Geographic Information System (GIS) that is part of TOXNET. TOXMAP uses maps of the United States to help users visually explore data from the United States Environmental Protection Agency's (EPA) Toxics Release Inventory and Superfund Basic Research Programs.

Regulation and monitoringMain article: Regulation and monitoring of pollution

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 controlPollution 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 consumption, 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.

Practicesrecycling

Pollution control devicesDust collection systems

Baghouses

Cyclones

Electrostatic precipitators

Scrubbers

Baffle spray scrubber

Cyclonic spray scrubber

Ejector venturi scrubber

Mechanically aided scrubber

Spray tower

Wet scrubber

Sewage treatment

Activated sludge biotreaters

API oil-water separators[15][34]

Biofilters

Dissolved air flotation (DAF)

Powdered activated carbon treatment

Sedimentation (water treatment)

Vapor recovery systems

PerspectivesThe 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.g. Occupational Safety and Health Administration (OSHA) PELs), toxicology (e.g. LD50), and medicine (e.g. medication and radiation doses).

"The solution to pollution is dilution", is a dictum which summarizes a traditional approach to pollution management whereby sufficiently diluted pollution is not harmful.[35][36] It is well-suited to some other modern, locally scoped applications such as laboratory safety procedure and hazardous material release emergency management. 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 unfeasible. 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. The regressive cases are those where a controlled level of release is too high or, if enforceable, is neglected. Migration from pollution dilution to elimination in many cases is confronted by challenging economical and technological barriers.

Greenhouse gases and global warmingMain article: Global warming

Historical and projected CO2 emissions by country.

Source: Energy Information Administration.[37][38]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.

See alsoEnvironmental health

Hazardous Substances Data Bank

Environment portal

Book: Pollution

Wikipedia Books are collections of articles that can be downloaded or ordered in print.

Air pollution

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Air dispersion modeling

Arden Pope

Atmospheric Chemistry Observational Databases - links to freely available data.

Climate change

Emission standard

Greenhouse gas

Soil contamination

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Environmental soil science

List of solid waste treatment technologies

List of waste management companies

List of waste management topics

Water pollution

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Cruise ship pollution

Marine debris

Marine pollution

Ship pollution

Stormwater

Wastewater

Wastewater quality indicators

Other

--------------------------------------------------------------------------------

Contamination control

Earth Day

Externality

Genetic pollution

Global warming

Heat pollution

List of environmental issues

Noise health effects

References1.^ "Pollution - Definition from the Merriam-Webster Online Dictionary". Merriam-webster.com. 2010-08-13. http://www.merriam-webster.com/dictionary/pollution. Retrieved 2010-08-26.

2.^ The World's most polluted places, Blcksmith Institute - September 2007

3.^ Spengler, John D. and Sexton, Ken (1983) "Indoor Air Pollution: A Public Health Perspective" Science (New Series) 221(4605 ): pp. 9-17, page 9

4.^ Hong, Sungmin et al. (1996) "History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice" Science (New Series) 272(5259): pp. 246-249, page 248

5.^ L. Gari (2002), "Arabic Treatises on Environmental Pollution up to the End of the Thirteenth Century", Environment and History 8 (4), pp. 475-488.

6.^ David Urbinato (Summer 1994). "London's Historic "Pea-Soupers"". United States Environmental Protection Agency. http://www.epa.gov/history/topics/perspect/london.htm. Retrieved 2006-08-02.

7.^ "Deadly Smog". PBS. 2003-01-17. http://www.pbs.org/now/science/smog.html. Retrieved 2006-08-02.

8.^ James R. Fleming; Bethany R. Knorr of Colby College. "History of the Clean Air Act". American Meteorological Society. http://www.ametsoc.org/sloan/cleanair/. Retrieved 2006-02-14.

