Acid rain:

•     pH of normal rain is 5.6

•     pH of rainfall in north eastern areas of North America is 3.9 to 4.3.

•     It is 10 to 100 times more acidic than normal. This is ‘acid rain’.

•     Snowmelt into water releases huge amount of acid which got frozen during winter.

Effects:

• ‘Acid shock’ from snowmelt causes mass destruction of fish. On long term it also harms fish eggs and sources of food.

•  Thousands of lakes were killed by acid rain in Scandinavia and North America.

• The causes are burning of fossil fuels leading to release of SO2 in particular and Nitrogen oxides.

•  Problems of Sweden caused by Industrial plants in England and North Europe.

•  Problems of North America caused by utilities in Ohio valley, the largest polluter of SO2

in USA.

•  Some of the potential changes are still unknown

     Micro organisms in soil are being affected

     Groundwater is polluted but its ultimate effects are not known

     The effects may be known only after another 100 years

•  Effect on food sources are also unclear