Air
Pollution
Due to the
pollution ,the composition of the air is changing all over the world ,
especially in industrialised countries. Air pollution results from gaseous
emission from industry, thermal power stations , domestic composition etc. most
of the gaseous and particulate air pollutants are products of burning of fuels.
Burning of coal mainly produces carbon dioxide, sulphur dioxide and fly ash.
Lead ,carbon monoxide and nitrogen oxide are added to atmosphere from
automobiles exhaust.
Nitogen oxide
and sulphur dioxide together are responsible for acid rain . carbon monoxide is
highly toxic and impairs oxygen carrying capacity of blood . several cases of
death are reported every year from carbon monoxide poisoning from gas heater ,
heating device and coal mines. Lead which is emitted by automobiles is known to
hamper haemoglobin formation . compounds containing chlorine and fluorine ,
especially the chloroflourocarbons are widely used as propellants and as refrigerants
. they cause ozone depletion in stratosphere . air-bome solids and liquids
particulate are emitted by various industrial processes such as blasting ,
drilling, crushing , grinding and drying which may cause lungs diseases if
inhaled .
Haemoglobin is known to absorb NO2 more
easily than oxygen . about 80-90% NO2 inhale is easily absorb into the
bloodstream . this reduces the oxygen carrying capacity of blood . NO2 cause
lung tissue to become weaker and thus cause lungs cancer and emphysema ( breathing
problem due to breakdown of air sacs in the lungs , which then progressively
diminishes the ability of lungs to exchange oxygen and carbon dioxide in the
blood stream)
Thus , NO2
causes bronchitis and broncho- pneumonia . in the presence of sunlight , NO2
react with hydrocarbon to produce ozone, a highly toxic gas , known to cause
asthma .
