PLASTIC AND POLLUTION

PLASTIC POLLUTION

Plastic is one of the chemical materials which is the biggest environmental hazard and is spreading all over the world causing pollution at larger scales. Polyethylene, polyvinyl chloride, polystyrene are  used in the manufacture process of plastics. Synthetic polymers are easily molded into complex shapes, have high chemical resistance, and are more or less elastic. they can be shaped into fibers and even thin transparent films. These properties  made them popular in making of durable or disposable goods and for packaging materials also. These materials have molecular weight ranging from several thousands to 1,50,000. Excessive molecular size is mainly responsible for their resistance  to bio-degradation and their persistence in soil environment for a long time.That s why they are big source of pollution. Plastic in the environment is polluting every where it is in seas and rivers causing water pollution and in dump places causing the air pollution, since the material is biologically quite inert. The plastic industry in the USA  is $ 50 billion per year and is obviously a good market for biotechnological enterprises.The Biotechnological processes are being developed as an alternative to  get new biodegradable bio-polymers . 20% of solid municipal wastes in US is plastic.and causing lot of pollution. Non-degradable plastics accumulate at the rate of 25 million tonnes per year. According to an estimate more than 100 million tonnes of plastic is produced every year all over the world. In India it is only 2 million tonnes. In India use of plastic is 2 kg per person per year while in European countries it is 60 kg per pe rson per year while that in US it is 80 kg per person per year.which is really alarming situation.To reduce this hazard of pollution we all have to work together.

plastics are made from remaining materials of petroleum refinery industry.What’s worse is that some plastics are made from the natural gas that is being used to heat home. It is turned into a disposable water bottle that will promptly be thrown away and will be a great hazard producing pollution specially producing water pollution .
Many plastic materials leak harmful chemicals into our food. #7 polycarbonate bottles are found to leach bis-phenol A (BPA), that has not only linked to pollution it is also linked to a wide array of health problems including hormone disruption, obesity and even cancer.Most annoying thing is that It’s used in baby bottles, some brands of reusable water bottles and as a lining for tin and aluminum cans.


Look for new containers and packaging made from a poly lactic acid (PLA) that can be made from a variety of plants, including potatoes, corn and sugar cane.PLA, or poly-lactic acid, a decomposable plastic is normally made from corn. It is made by converting corn into starch and starch into sugar. Microorganisms are used to gain  poly-lactic acid from that sugar.At  that point the PLA mixed with different starches forms into Styrofoam-like food containers, cups and  “plastic” bags. PLA is very safe in freezers, allergen free and, the       best    thing is, compo stable in just 30 to 45 days. So by using green technologies we can have pollution decreased.we should aim our selves to reduce pollution and safe our world and make future of our children a pollution free world.

WAR & POLLUTION

WAR MAKES POLLUTION AND HEAVY LIVES LOSS MORE PEOPLE DIED IN WARS AND VERY LESS DUE TO POLLUTION AND DISEASES PLEASE PLEASE ALWAYS CONDEMN WAR.

There are many areas of this world permanently damaged by pollution of weapons of war. And as going modern weapons are more deadly and producing more pollution. Depleted Uranium's being used to make shells heavy and more penetrating for more destruction yes it is making a big destruction both in life loss and air pollution. Its manufacturing companies claim it has no radioactive effects. However it has been used in Iraq and Kuwait (1991); Kosovo and Serbia 1999 there is a great rises in the rates of cancers and malformed births. Is this caused by chemical effects or residual radio activity? No-one knows as no research done yet.
So far the military did not admitted responsibility of being a big source of air pollution.
The US sprayed defoliating agents over Vietnam, Laos and Cambodia during the Vietnam war and this war also produced nothing but loss of lives at both sides and a large amount of air pollution also the water pollution. it also caused birth malformations and high rates of cancer,due to TCCD which was the main chemical - a hormone weedkiller. The purpose of this was to kill the rain forest, which very slowly grows. sufferers were not only the people who US wanted to suffer many of the US forces who were active in delivering  the chemicals, ate fish and animals from the affected areas, swum in the rivers and lake sand you know what happened next at least they caused the air pollution ,water pollution and what else is a question mark.Cluster bombs and Mines. Many of  major powers have agreed to ban  landmines, the US and England are using cluster bombs and not willing to ban it only because it kills.Cluster bomb is a single bomb containing many small bombs which are released on the first explosion. Many of these small bomb-lets do not explode of them and they remain unexploded like mines and so they kill both friends and foe,women and children every body what a shame.Children try to pick them up and it explodes. They can be active after many years of conflict even for tens of years. Mines can remain for many years, blowing off people's feet and legs.
Israel used them in :Lebanon in the war of July-August 2006 in Lebanon.