9.^ 1952: London fog clears after days of chaos (BBC News)

10.^ Concerns about MTBE from U.S. EPA website

11.^ Declaration of the United Nations Conference on the Human Environment, 1972

12.^ Environmental Performance Report 2001 (Transport, Canada website page)

13.^ State of the Environment, Issue: Air Quality (Australian Government website page)

14.^ Pollution and Society Marisa Buchanan and Carl Horwitz, University of Michigan

15.^ a b Beychok, Milton R. (1967). Aqueous Wastes from Petroleum and Petrochemical Plants (1st ed.). John Wiley & Sons. LCCN 67019834. ISBN 0471071897.

16.^ Silent Spring, R Carlson, 1962

17.^ "Pollution". Microsoft Encarta Online Encyclopedia 2009.

18.^ "Chapter 23 – Solid, Toxic, and Hazardous Waste"

19.^ "Revolutionary CO2 maps zoom in on greenhouse gas sources". Purdue University. April 7, 2008.

20.^ "Waste Watcher" (PDF). http://www.oregon.gov/DAS/FAC/docs/ww092001.pdf. Retrieved 2010-08-26.

21.^ Alarm sounds on US population boom. August 31, 2006. The Boston Globe.

22.^ "China overtakes US as world's biggest CO2 emitter". Guardian.co.uk. June 19, 2007.

23.^ "Global Warming Can Be Stopped, World Climate Experts Say". News.nationalgeographic.com. http://news.nationalgeographic.com/news/2007/05/070504-global-warming.html. Retrieved 2010-08-26.

24.^ Beychok, Milton R. (January 1987). "A data base for dioxin and furan emissions from refuse incinerators". Atmospheric Environment 21 (1): 29–36. doi:10.1016/0004-6981(87)90267-8.

25.^ World Resources Institute: August 2008 Monthly Update: Air Pollution's Causes, Consequences and Solutions Submitted by Matt Kallman on Wed, 2008-08-20 18:22. Retrieved on April 17, 2009

26.^ waterhealthconnection.org Overview of Waterborne Disease Trends] By Patricia L. Meinhardt, MD, MPH, MA, Author. Retrieved on April 16, 2009

27.^ Pennsylvania State University > Potential Health Effects of Pesticides. by Eric S. Lorenz. 2007.

28.^ "A special report on India: Creaking, groaning: Infrastructure is India’s biggest handicap". The Economist. 11 December 2008. http://www.economist.com/specialreports/displaystory.cfm?story_id=12749787.

29.^ "As China Roars, Pollution Reaches Deadly Extremes". The New York Times. August 26, 2007.

30.^ Chinese Air Pollution Deadliest in World, Report Says. National Geographic News. July 9, 2007.

31.^ David, Michael, and Caroline. "Air Pollution - Effects". Library.thinkquest.org. http://library.thinkquest.org/26026/Environmental_Problems/air_pollution_-_effects.html. Retrieved 2010-08-26.

32.^ "SIS.nlm.nih.gov". SIS.nlm.nih.gov. 2010-08-12. http://sis.nlm.nih.gov/enviro.html. Retrieved 2010-08-26.

33.^ "Toxnet.nlm.nih.gov". Toxnet.nlm.nih.gov. http://toxnet.nlm.nih.gov/. Retrieved 2010-08-26.

34.^ American Petroleum Institute (API) (February 1990). Management of Water Discharges: Design and Operations of Oil-Water Separators (1st ed.). American Petroleum Institute.

35.^ Gershon Cohen Ph.D.. "The 'Solution' to Pollution Is Still 'Dilution'". Earth Island Institute. http://www.earthisland.org/eijournal/new_articles.cfm?articleID=299&journalID=49. Retrieved 2006-02-14. [dead link]

36.^ "What is required". Clean Ocean Foundation. 2001. http://www.cleanocean.org/index_general.asp?menuid=240.010. Retrieved 2006-02-14.

37.^ World Carbon Dioxide Emissions (Table 1, Report DOE/EIA-0573, 2004, Energy Information Administration)

38.^ Carbon dioxide emissions chart (graph on Mongabay website page based on Energy Information Administration's tabulated data)

External links Wikimedia Commons has media related to: Pollution

Look up pollution in Wiktionary, the free dictionary.

