Causes
Combustion
of fossil fuels (in power stations, domestic & industrial boilers)
Releases
sulphur dioxide & oxides of nitrogen (NO & NO2)
Both
the gases combine with water vapour formed sulphuric acid & nitric acid
They
fall to earth as acid rain (with pH less than 5)
Effects
The soil becomes very acidic
Thus, unsuitable for cultivation of crops
Causes leaching of minerals (such as potassium, calcium, magnesium)
Affects growth of crops
Photosynthetic tissues are destroyed.
Reduce the producers.
Germination of seed & growth of young seedling is inhibited.
Insoluble aluminium ions accumulate in lakes & rivers (due to leaching)
This can kill aquatic organisms (excessive secretion of mucus by fish gills)
Kill phytoplanktons (that affects the food chain)
Acidic soil releases ions of certain heavy metals (Eg. mercury, lead, cadmium)
This can contaminate supply of drinking water.
Metal railings, steel, cars, bridges, underground pipes corrode
Corrosion of sandstone & limestone.
Ways to overcome
Use scrubbers that clean up emissions from power stations & industrial plants
Use catalytic converters that clean up emissions from vehicle exhaust
Effects
The soil becomes very acidic
Thus, unsuitable for cultivation of crops
Causes leaching of minerals (such as potassium, calcium, magnesium)
Affects growth of crops
Photosynthetic tissues are destroyed.
Reduce the producers.
Germination of seed & growth of young seedling is inhibited.
Insoluble aluminium ions accumulate in lakes & rivers (due to leaching)
This can kill aquatic organisms (excessive secretion of mucus by fish gills)
Kill phytoplanktons (that affects the food chain)
Acidic soil releases ions of certain heavy metals (Eg. mercury, lead, cadmium)
This can contaminate supply of drinking water.
Metal railings, steel, cars, bridges, underground pipes corrode
Corrosion of sandstone & limestone.
Ways to overcome
Use scrubbers that clean up emissions from power stations & industrial plants
Use catalytic converters that clean up emissions from vehicle exhaust
Causes
Increase level of CFCs (chlorofluorocarbons
CFCs used in coolants in air conditioners / refrigerators // propellants is aerosol cans // foaming agents making styrofoam / polystyrene
Increase level of CFCs (chlorofluorocarbons
CFCs used in coolants in air conditioners / refrigerators // propellants is aerosol cans // foaming agents making styrofoam / polystyrene
(Once
in the atmosphere) CFCs are broken down by UV rays into chlorine radicalsChlorine
radicals break down ozone molecules (O3)
Effects
Ozone
depletion causes direct exposure to UV radiation.
Prolong
exposure causes skin cancer, cataracts & sunburns
UV rays also weaken immune system / decreases body resistant against infectious disease
UV rays reduces nutrient contents & crop yields
UV rays also weaken immune system / decreases body resistant against infectious disease
UV rays reduces nutrient contents & crop yields
Leaf
cells & chlorophyll are easily damaged
UV
rays also kill microbes & phytoplankton
Leads
to increase in the earth temperature / global warming
Ways
to overcome
Reduce
/ Stop uses of CFCs
Replace
CFCs with HCFCs or HFCs.
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