1) Can the UN force military's not to use chemicals and bio chemical weapons that have long-term health damages?
At least it is out of the UN agenda because US don't want to be banned at any criminal activity at least they are super power and they have right to kill any body in the world.
2) Did any body cleared the weapons used in the past?
So far the TCCD dropped in Vietnam are still there causing life threats and many forms of pollution. (3)Land should be abondend? Where the people will go? Is there any kind of serious research getting way of removing this material? Is there any microbiological method of getting out of it? We still hope so, but so far are just very few signs of success.we should all work together to get out of the war crisis and the pollution crisis also.Because war is a major source of causing water pollution and air pollution and most of all direct killing.

GLOBAL WARMING

GLOBAL WARMING

Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation.
The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005. The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic (man-made) greenhouse gas concentrations" via an enhanced greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward.
These basic conclusions have been endorsed by at least 30 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. While individual scientists have voiced disagreement with some findings of the IPCC,the overwhelming majority of scientists working on climate change agree with the IPCC's main conclusions.
Climate model projections summarized by the IPCC indicate that average global surface temperature will likely rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century. This range of values results from the use of differing scenarios of future greenhous gas emissions as well as models with differing climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a thousand years even if greenhouse gas levels are stabilized. The delay in reaching equilibrium is a result of the large heat capacity of the oceans.
Increasing global temperature is expected to cause sea levels to rise, an increase in the intensity of extreme weather events, and significant changes to the amount and pattern of precipitation, likely leading to an expanse of tropical areas and increased pace of desertification. Other expected effects of global warming include changes in agricultural yields, modifications of trade routes, glacier retreat, mass species extinctions and increases in the ranges of disease vectors.
Remaining scientific uncertainties include the amount of warming expected in the future, and how warming and related changes will vary from region to region around the globe. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions, but there is ongoing political and public debate worldwide regarding what, if any, action should be taken to reduce or reverse future warming or to adapt to its expected consequences.

CAUSES

The Earth's climate changes in response to external forcing, including variations in its orbit around the Sun (orbital forcing),changes in solar luminosity, volcanic eruptions,and atmospheric greenhouse gas concentrations. The detailed causes of the recent warming remain an active field of research, but the scientific consensus is that the increase in atmospheric greenhouse gases due to human activity caused most of the warming observed since the start of the industrial era. This attribution is clearest for the most recent 50 years, for which the most detailed data are available. Some other hypotheses departing from the consensus view have been suggested to explain most of the temperature increase. One such hypothesis proposes that warming may be the result of variations in solar activity.
None of the effects of forcing are instantaneous. The thermal inertia of the Earth's oceans and slow responses of other indirect effects mean that the Earth's current climate is not in equilibrium with the forcing imposed. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 °C (0.9 °F) would still occur

NOISE POLLUTION

NOISE POLLUTION

Noise pollution (or environmental noise) is displeasing human- or machine-created sound that disrupts the activity or balance of human or animal life. A common form of noise pollution is from transportation, principally motor vehicles.The word "noise" comes from the Latin word nausea meaning "seasickness", referring originally to nuisance noise

Sources of noise
See also: Roadway noise, Aircraft noise, and Noise measurement
The source of most noise worldwide is transportation systems, motor vehicle noise, but also including aircraft noise and rail noise.Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.
Other sources are car alarms, office equipment, factory machinery, construction work, groundskeeping equipment, barking dogs, appliances, power tools, lighting hum and audio entertainment systems.

