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2015-01-31T15:20:38+05:30

Air Pollution: Undesirable change : Undesirable change in the quality and composition of air.
 - How  it is caused?
  Burning of fossil fuels releases harmful oxides of sulphur, nitrogen and carbon along Burning of fossil fuels releases harmful oxides of sulphur, nitrogen and carbon along with hydro carbons . 

 - What it causes? 
 >Oxides on dissolving with atmospheric water give rise to acid and hence acid rain
 > Suspended hydrocarbons form smog (smoke+fog) hence, reduced visibility and smog (smoke+fog) hence, reduced visibility and economic activities along with increased road hazards.economic activities along with increased road hazards.  
> Suspended hydrocarbons cause health problems like allergy, asthma, cancer, ealth problems like allergy, asthma, cancer, cardiovascular complications.cardiovascular complications.
>> Lichen is very sensitive to air pollutants. So, lichen population is a good indicator of air quality.sensitive to air pollutants. 


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2015-01-31T15:29:39+05:30
Lichens is the good indicator of air pollution in that area

 AIR POLLUTION - harmful substances introduced in the air by the activities of mankind such as constructions .
 they are cause by both natural as well as man - made
natural sources- Volcanic gases , cosmic dusts , etc.
man made sources - increase in population , deforestation , fires , industrilization , etc.

CAUSES - the oxides of nitrogen and sulphur dissolves in rain water and gives acid rain which causes effects on living organisms
              - composition of fuels and dusts particles increase the suspended particles in atmosphere . 
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