Kid's Corner - Air Pollution
What is Air Pollution?
The presence in the atmosphere of one or more contaminants in such quality and for such duration as is injurious, or tends to be injurious, to human health or welfare, animal or plant life.' Air pollution is aggravated because of four developments: increasing traffic, growing cities, rapid economic development, and industrialization. Air pollution can cause health problems and it can also damage the environment and property.  Economic Losses Due to Air Pollution 
  • Direct medical losses
  • Lost income resulting from absenteeism from work 
  • Decreased productivity
  • Increased cost of cleaning
  • Losses due to damage to crops and ornamental vegetation
  • Decrease of property values

There are four important factor is causes for air pollution. They are, 

  • Increaing traffic and vehicle population 
  • Rapid growth of Population
  • Industrialization
  • Urbanization

Major air pollutants and their sources 

Carbon monoxide (CO) is a colourless, odorless gas that is produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood. 

Carbon dioxide (CO2) is the principle greenhouse gas emitted as a result of human activities such as the burning of coal, oil, and natural gases. 

Chloro floro carbons (CFC) are gases that are released mainly from air-conditioning systems and refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which leads to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun. 

Lead is present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects children in particular. It can cause nervous system damage and digestive problems and, in some cases, cause cancer. 

Ozone occur naturally in the upper layers of the atmosphere. This important gas shields the earth from the harmful ultraviolet rays of the sun. 

Nitrogen oxide (Nox) causes smog and acid rain. It is produced from burning fuels including petrol, diesel, and coal. Nitrogen oxides can make children susceptible to respiratory diseases in winters. 

Suspended particulate matter (SPM) consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods and is also the main source of haze which reduces visibility.

Sulphur dioxide (SO2) is a gas produced from burning coal, mainly in thermal power plants. Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide

Sources of air pollution 

Air pollutants consist of gaseous pollutants, odours, and SPM, (suspended particulate matter) such as dust, fumes, mist, and smoke. The concentration of these in and near the urban areas causes severe pollution to the surroundings. The largest sources of human-created air pollution are energy generation, transportation, and industries that use a great deal of energy sources.


Common atmospheric pollution sources and their pollutants 

Category Source Emitting Pollutants
Agriculture Open burning Suspended particulate matter, carbon monoxide, volatile organic compounds
Mining and quarrying  Coal mining; crude oil and gas production; stone quarrying Suspended particulate matter, sulphur dioxide, oxides of nitrogen, volatile organic compounds
Power generation Electricity; gas; steam Suspended particulate matter, sulphur dioxide, oxides of nitrogen, carbon monoxide, volatile organic compounds, sulphur trioxide, lead
Transport Combustion engines Suspended particulate matter, sulphur dioxide, oxides of nitrogen, carbon monoxide, volatile organic compounds, lead
Community service Municipal incinerators Suspended particulate matter, sulphur dioxide, oxides of nitrogen, carbon monoxide, volatile organic compounds, lead

Health impact of specific air pollutants

Some of these gases can seriously and adversely affect the health of the population and should be given due attention by the concerned authority. The gases mentioned below are mainly outdoor air pollutants but some of them can and do occur indoor depending on the source and the circumstances.