Human health effects
Main article: Noise health effects
Noise health effects are both health and behavioural in nature. The unwanted sound is called noise. This unwanted sound can damage physiological and psychological health. Noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects.Furthermore, stress and hypertension are the leading causes to health problems, whereas tinnitus can lead to forgetfulness, severe depression and at times panic attacks.
Chronic exposure to noise may cause noise-induced hearing loss. Older males exposed to significant occupational noise demonstrate significantly reduced hearing sensitivity than their non-exposed peers, though differences in hearing sensitivity decrease with time and the two groups are indistinguishable by age 79.A comparison of Maaban tribesmen, who were insignificantly exposed to transportation or industrial noise, to a typical U.S. population showed that chronic exposure to moderately high levels of environmental noise contributes to hearing loss.
High noise levels can contribute to cardiovascular effects and exposure to moderately high levels during a single eight hour period causes a statistical rise in blood pressure of five to ten points and an increase in stress and vasoconstriction leading to the increased blood pressure noted above as well as to increased incidence of coronary artery disease.
Noise pollution is also a cause of annoyance. A 2005 study by Spanish researchers found that in urban areas households are willing to pay approximately four Euros per decibel per year for noise reduction.
Environmental effects
Noise can have a detrimental effect on animals by causing stress, increasing risk of mortality by changing the delicate balance in predator/prey detection and avoidance, and by interfering with their use of sounds in communication especially in relation to reproduction and in navigation. Acoustic overexposure can lead to temporary or permanent loss of hearing.
An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. One of the best known cases of damage caused by noise pollution is the death of certain species of beached whales, brought on by the loud sound of military sonar.
Noise also makes species communicate louder, which is called Lombard vocal response.Scientists and researchers have conducted experiments that show whales' song length is longer when submarine-detectors are on.If creatures don't "speak" loud enough, their voice will be masked by anthropogenic sounds. These unheard voices might be warnings, finding of prey, or preparations of net-bubbling. When one species begins speaking louder, it will mask other species' voice, causing the whole ecosystem to eventually speak louder.
Zebra finches become less faithful to their partners when exposed to traffic noise. This could alter a population's evolutionary trajectory by selecting traits, sapping resources normally devoted to other activities and thus lead to profound genetic and evolutionary consequences.