OEHHA proposition 65 list

OSHA limits for air contaminants

National Toxicology Program - from USA National Institutes of Health. Reports and studies on how pollutants affect people

TOXNET - NIH databases and reports on toxicology

TOXMAP - Geographic Information System (GIS) that uses maps of the United States to help users visually explore data from the United States Environmental Protection Agency (EPA) Toxics Release Inventory and Superfund Basic Research Programs

EPA.gov - manages Superfund sites and the pollutants in them (CERCLA). Map the EPA Superfund

Toxic Release Inventory - tracks how much waste USA companies release into the water and air. Gives permits for releasing specific quantities of these pollutants each year. Map EPA's Toxic Release Inventory

Agency for Toxic Substances and Disease Registry - Top 20 pollutants, how they affect people, what USA industries use them and the products in which they are found

Toxicology Tutorials from the National Library of Medicine - resources to review human toxicology.

Pollution Information from, Woods Hole Oceanographic Institution

World's Worst Polluted Places 2007, according to the Blacksmith Institute

The World's Most Polluted Places at Time.com (a division of Time Magazine)

Chelyabinsk: The Most Contaminated Spot on the Planet Documentary Film by Slawomir Grünberg (1996)

Kids' Lower IQ Scores Linked To Prenatal Pollution by Lindsey Tanner, The Huffington Post, July 20, 2009

Nieman Reports. Tracking Toxics When the Data Are Polluted

[hide]v · d · ePollution

Air pollution Acid rain · Air Quality Index · Atmospheric dispersion modeling · Chlorofluorocarbon · Global dimming · Global distillation · Global warming · Indoor air quality · Ozone depletion · Particulate · Smog

Water pollution Eutrophication · Hypoxia · Environmental monitoring · Freshwater environmental quality parameters · Marine pollution · Marine debris · Ocean acidification · Oil spill · Pharmaceuticals and personal care products · Ship pollution · Surface runoff · Thermal pollution · Urban runoff · Wastewater · Waterborne diseases · Water quality · Water stagnation

Soil contamination Bioremediation · Electrical resistance heating · Herbicide · Pesticide · Soil Guideline Values (SGVs)

Radioactive contamination Actinides in the environment · Environmental radioactivity · Fission product · Nuclear fallout · Plutonium in the environment · Radiation poisoning · Radium in the environment · Uranium in the environment

Other types of pollution Light pollution · Noise pollution · Radio spectrum pollution · Visual pollution

Inter-government treaties Montreal Protocol · Kyoto Protocol · CLRTAP · OSPAR · Stockholm Convention

Major organizations DEFRA · Environment Agency (England and Wales) · Scottish Environment Protection Agency (Scotland) · U.S. EPA · EEA · Greenpeace

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Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere.

The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.

Indoor air pollution and urban air quality are listed as two of the world's worst pollution problems in the 2008 Blacksmith Institute World's Worst Polluted Places report.[1]

Contents [hide]

1 Pollutants

2 Sources

2.1 Emission factors

3 Indoor air quality (IAQ)

4 Health effects

4.1 Effects on cystic fibrosis

4.2 Effects on COPD

4.3 Effects on children

4.4 Health effects in relatively "clean" areas

5 Reduction efforts

5.1 Control devices

6 Legal regulations

7 Cities

8 Carbon dioxide emissions

9 Atmospheric dispersion

10 Environmental impacts of greenhouse gas pollutants

11 See also

12 References

13 External links

[edit] PollutantsMain articles: Pollutant and Greenhouse gas

Before flue gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.

Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3) increased UV radiation, (4) acid rain, (5) increased ground level ozone concentration, (6) increased levels of nitrogen oxides.An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made.[2]

Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone — one of the many secondary pollutants that make up photochemical smog. Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.

About 4 percent of deaths in the United States can be attributed to air pollution, according to the Environmental Science Engineering Program at the Harvard School of Public Health.

