The phenomenon of Acid Rain was first discovered in 1952 by Robert Angus Smith at Manchester. The precipitation mainly of oxides of sulphur and nitrogen with rain is termed as acid rain. PH value of such kind of rain is below 7. Today, the problem of acid rain is one of the major environmental issues which world is facing in general and India is in particular.
This phenomenon is fast becoming grave global ecological problem, threatening forests, farms, human health and aquatic life. During recent decades, the anthropogenic addition of oxides of sulphur and nitrogen into the atmosphere has resulted in further lowering of PH of rain water as often low as 2.4
This acid rain has several harmful effects. Such as:
(i) Mineral balance is disturbed:
ADVERTISEMENTS:
Due to effects of acid rain, the mineral balance in forests, rivers fields and lakes are being disturbed.
(ii) Heavy decrease in productivity:
There is heavy decrease in the productivity of crops, forests and aquatic life. Acid rain also kills nutrient algae, fungai and many useful bacteria which are so essential for the fertility of the soil. This ultimately results in decrease of productivity.
(iii) Decreasing resistance power of life in terrestrial and aquatic system:
ADVERTISEMENTS:
Acidity also kills fish, bacteria and algae and aquatic ecosystem collapses, leaving a crystal- clear dead lake
(vi) Decay of physical elements: Acid rain attacks building materials principally sandstone, marble, steel, nickel etc. which is called as stone cancer,
(v) Micro:
Organisms are also gradually becoming inactive. For eg- Azotobacter’s efficiency is reduced under acid precipitation.