SULPHER & CFC's

Sulfur and chlorofluorocarbons (CFCs)
Sulfur dioxide is produced by combustion of sulfur-containing fuels, such as coal and fuel oils. Also, in the process of producing sulfuric acid and in metallurgical process involving ores that contain sulfur. Sulfur oxides can injure man, plants and materials. At sufficiently high concentrations, sulfur dioxide irritates the upper respiratory tract of human beings because potential effect of sulfur dioxide is to make breathing more difficult by causing the finer air tubes of the lung to constrict. "Power plants and factories emit 90% to 95% of the sulfur dioxide and 57% of the nitrogen oxides in the United States. Almost 60% of the SO2 emissions are released by tall smoke stakes, enabling the emissions to travel long distances". (Miller 494) As emissions of sulfur dioxide and nitric oxide from stationary sources are transported long distances by winds, they form secondary pollutants such as nitrogen dioxide, nitric acid vapor, and droplets containing solutions of sulfuric acid, sulfate, and nitrate salts. These chemicals descend to the earth's surface in wet form as rain or snow and in dry form as a gases fog, dew, or solid particles. This is known as acid deposition or acid rain.
Chlorofluorocarbons (CFCs)
CFCs are lowering the average concentration of ozone in the stratosphere. "Since 1978 the use of CFCs in aerosol cans has been banned in the United States, Canada, and most Scandinavian countries. Aerosols are still the largest use, accounting for 25% of global CFC use". (Miller 448) Spray cans, discarded or leaking refrigeration and air conditioning equipment, and the burning plastic foam products release the CFCs into the atmosphere. Depending on the type, CFCs stay in the atmosphere from 22 to 111 years. Chlorofluorocarbons move up to the stratosphere gradually over several decades. Under high energy ultra violet (UV) radiation, they break down and release chlorine atoms, which speed up the breakdown of ozone (O3) into oxygen gas (O2).
Chlorofluorocarbons, also known as Freons, are greenhouse gases that contribute to global warming. Photochemical air pollution is commonly referred to as "smog". Smog, a contraction of the words smoke and fog, has been caused throughout recorded history by water condensing on smoke particles, usually from burning coal. With the introduction of petroleum to replace coal economies in countries, photochemical smog has become predominant in many cities, which are located in sunny, warm, and dry climates with many motor vehicles. The worst episodes of photochemical smog tend to occur in summer.

CARBON DIOXIDE

Carbon Dioxide
Carbon dioxide (CO2) is one of the major pollutants in the atmosphere. Major sources of CO2 are fossil fuels burning and deforestation. "The concentrations of CO2 in the air around 1860 before the effects of industrialization were felt, is assumed to have been about 290 parts per million (ppm). In the hundred years and more since then, the concentration has increased by about 30 to 35 ppm that is by 10 percent". (Breuer 67) Industrial countries account for 65% of CO2 emissions with the United States and Soviet Union responsible for 50%. Less developed countries (LDCs), with 80% of the world's people, are responsible for 35% of CO2 emissions but may contribute 50% by 2020. "Carbon dioxide emissions are increasing by 4% a year". (Miller 450)
In 1975, 18 thousand million tons of carbon dioxide (equivalent to 5 thousand million tons of carbon) were released into the atmosphere, but the atmosphere showed an increase of only 8 billion tons (equivalent to 2.2 billion tons of carbon". (Breuer 70) The ocean waters contain about sixty times more CO2 than the atmosphere. If the equilibrium is disturbed by externally increasing the concentration of CO2 in the air, then the oceans would absorb more and more CO2. If the oceans can no longer keep pace, then more CO2 will remain into the atmosphere. As water warms, its ability to absorb CO2 is reduced.
CO2 is a good transmitter of sunlight, but partially restricts infrared radiation going back from the earth into space. This produces the so-called greenhouse effect that prevents a drastic cooling of the Earth during the night. Increasing the amount of CO2 in the atmosphere reinforces this effect and is expected to result in a warming of the Earth's surface. Currently carbon dioxide is responsible for 57% of the global warming trend. Nitrogen oxides contribute most of the atmospheric contaminants.

POLLUTION IN HOME

Air Pollution in the Home
You cannot escape air pollution, not even in your own home. "In 1985 the Environmental Protection Agency (EPA) reported that toxic chemicals found in the air of almost every American home are three times more likely to cause some type of cancer than outdoor air pollutants". (Miller 488) The health problems in these buildings are called "sick building syndrome". "An estimated one-fifth to one-third of all U.S. buildings are now considered "sick". (Miller 489) The EPA has found that the air in some office buildings is 100 times more polluted than the air outside. Poor ventilation causes about half of the indoor air pollution problems. The rest come from specific sources such as copying machines, electrical and telephone cables, mold and microbe-harboring air conditioning systems and ducts, cleaning fluids, cigarette smoke, carpet, latex caulk and paint, vinyl molding, linoleum tile, and building materials and furniture that emit air pollutants such as formaldehyde. A major indoor air pollutant is radon-222, a colorless, odorless, tasteless, naturally occurring radioactive gas produced by the radioactive decay of uranium-238. "According to studies by the EPA and the National Research Council, exposure to radon is second only to smoking as a cause of lung cancer". (Miller 489) Radon enters through pores and cracks in concrete when indoor air pressure is less than the pressure of gasses in the soil. Indoor air will be healthier than outdoor air if you use an energy recovery ventilator to provide a consistent supply of fresh filtered air and then seal air leaks in the shell of your home.

