Tag: environment and conservation

The increase in the concentration of the air pollutants results in an adverse effect on the plants and animal health. SO$ _2$ is considered as one of the pollutants which causes bleaching of the plants. The chlorophyll pigments in the leaves of the plants are destroyed in the presence of increased amounts of sulfuric acid which is formed by reacting with the water in plants. 

Ozone is a toxic gas which causes severe effects on the body on inhalation. The gas causes irritation in the nose, throat and other parts of the respiratory system. Inhalation of about 0.1 ppm of the gas may result in effects like swelling and bleeding of the lungs. Haemorrhage of the lungs, stomach and intestine is a common effect of the ozone breathing. 

Fuels burn when they react with oxygen in the air. If there is plenty of air, complete combustion happens.  Coal is mostly carbon. During complete combustion, carbon is oxidized to carbon dioxide:
carbon + oxygen -- carbon dioxide
If there is insufficient air for complete combustion, incomplete combustion (also called partial combustion)  happens. Hydrogen is still oxidized to water, but carbon monoxide forms instead of carbon dioxide.

A heat island is an area that is constantly warmer than surrounding areas. One of the reasons for the formation of heat island is air pollution. Other important reasons are changes in landscape due to the construction of buildings, roads, and other infrastructure which had replaced open land and vegetation. An island formation is the result of local changes in the environment brought about by urbanisation and release of polluting gases.

A major threat to Taj Mahal is from Mathura oil refinery due to polluting gases like sulphur dioxide, hydrogen sulphide and nitrogen oxides.  When moisture gets accumulated in polluted environment, the oxides of sulfur, carbon and nitrogen from weak sulfuric, carbonic and nitric acids which are corrosive of stone, metals, paints and textiles.  Many priceless works of art have suffered more damage in the last 20 years due to increased sulfur-dioxide in the atmosphere.

Leaves are directly exposed to air pollutants and effects of air pollution are first seen on leaves. Deposition of particulate matter hampers gaseous exchange and deposition of soot interfere with the capture of sunlight. Sulphur dioxide causes the destruction of chlorophyll and necrosis. Nitrogen oxides cause defoliation, necrosis, dieback and death of plants. Other than this, acid rain damages plant by a direct effect on foliage and growing points by chlorosis, necrosis, defoliation and dieback.

A thermal inversion takes place when a layer of warm air settles over a layer of cooler air that lies just above the ground. The warm air holds down the cool air and prevents pollutants from rising and scattering.

Inhalation of SO$ _2$ irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulphur dioxide are felt just after 10-15 min of inhalation.