Pollutant Health Impact
Tobacco smoke. Tobacco smoke generates a wide range of harmful chemicals and is a major cause of ill health, as it is known to cause cancer, not only to the smoker but affecting passive smokers too. It is well-known that smoking affects the passive smoker (the person who is in the vicinity of a smoker and is not himself/herself a smoker) ranging from burning sensation in the eyes or nose, and throat irritation, to cancer, bronchitis, severe asthma, and a decrease in lung function.
Biological pollutants These are mostly allergens that can cause asthma, hay fever, and other allergic diseases.
Volatile organic compounds Volatile compounds can cause irritation of the eye, nose and throat. In severe cases there may be headaches, nausea, and loss of coordination. In the longer run, some of them are suspected to cause damage to the liver and other parts of the body.
Formaldehyde Exposure causes irritation to the eyes, nose and may cause allergies in some people
Lead Prolonged exposure can cause damage to the nervous system, digestive problems, and in some cases cause cancer. It is especially hazardous to small children.
Radon A radioactive gas that can accumulate inside the house, it originates from the rocks and soil under the house and its level is dominated by the outdoor air and also to some extent the other gases being emitted indoors. Exposure to this gas increases the risk of lung cancer.
Ozone Exposure to this gas makes our eyes itch, burn, and water and it has also been associated with increase in respiratory disorders such as asthma. It lowers our resistance to colds and pneumonia.
Oxides of nitrogen This gas can make children susceptible to respiratory diseases in the winters.
Carbon monoxide (CO) CO (carbon monoxide) combines with haemoglobin to lessen the amount of oxygen that enters our blood through our lungs. The binding with other haeme proteins causes changes in the function of the affected organs such as the brain and the cardiovascular system, and also the developing foetus. It can impair our concentration, slow our reflexes, and make us confused and sleepy.
Sulphur dioxide. (SO2)  Sulphur Dioxide in the air is caused due to the rise in combustion of fossil fuels. It can oxidize and form sulphuric acid mist. SO2 in the air leads to diseases of the lung and other lung disorders such as wheezing and shortness of breath. Long-term effects are more difficult to ascertain as SO2 exposure is often combined with that of SPM.
Suspended Particulate Matter SPM (suspended particulate matter). Suspended matter consists of dust, fumes, mist and smoke. The main chemical component of SPM that is of major concern is lead, others being nickel, arsenic, and those present in diesel exhaust. These particles when breathed in, lodge in our lung tissues and cause lung damage and respiratory problems. The importance of SPM as a major pollutant needs special emphasis as 
a) it affects more people globally than any other pollutant on a continuing basis; b) there is more monitoring data available on this than any other pollutant; and 
c) more epidemiological evidence has been collected on the exposure to this than to any other pollutant.


How to reduce to reduce the air pollution ?

  • Encourage your family to walk to the neighbourhood market.
  • Whenever possible take your bicycle.
  • As far as possible use public forms of transport.
  • Don't let your father drop you to school, take the school bus.
  • Encourage your family to form a car pool to office and back.
  • Reduce the use of aerosols in the household.
  • Look after the trees in your neighbourhood.
  • Begin a tree-watch group to ensure that they are well tended and cared for.
  • Switch-off all the lights and fans when not required.
  • If possible share your room with others when the airconditioner, cooler or fan is on.
  • Do not burn leaves in your garden, put them in a compost pit.
  • Make sure that the pollution check for your family car is done at regular intervals
  • Cars should, as far as possible, be fitted with catalytic converters.
  • Use only unleaded petrol.

Contents which are related with air pollution
Acid rain 
The term 'acid rain' refers to the acidification of rain associated with the combustion of fossil fuel: coal, oil and natural gas. Acid rain causes extensive damage to water, forest, soil resources and even human health. In the early 1980s acid rain become the favourite cause of doom. By 1986, the United Nations reported that 23 percent of all trees in Europe were moderated or severely by acid rain.
Ground-level ozone
Ground-level ozone is formed through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight. Ground-level ozone is especially harmful for seniors, children, asthmatics, and people with heart and lung conditions. It aggravates respiratory symptoms and further impairs the ability of these individuals to perform normal activities. It can inflame breathing passages, decreasing the lung's working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and dry out the protective membranes of the nose and throat and interfere with the body's ability to fight infection, increasing susceptibility to illness.
Indoor air pollution
In the developing countries, it is the rural areas that face the greatest threat from indoor pollution, where some 3.5 billion people continue to rely on traditional fuels such as firewood, charcoal, and cowdung for cooking and heating. Concentrations of indoor pollutants in households that burn traditional fuels are alarming. Burning such fuels produces large amount of smoke and other air pollutants in the confined space of the home, resulting in high exposure. Women and children are the groups most vulnerable as they spend more time indoors and are exposed to the smoke. In 1992, the World Bank designated indoor air pollution in the developing countries as one of the four most critical global environmental problems. Daily averages of pollutant level emitted indoors often exceed current WHO guidelines and acceptable levels. Although many hundreds of separate chemical agents have been identified in the smoke from biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic matter, and formaldehyde.
In urban areas, exposure to indoor air pollution has increased due to a variety of reasons, including the construction of more tightly sealed buildings, reduced ventilation, the use of synthetic materials for building and furnishing and the use of chemical products, pesticides, and household care products. Indoor air pollution can begin within the building or be drawn in from outdoors. Other than nitrogen dioxide, carbon monoxide, and lead, there are a number of other pollutants that affect the air quality in an enclosed space.


http://coe.mse.ac.in 2003-09. Madras School of Economics - Systems Department