POLLUTIN & DISEASES

Air pollution is composed of many environmental factors. They include carbon monoxide, nitrates, sulfur dioxide, ozone, lead, secondhand tobacco smoke and particulate matter. Particulate matter, also known as particle pollution, is composed of solid and liquid particles within the air. It can be generated from vehicle emissions, tire fragmentation and road dust, power generation and industrial combustion, smelting and other metal processing, construction and demolition activities, residential wood burning, windblown soil, pollens, molds, forest fires, volcanic emissions and sea spray. These particles vary considerably in size, composition and origin.these are common disease's due to pollution.
Pulmonary Fibrosis
Cancer
Asthma
Alergy

NEW YORK, NAIROBI, GENEVA, 9 May (UNEP/UNICEF/WHO) -- Every day 5,500 children die from diseases caused by consuming water and food polluted with bacteria, according to a new study released by three United Nations agencies.
This alarming figure, from Children in the New Millennium: Environmental Impact on Health, shows that children the world over are the greatest victims of environmental degradation, despite the great strides made over the past 10 years in improving both children's well-being and the environment. The diseases largely influenced by this degradation, most notably diarrhoea and acute respiratory infections, are two of the leading causes of child mortality.

OZONE POLLUTION

OZONE POLLUTION



While exposure to ozone air pollution causes adverse health effects in most people, children are especially susceptible to these effects. Children spend significantly more time outdoors, especially in the summertime when ozone levels are the highest.
National statistics show that children spend an average of 50 percent more time outdoors than do adults.
A recent study conducted by the American Lung Association shows that as many as 27.1 million children age 13 and under, and over 1.9 million children with asthma are potentially exposed to unhealthful levels of ozone based on the new 0.08 ppm, eight-hour ozone level standard.
Minority children are disproportionately represented in areas with high ozone levels. Approximately 61.3% of black children, 69.2% of Hispanic children and 67.7% of Asian-American children live in areas that exceed the 0.08 ppm ozone standard, while only 50.8% of white children live in such areas.
Children spend more time engaged in vigorous activity (i.e., exercise). Such activity results in breathing in more air, and therefore more pollution being taken deep into the lungs. A California study found that children spend three times as much time engaged in sports and vigorous activities as adults do.
Children have a higher breathing rate than adults relative to their body weight and lung surface area. This results in a greater dose of pollution delivered to their lungs. Most biological air pollution damage is related to the dose of pollution inhaled in relation to the body weight and surface area of the target organ.
Even when children experience significant drops in lung function, they do not seem to suffer or report some of the acute symptoms, such as coughing, wheezing or shortness of breath, associated with ozone exposure in adults. Thus, children are not likely to receive or may not understand the biological warnings to reduce their ozone exposure by stopping their exercise or moving indoors.
Children have narrower airways than do adults. Thus, irritation or inflammation caused by air pollution that would produce only a slight response in an adult can result in a potentially significant obstruction of the airways in a young child.
During exercise, children, like adults, breathe with both their nose and mouth rather than just their noses. When the nose is bypassed during the breathing process, the filtering effects of the nose are lost, therefore allowing more air pollution to be inhaled.
Air pollution, including ozone, can result in more frequent respiratory infections in children due to impairment of the lung's ability to defend itself. Scientists are concerned that children who experience more frequent lower respiratory infections may be at greater risk of lower-than-normal lung function later in life.
When ozone levels are high, children should avoid calisthenics, soccer, running and other strenuous outdoor exercise. They should be encouraged to participate in less strenuous activities such as recreational swimming, swinging or indoor activities such as floor hockey and gymnastics instead.

