For all defence aspirants major air pollutants sources & effects of human health
Major air pollutants
Particulate matter suspended in air are dust and soot released from the industrial chimney. Their size ranges from 0.001 to 500 micrometers (um) in diameter.
Major source of SPM (suspended particulate matter) are vehicles, power plants, construction activities, oil refinery ,railway yard, market place ,industries,etc.
These fine particulates can be inhaled deep into the lungs can cause breathing and respiratory symptoms, irritation, inflammations and pneumoconiosis- a disease of the lungs due to inhalation of dust, characterized by inflammation coughing, and fibrosis.
Fly ash is ejected mostly by thermal power plants as by –products of coal burning operations.
It may cause heavy metal pollution in water bodies.
Affective vegetation as a result of its direct deposition on leaf surfaces or indirectly through its deposition on soil.
Fly ash particles are oxide rich and consist of silica, alumina oxides of iron, calcium and magnesium and toxic heavy metals like lead, arsenic cobalt and copper.
It is present in petrol, diesel ,lead batteries, paints, hair dye products etc.
It can cause nervous system damage and digestive problems and ,in some cases, cause cancer.
Tetraethyl lead(TEL) is used as an anti-knock agent in petrol for smooth and easy running of vehicles.
The lead particles coming out from the exhaust pipes of vehicles is mixed with air. If inhaled it produces injurious effects on kidney and liver and interferes with development of red blood cells.
They create physiological, biochemical and developmental disorders in plants and also contribute towards reproductive failure in plants.
Nanoparticles are particle with dimensions comparable to 1/10 of a meter.
Major natural processes that release NPs in the atmosphere are forest fires,volcanic eruptions weathering dust storms from desert etc.
Carbon monoxide (CO)
Carbon monoxide (CO) is a colorless ,odorless ,tasteless and highly toxic gas that is slightly less dense than air. it is short lived (stay only few months) in the atmosphere.
It is produced from the exhaust of internal combustion engines and from incomplete combustion of various other fuels. Iron smelting also produce carbon monoxide as a byproduct.
World wide ,the largest source of carbon monoxide is natural in origin, due to photochemical reactions in the troposphere. Other natural source of CO include volcanoes, forest fires, and other forms of combustion.
Carbon dioxide (CO2)
Co2 is an asphyxiant gas( asphyxia-a condition arising when the body is deprived of oxygen, causing unconsciousness or death).
Carbon dioxide is an important greenhouse gas.
It is also a major cause of ocean acidification because it dissolves in water to form carbonic acid.
Ozone (o3) it occurs naturally in the stratosphere. Here it absorbs harmful ultraviolet rays of the sun. However, at the ground level, it is pollutant (greenhouse gas) with highly toxic effects.
Vehicles and industries are the major source of ground level ozone emissions. Carbon monoxide, nitrogen dioxide plays a major role in converting o2 to o3.
Nox is a genetic term for the various nitrogen oxides produced during combustion.
They are produced mainly in internal combustion engines and coal burning power plants. They are produced dioxide play a major role in converting o2 to o3
They are believed to aggravate asthmatic conditions and create many respiratory health issues, especially in children.nox emissions cause global cooling through the formation of –oh radicals that destroy methane molecules countering the effect of greenhouse gases.
Sulphur dioxide (SO2) it is a toxic gas with a pungent, irritating smell. It contributes to acid rain
It is released naturally by volcanic activity. It is abundantly available in the atmosphere of Venus.
It is primarily produced for sulfuric acid manufacture.
Inhaling dioxide is associated with increased respiratory symptoms and disease, difficulty in creating and premature death. It also weakens the functioning of certain nerves.
It is also produced by
Burning coal in thermal power plants and diesel fuels ;some industrial processes ,such as production of paper and smelting of metals.
Volatile organic compounds(VOCs)
Volatile organic compounds (VOCs) are a large group of carbon –based chemicals that easily evaporate at room temperature. for example, formaldehyde,
The main sources are perfumes, hair sprays, hair sprays, furniture polish, glues, air fresheners, moth repellents, wood preservatives, and other products.
Health effect-irritation of the eye, nose and throat, headaches, nausea and loss of coordination.
Long term-suspected to damage the liver.
Asbestos refers to a set of six naturally occurring silicate fibrous minerals-chrysolite ,crocidolite, amosite anthophyyllite, tremolite and actinolite.
It is known that prolonged inhalation of asbestors of asbestos fibers can cause serious and fatal illnesses including lung cancer,mesothelioma ,and asbestosis (a type of pneumoconiosis).
It is a gas that emitted naturally by the soil. Due to modern houses having poor ventilation, it is confirmed inside the house and causes lung cancers.
For more information for
go on the following links