Major primary pollutants produced by human activity include:

Sulfur oxides (SOx) - especially sulfur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain.[2] This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.

Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO2 is one of the most prominent air pollutants.

Carbon monoxide - is a colorless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.

Carbon dioxide (CO2) - a colorless, odorless, non-toxic greenhouse gas associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration

Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.

Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease,[3] altered lung function and lung cancer.

Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease.[4][5]

Toxic metals, such as lead, cadmium and copper.

Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.

Ammonia (NH3) - emitted from agricultural processes. Ammonia is a compound with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.

Odors — such as from garbage, sewage, and industrial processes

Radioactive pollutants - produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon.

Secondary pollutants include:

Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of air pollution; the word "smog" is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog.

Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere (it is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer). Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog.

Peroxyacetyl nitrate (PAN) - similarly formed from NOx and VOCs.

Minor air pollutants include:

A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.

A variety of persistent organic pollutants, which can attach to particulate matter.

Persistent organic pollutants (POPs) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have potential significant impacts on human health and the environment.

[edit] SourcesMain article: AP 42 Compilation of Air Pollutant Emission Factors

Dust storm approaching Stratford, Texas

Controlled burning of a field outside of Statesboro, Georgia in preparation for spring plantingSources of air pollution refer to the various locations, activities or factors which are responsible for the releasing of pollutants in the atmosphere. These sources can be classified into two major categories which are:

Anthropogenic sources (human activity) mostly related to burning different kinds of fuel

"Stationary Sources" include smoke stacks of power plants, manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices

"Mobile Sources" include motor vehicles, marine vessels, aircraft and the effect of sound etc.

Chemicals, dust and controlled burn practices in agriculture and forestry management. Controlled or prescribed burning is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters. Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest.

Fumes from paint, hair spray, varnish, aerosol sprays and other solvents

Waste deposition in landfills, which generate methane. Methane is not toxic; however, it is highly flammable and may form explosive mixtures with air. Methane is also an asphyxiant and may displace oxygen in an enclosed space. Asphyxia or suffocation may result if the oxygen concentration is reduced to below 19.5% by displacement

Military, such as nuclear weapons, toxic gases, germ warfare and rocketry

Natural sources

Dust from natural sources, usually large areas of land with little or no vegetation.

Methane, emitted by the digestion of food by animals, for example cattle.

Radon gas from radioactive decay within the Earth's crust. Radon is a colorless, odorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the second most frequent cause of lung cancer, after cigarette smoking.

Smoke and carbon monoxide from wildfires.

Vegetation, in some regions, emits environmentally significant amounts of VOCs on warmer days. These VOCs react with primary anthropogenic pollutants—specifically, NOx, SO2, and anthropogenic organic carbon compounds—to produce a seasonal haze of secondary pollutants.[6]

Volcanic activity, which produce sulfur, chlorine, and ash particulates.

[edit] Emission factorsMain article: AP 42 Compilation of Air Pollutant Emission Factors

Air pollutant emission factors are representative values that people attempt to relate the quantity of a pollutant released to the ambient air with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant (e.g., kilograms of particulate emitted per megagram of coal burned). Such factors facilitate estimation of emissions from various sources of air pollution. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally assumed to be representative of long-term averages.

The United States Environmental Protection Agency has published a compilation of air pollutant emission factors for a multitude of industrial sources.[7] The United Kingdom, Australia, Canada and many other countries have published similar compilations, as well as the European Environment Agency.[8][9][10][11][12]

[edit] Indoor air quality (IAQ)Main article: Indoor air quality

A lack of ventilation indoors concentrates air pollution where people often spend the majority of their time. Radon (Rn) gas, a carcinogen, is exuded from the Earth in certain locations and trapped inside houses. Building materials including carpeting and plywood emit formaldehyde (H2CO) gas. Paint and solvents give off volatile organic compounds (VOCs) as they dry. Lead paint can degenerate into dust and be inhaled. Intentional air pollution is introduced with the use of air fresheners, incense, and other scented items. Controlled wood fires in stoves and fireplaces can add significant amounts of smoke particulates into the air, inside and out.[13] Indoor pollution fatalities may be caused by using pesticides and other chemical sprays indoors without proper ventilation.

