Emissions from industrial operations like smelting and refining cause the release of sulphur dioxide and nitrogen oxide into air. Burning of fossil fuels like coal and oil also cause emission of harmful gases. These gases combine with water vapor in the clouds to form sulphuric and nitric acids. So the precipitation that falls on the ground is highly acidic, having a pH value of about 5.6 or even lower. A pH scale is used to indicate levels of acidity. The scale ranges from 0 to 14 and lower numbers indicate high acidity. In fact, pH values as low as two and three have been recorded in several areas of eastern US and Western Europe.

What it does?
Acid rain stops the growth of plants and defoliates them before time. Evidence of the damage caused by acid rain has been found in Germany’s Black Forest, where almost half of the trees have been damaged by acid rain. Vegetation in the north-eastern US and eastern Canada have been similarly affected. In the USA, in 1981, it was found that almost all fish had disappeared from a lake near New York due to acid water. This is mainly

Formation of Acid Rain

because acid rain upsets the balance of rainwater. Structures like the Taj Mahal and many other famous statues like the Statue of Liberty have showed the negative effects of acid rain. Acid rain makes the stone weak and reduces the lifespan of these structures.