air, noise and soil pollution

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Air pollution

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]Pollutants

A substance in the air that can cause harm to humans and the environment is known as an air pollutant. 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.

Major primary pollutants produced by human activity include:

Sulfur oxides (SOx) - especially sulphur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulphur 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 colourless, 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 colourless, 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 aerosolsthose made by human activitiescurrently 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]

HYPERLINK "http://en.wikipedia.org/wiki/Air_pollution" \l "cite_note-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.

Soil pollution Soil pollution usually results from different human activities, like waste dumping, use of agrochemicals, mining operations and urbanization.Waste DumpsLand gets dumping of industrial wastes, municipal wastes, medicals or hospital wastes. Industrial solid wastes and sludge are the major sources of Soil pollution by toxic organic and inorganic chemical compounds and heavy metals. The fall out from industrial emissions, for example the fly ash emitted by thermal power plants, can pollute surrounding lands. We must keep in mind that the particulates of the industrial emissions from the tall chimney always comes back to the earth surface sooner or later. Radioactive tests from nuclear testing laboratories and nuclear power plants and the radioactive fall out from the nuclear explosions also contaminate the soil. Radioactive materials thrive in the soil for long periods because they usually have a long half life. Stronium-90, for example, has a half life of 28 years, and the half life of Caesium-137 is 30 years.

Municipal Wastes: Municipal wastes mainly include domestic and kitchen wastes, market wastes, hospital wastes, livestock and poultry wastes, slaughterhouse wastes and waste metals, and glass and ceramic wastes, etc. Non-biodegradable materials like used polyethylene carry bags, waste plastic sheets, pet bottles etc. persist in soil for long periods. Hospital wastes contain organic materials, chemicals, metal needles, plastic and glass bottles, vials, etc. Dumping of domestic sewage and hospital organic wastes contaminate the environment with a variety of pathogens that can seriously affect human health. AgrochemicalsPesticides and weedicides are being increasingly applied to control pests and weeds in agricultural systems. Excess inorganic fertilizers and biocide residues are contaminating the soil as well as the surface and groundwater resources. Inorganic nutrients, like phosphate and nitrate are washed out to aquatic ecosystems and accelerate eutrophication there.Nitrate can also pollute drinking water. Inorganic fertilizers and pesticide residues change the chemical properties of soil and can adversely affect the soil organisms.

Mining operationsOpencast mining (a process where the surface of earth is dug open to bring out the underground mineral deposits) completely devastates the topsoil and contaminates the area with toxic metals and chemicals.

Control of soil pollutionControl measures for soil pollution and land degradation involve safer land use, planned urbanization, controlled developmental activities, safe disposal and managements of solid wastes from industries and human habitations. Management of solid wastes involves:

Collection and categorization of wastes. Recovery of resources like scar metals, plastics, etc. for recycling and reuse. Safe disposals with minimum environmental hazards.Sewage sludge and industrial solid wastes are used as landfills. Toxic chemicals and hazardous metal containing wastes are reused as bedding material for road construction. The fly ash bricks are also used for the similar purposes. Fly-ash bricks are also being used for building construction. Other notable methods to get rid of solid wastes are incineration (burning in presence of oxygen) and pyrolisis (combustion in the absence of oxygen). Municipal solid wastes containing biodegradable organic wastes, can be transformed to organic manure for agricultural purposes.

CausesThis type of contamination or pollution typically arises from the rupture of underground storage tanks, application of pesticides, percolation of contaminated surface water to subsurface strata, oil and fuel dumping, leaching of waste