Carbon monoxide (CO) poisoning and fatalities are often caused by faulty vents and chimneys, or by the burning of charcoal indoors. Chronic carbon monoxide poisoning can result even from poorly adjusted pilot lights. Traps are built into all domestic plumbing to keep sewer gas, hydrogen sulfide, out of interiors. Clothing emits tetrachloroethylene, or other dry cleaning fluids, for days after dry cleaning.

Though its use has now been banned in many countries, the extensive use of asbestos in industrial and domestic environments in the past has left a potentially very dangerous material in many localities. Asbestosis is a chronic inflammatory medical condition affecting the tissue of the lungs. It occurs after long-term, heavy exposure to asbestos from asbestos-containing materials in structures. Sufferers have severe dyspnea (shortness of breath) and are at an increased risk regarding several different types of lung cancer. As clear explanations are not always stressed in non-technical literature, care should be taken to distinguish between several forms of relevant diseases. According to the World Health Organisation (WHO)[dead link], these may defined as; asbestosis, lung cancer, and mesothelioma (generally a very rare form of cancer, when more widespread it is almost always associated with prolonged exposure to asbestos).

Biological sources of air pollution are also found indoors, as gases and airborne particulates. Pets produce dander, people produce dust from minute skin flakes and decomposed hair, dust mites in bedding, carpeting and furniture produce enzymes and micrometre-sized fecal droppings, inhabitants emit methane, mold forms in walls and generates mycotoxins and spores, air conditioning systems can incubate Legionnaires' disease and mold, and houseplants, soil and surrounding gardens can produce pollen, dust, and mold. Indoors, the lack of air circulation allows these airborne pollutants to accumulate more than they would otherwise occur in nature.

[edit] Health effectsThe World Health Organization states that 2.4 million people die each year from causes directly attributable to air pollution, with 1.5 million of these deaths attributable to indoor air pollution.[14] "Epidemiological studies suggest that more than 500,000 Americans die each year from cardiopulmonary disease linked to breathing fine particle air pollution. . ."[15] A study by the University of Birmingham has shown a strong correlation between pneumonia related deaths and air pollution from motor vehicles.[16] Worldwide more deaths per year are linked to air pollution than to automobile accidents.[citation needed] Published in 2005 suggests that 310,000 Europeans die from air pollution annually.[citation needed] Causes of deaths include aggravated asthma, emphysema, lung and heart diseases, and respiratory allergies.[citation needed] The US EPA estimates that a proposed set of changes in diesel engine technology (Tier 2) could result in 12,000 fewer premature mortalities, 15,000 fewer heart attacks, 6,000 fewer emergency room visits by children with asthma, and 8,900 fewer respiratory-related hospital admissions each year in the United States.[citation needed]

The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.[17] Leaked industrial vapors from the Union Carbide factory, belonging to Union Carbide, Inc., U.S.A., killed more than 25,000 people outright and injured anywhere from 150,000 to 600,000. The United Kingdom suffered its worst air pollution event when the December 4 Great Smog of 1952 formed over London. In six days more than 4,000 died, and 8,000 more died within the following months.[citation needed] An accidental leak of anthrax spores from a biological warfare laboratory in the former USSR in 1979 near Sverdlovsk is believed to have been the cause of hundreds of civilian deaths.[citation needed] The worst single incident of air pollution to occur in the United States of America occurred in Donora, Pennsylvania in late October, 1948, when 20 people died and over 7,000 were injured.[18]

The health effects caused by air pollution may include difficulty in breathing, wheezing, coughing and aggravation of existing respiratory and cardiac conditions. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and premature death. The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics.[citation needed]

A new economic study of the health impacts and associated costs of air pollution in the Los Angeles Basin and San Joaquin Valley of Southern California shows that more than 3800 people die prematurely (approximately 14 years earlier than normal) each year because air pollution levels violate federal standards. The number of annual premature deaths is considerably higher than the fatalities related to auto collisions in the same area, which average fewer than 2,000 per year.[19]

Diesel exhaust (DE) is a major contributor to combustion derived particulate matter air pollution. In several human experimental studies, using a well validated exposure chamber setup, DE has been linked to acute vascular dysfunction and increased thrombus formation.[20][21] This serves as a plausible mechanistic link between the previously described association between particulate matter air pollution and increased cardiovascular morbidity and mortality.