SEA POLLUTION

SEA POLLUTION

By the year 2050 it is estimated that the world's population could have increased to around 9 billion. Of these, some 60 percent will live within 60km of the sea. The agricultural and industrial activities required to support this population will increase the already significant pressures on fertile coastal areas.
Pollution & the sea - like oil and waterOne significant impact of human activity upon the oceans is marine pollution. It is not just oil pollution from accidents and illegally discharged tank cleaning wastes. Despite the high visibility of oil spills upon marine environments the total quantities involved are dwarfed by those of pollutants introduced from other sources (including domestic sewage, industrial discharges, leakages from waste tips, urban and industrial run-off, accidents, spillage, explosions, sea dumping operations, oil production, mining, agriculture nutrients and pesticides, waste heat sources, and radioactive discharges).Land based sources are estimated to account for around 44 percent of the pollutants entering the sea and atmospheric inputs account for an estimated 33 percent. By contrast, maritime transport accounts only for around 12 percent.
Dawn of the dead: Creeping Dead ZonesThe impacts of pollution vary. Nutrient pollution from sewage discharges and agriculture can result in unsightly and possibly dangerous "blooms" of algae in coastal waters. As these blooms die and decay they use up the oxygen in the water. This has led, in some areas, to 'creeping dead zones' (CDZ), where oxygen dissolved in the water falls to levels unable to sustain marine life. Industrial pollution also contributes to these dead zones by discharging substances which, as they degrade, also use up the dissolved oxygen
Gone fissionRadioactive contamination in the sea has many causes. Historically the testing of nuclear weapons has contributed. The normal operation of nuclear power stations also pollute the sea, but by far the single biggest point-sources of man-made radioactive elements in the sea are the nuclear fuel reprocessing plants at La Hague in France and at Sellafield in the UK. These discharges have resulted in the widespread contamination of living marine resources over a wide area; radioactive elements traceable to reprocessing can be found in seaweeds as far away as the West Greenland Coast and along the coast of Norway
Toxic chemicalsThe input of man-made chemicals to the oceans potentially involves a huge number of different substances. 63,000 different chemicals are thought to be in use worldwide with 3000 accounting for 90 percent of the total production tonnage. Each year, anywhere up to 1000 new synthetic chemicals may be brought onto the market.Of all these chemicals some 4500 fall into the most serious category. These, known as persistent organic pollutants (POPs). They're resistant to breakdown and have the potential to accumulate in the tissues of living organisms (all marine life), causing hormone disruption which can, in turn, cause reproductive problems, induce cancer, suppress the immune system and interfere with normal development in children.POPs can also be transported long distances in the atmosphere and deposited in cold regions. As a result, Inuit populations who live in the Arctic a long distance from the sources of these pollutants are among the most heavily contaminated people on the planet, since they rely on fat-rich marine food sources such as fish and seals. POPs include the highly toxic dioxins and PCBs (Polychlorinated Biphenyls) together with various pesticides such as DDT and dieldrin. These chemicals are also thought to be responsible for some polar bear populations failing to reproduce normally.
Are you eating fish 'n' POPS tonight?Scarily, seafood consumed by people living in temperate regions are also affected by POPs. Oily fish tend to accumulate POPs in their bodies and these can be passed to human consumers. When oily fish are rendered down into fish meal and fish oils and subsequently used to feed other animals, then this too can act as a pathway to humans. Farmed fish and shellfish, dairy cattle, poultry and pigs are all fed fish meal in certain countries, and so meat and dairy products as well as farmed and wild fish can act as further sources of these chemicals to humans.
MiningTrace metal pollution from metal mining, production and processing industries can damage the health of marine plants and animals and render some seafood unfit for human consumption. The contribution of human activities can be very significant: the amount of mercury introduced to the environment by industrial activities is around four times the amount released through natural processes such as weathering and erosion.
OilThe most visible and familiar form of pollution is oil pollution caused by tanker accidents and tank washing at sea, and in addition to the gross visible short term impacts, severe long term problems can also result. In the case of the Exxon Valdez which ran aground in Alaska in 1989, biological impacts from the oil spill can still be identified 15 years after the event. The Prestige, which sank off the Spanish coast late in 2002, resulted in huge economic losses as it polluted more than 100 beaches in France and Spain and effectively destroyed the local fishing industry.

