Short essay on Air pollution and Health

Medical climatology studies the relationship between human health and climate or weather. Even though the field of this branch of climatology is very comprehensive, effects of climate on diseases are not clearly understood.

However, it is every one’s knowledge that there are certain climatic factors which have harmful effects on human health, some of which result in illnesses and diseases such as, respiratory problems, rheumatic diseases, skin cancer and cardiovascular disorders.

Some of the local winds like the loo, cold wave, fohn, and sirocco are said to be the causes of irritability, depression, dizziness, hemorrhage and hypertension. However, here the discussion centers round the kinds of air pollution that has adverse effect on human health and comfort.

Air pollutants are many in number. They comprise various kinds of poisonous gases, liquids, inorganic as well as organic dusts, pollens, heat, light, noise, atmospheric disturbances and radioactivity. As we know, an undesirable concentration of any phenomenon in the air causes air pollution.

The effect of moderate pollution on health is not clearly known. But certain specific disasters produced by the abnormal concentrations as aforesaid merit attention. It is to be borne in mind that the infants, old and sickly persons are highly susceptible to air pollutants.

Chemical effluents and aerosols are responsible for causing irritation of eyes and mucous membranes, various types of respiratory ailments like asthma, bronchitis etc. There are many chemical effluents which pollute the air we breathe.

These pollutants are sulphur dioxide, nitrogen oxides, carbon monoxide, and different kinds of hydrocarbons. These pollutants cause different types of ailments. Sulphur dioxide, for example, has toxic effects through several mechanisms including interference with respiratory tract.

This pollutant is highly harmful to human health. High concentrations of the sulphur pollutants were responsible for the loss of human lives in several killer smokes. Human health is adversely affected when this pollutant (S0₂) is inhaled alone or in combination with fine aerosol particles.

This also affects the lungs and causes respiratory diseases like asthma, chronic bronchitis, reduced lung function and irritation of the respiratory tract. Nitric oxide and nitrogen dioxide are extremely toxic and are most harmful for human health. Nitrogen dioxide is a deadly poison and is one of the most dangerous gases. Its inhalation causes inflammation of the lung tissues.

Hydrogen sulphide (H₂S) is as toxic as cyanide, and its smell resembles that of rotten eggs. At low concentration it can cause headache, nausea, laziness, collapse, coma and death. It mixes very quickly with the human blood stream, and if inhaled at a concentration of 1000 PPM it may cause immediate death.

Chlorine, another toxic pollutant is found in large quantity in sea spray. Another source of chlorine is motor vehicle emission. Only in high concentrations chlorine is harmful to human health. Bromine exists in gaseous as well as solid form as a particulate. Its major source is the combustion of leaded petrol.

When automobile exhaust is exposed to sunlight, it produces smog. In addition, tropospheric ozone is also a serious threat to human health. It is irritating at higher concentration. Industrial processes and combustion of fossil fuels are other major anthropogenetic sources of aerosols (particulates) that are also toxic.

Transport air pollution by the use of motor vehicles has posed a serious threat to human beings and it is getting worse day by day in metropolitan cities of the world. New Delhi, the capital city of India, is one of the most polluted cities in the world.

Smoke emissions from diesel engines in particular pose serious threat to human health. It is undoubtedly true those motor vehicles in all the countries of the world cause air pollution more than any other man’s activity.

It is to be borne in mind that air pollution has no strict climatic boundaries. Its high concentrations develop in stable air when there is an inversion layer in the lower atmosphere.

In valleys and deep depressions inversion layer forms in the atmosphere near the ground. In the presence of inversion layer, the emissions from the motor vehicles are trapped between the base of the inversion layer and the ground.

Natural aeroallergens are closely related with weather and climate. Asthma and many other respiratory ailments are aggravated as pollens are spread to great distances by the wind.