[edit] Effects on cystic fibrosisMain article: Cystic fibrosis

A study from around the years of 1999 to 2000, by the University of Washington, showed that patients near and around particulate matter air pollution had an increased risk of pulmonary exacerbations and decrease in lung function.[22] Patients were examined before the study for amounts of specific pollutants like Pseudomonas aeruginosa or Burkholderia cenocepacia as well as their socioeconomic standing. Participants involved in the study were located in the United States in close proximity to an Environmental Protection Agency.[clarification needed] During the time of the study 117 deaths were associated with air pollution. Many patients in the study lived in or near large metropolitan areas in order to be close to medical help. These same patients had higher level of pollutants found in their system because of more emissions in larger cities. As cystic fibrosis patients already suffer from decreased lung function, everyday pollutants such as smoke, emissions from automobiles, tobacco smoke and improper use of indoor heating devices could further compromise lung function.[23]

[edit] Effects on COPDMain article: Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) includes diseases such as chronic bronchitis, emphysema, and some forms of asthma.[24]

A study conducted in 1960-1961 in the wake of the Great Smog of 1952 compared 293 London residents with 477 residents of Gloucester, Peterborough, and Norwich, three towns with low reported death rates from chronic bronchitis. All subjects were male postal truck drivers aged 40 to 59. Compared to the subjects from the outlying towns, the London subjects exhibited more severe respiratory symptoms (including cough, phlegm, and dyspnea), reduced lung function (FEV1 and peak flow rate), and increased sputum production and purulence. The differences were more pronounced for subjects aged 50 to 59. The study controlled for age and smoking habits, so concluded that air pollution was the most likely cause of the observed differences.[25]

It is believed that much like cystic fibrosis, by living in a more urban environment serious health hazards become more apparent. Studies have shown that in urban areas patients suffer mucus hypersecretion, lower levels of lung function, and more self diagnosis of chronic bronchitis and emphysema.[26]

[edit] Effects on childrenCities around the world with high exposure to air pollutants have the possibility of children living within them to develop asthma, pneumonia and other lower respiratory infections as well as a low initial birth rate. Protective measures to ensure the youths' health are being taken in cities such as New Delhi, India where buses now use compressed natural gas to help eliminate the “pea-soup” smog.[27] Research by the World Health Organization shows there is the greatest concentration of particulate matter particles in countries with low economic world power and high poverty and population rates. Examples of these countries include Egypt, Sudan, Mongolia, and Indonesia. In the United States, the Clean Air Act was passed in 1970, however in 2002 at least 146 million Americans were living in non-attainment areas—regions in which the concentration of certain air pollutants exceeded federal standards.[28] Those pollutants are known as the criteria pollutants, and include ozone, particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead. Because children are outdoors more and have higher minute ventilation they are more susceptible to the dangers of air pollution.

[edit] Health effects in relatively "clean" areasEven in areas with relatively low levels of air pollution, public health effects can be significant and costly. This is because effects can occur at very low levels and a large number of people breathe in such pollutants. A 2005 scientific study for the British Columbia Lung Association showed that a small improvement in air quality (1% reduction of ambient PM2.5 and ozone concentrations) would produce a $29 million in annual savings in the Metro Vancouver region in 2010.[29] This finding is based on health valuation of lethal (death) and sub-lethal (illness) effects.