OUT DOOR POLLUTION

Outdoor Air Pollution

Sources of outdoor or ambient air pollution are varied and include both natural and man-made ones. Natural outdoor air pollution includes oxides of sulphur and nitrogen from volcanoes, oceans, biological decay, lightning strikes and forest fires, VOCs and pollen from plants, grasses and trees, and particulate matter from dust storms. Natural pollution is all around us all of the time. However, sometimes concentrations can increase dramatically, for example after a volcanic eruption, or at the beginning of the growing season.
Perhaps of more concern, given our ability to have greater control over its release to the atmosphere, are the man-made air pollutants, which can have a detrimental impact on ambient air quality. The most common source of man-made air pollution outdoors is the burning of fossil fuels, such as coal, oil and gas, in power stations, industries, homes and road vehicles. Depending on the nature of the fuel and the type of combustion process, pollutants released into the atmosphere from the burning of fossil fuels include nitrogen oxides, sulphur dioxide, carbon monoxide, particulate matter, lead and volatile organic compounds (VOCs). Other sources of these pollutants include forest burning, chemical, fertiliser and paper manufacture, and waste incineration. These pollutants are all called primary pollutants because they have direct sources. By contrast, there are no direct ground-level emissions of ozone to the atmosphere. Most ozone in the atmosphere near ground level is formed indirectly by the action of sunlight on VOCs in the presence of nitrogen dioxide, although a small amount comes from high up in the atmosphere where it forms naturally in the ozone layer. Ozone is a secondary ambient air pollutant.
Both primary and secondary pollutants are, to a greater or lesser extent, detrimental to human health, depending on their concentration in the air, and the sensitivity of the individual. Consequently, national and international legislation exists to regulate and control the amount of pollution emitted to the atmosphere, and to ensure that objectives for improving ambient air quality are achieved.

INDOOR AIR POLLUTION

Indoor air pollution and health

More than half of the world’s population rely on dung, wood, crop waste or coal to meet their most basic energy needs. Cooking and heating with such solid fuels on open fires or stoves without chimneys leads to indoor air pollution. This indoor smoke contains a range of health-damaging pollutants including small soot or dust particles that are able to penetrate deep into the lungs. In poorly ventilated dwellings, indoor smoke can exceed acceptable levels for small particles in outdoor air 100-fold. Exposure is particularly high among women and children, who spend the most time near the domestic hearth. Every year, indoor air pollution is responsible for the death of 1.6 million people - that's one death every 20 seconds.
The use of polluting fuels thus poses a major burden on the health of poor families in developing countries. The dependence on such fuels is both a cause and a result of poverty as poor households often do not have the resources to obtain cleaner, more efficient fuels and appliances. Reliance on simple household fuels and appliances can compromise health and thus hold back economic development, creating a vicious cycle of poverty.
According to the 2004 assessment of the International Energy Agency, the number of people relying on biomass fuels such as wood, dung and agricultural residues, for cooking and heating will continue to rise. In sub-Saharan Africa, the reliance on biomass fuels appears to be growing as a result of population growth and the unavailability of, or increases in the price of, alternatives such as kerosene and liquid petroleum gas. Despite the magnitude of this growing problem, the health impacts of exposure to indoor air pollution have yet to become a central focus of research, development aid and policy-making.