[edit] Reduction effortsThere are various air pollution control technologies and land use planning strategies available to reduce air pollution. At its most basic level land use planning is likely to involve zoning and transport infrastructure planning. In most developed countries, land use planning is an important part of social policy, ensuring that land is used efficiently for the benefit of the wider economy and population as well as to protect the environment.

Efforts to reduce pollution from mobile sources includes primary regulation (many developing countries have permissive regulations),[citation needed] expanding regulation to new sources (such as cruise and transport ships, farm equipment, and small gas-powered equipment such as lawn trimmers, chainsaws, and snowmobiles), increased fuel efficiency (such as through the use of hybrid vehicles), conversion to cleaner fuels (such as bioethanol, biodiesel, or conversion to electric vehicles).

[edit] Control devicesThe following items are commonly used as pollution control devices by industry or transportation devices. They can either destroy contaminants or remove them from an exhaust stream before it is emitted into the atmosphere.

Particulate control

Mechanical collectors (dust cyclones, multicyclones)

Electrostatic precipitators An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.

Baghouses Designed to handle heavy dust loads, a dust collector consists of a blower, dust filter, a filter-cleaning system, and a dust receptacle or dust removal system (distinguished from air cleaners which utilize disposable filters to remove the dust).

Particulate scrubbersWet scrubber is a form of pollution control technology. The term describes a variety of devices that use pollutants from a furnace flue gas or from other gas streams. In a wet scrubber, the polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the liquid, by forcing it through a pool of liquid, or by some other contact method, so as to remove the pollutants.

Scrubbers

Baffle spray scrubber

Cyclonic spray scrubber

Ejector venturi scrubber

Mechanically aided scrubber

Spray tower

Wet scrubber

NOx control

Low NOx burners

Selective catalytic reduction (SCR)

Selective non-catalytic reduction (SNCR)

NOx scrubbers

Exhaust gas recirculation

Catalytic converter (also for VOC control)

VOC abatement

Adsorption systems, such as activated carbon

Flares

Thermal oxidizers

Catalytic converters

Biofilters

Absorption (scrubbing)

Cryogenic condensers

Vapor recovery systems

Acid Gas/SO2 control

Wet scrubbers

Dry scrubbers

Flue gas desulfurization

Mercury control

Sorbent Injection Technology

Electro-Catalytic Oxidation (ECO)

K-Fuel

Dioxin and furan control

Miscellaneous associated equipment

Source capturing systems

Continuous emissions monitoring systems (CEMS)

[edit] Legal regulations

Smog in CairoIn general, there are two types of air quality standards. The first class of standards (such as the U.S. National Ambient Air Quality Standards) set maximum atmospheric concentrations for specific pollutants. Environmental agencies enact regulations which are intended to result in attainment of these target levels. The second class (such as the North American Air Quality Index) take the form of a scale with various thresholds, which is used to communicate to the public the relative risk of outdoor activity. The scale may or may not distinguish between different pollutants.

[edit] CitiesAir pollution is usually concentrated in densely populated metropolitan areas, especially in developing countries where environmental regulations are relatively lax or nonexistent. However, even populated areas in developed countries attain unhealthy levels of pollution.

[edit] Carbon dioxide emissionsMost Polluted World Cities by PM[30]

Particulate

matter,

μg/m³ (2004) City

169 Cairo, Egypt

150 Delhi, India

128 Kolkata, India (Calcutta)

125 Tianjin, China

123 Chongqing, China

109 Kanpur, India

109 Lucknow, India

104 Jakarta, Indonesia

101 Shenyang, China

Total CO2 emissions

Main article: List of countries by carbon dioxide emissions

Countries with the highest CO2 emissions

Country Carbon dioxide emissions per

year (106 Tons) (2006) Percentage of global total

China 6,103 21.5%

United States 5,752 20.2%

Russia 1,564 5.5%

India 1,510 5.3%

Japan 1293 4.6%

Germany 805 2.8%

United Kingdom 568 2.0%

Canada 544 1.9%

South Korea 475 1.7%

Italy 474 1.7%