Home arrow Knowledgebase arrow Acid rain & it leads to corrosion of buildings
Acid rain & it leads to corrosion of buildings

Acid rain
Acid rain is caused by emissions of sulphur dioxide and nitrogen oxides.

Although natural sources of sulphur oxides and nitrogen oxides do exist, more than 90% of the sulphur and 95% of the nitrogen emissions occurring in eastern North America are of human origin. These primary air pollutants arise from the use of coal in the production of electricity, from base-metal smelting, and from fuel combustion in vehicles. Once released into the atmosphere, they can be converted chemically into nitric acid and sulfuric acid, both of which dissolve easily in water. The resulting acidic water droplets can be carried long distances by prevailing winds, returning to Earth as acid rain, snow, or fog.

Acid rain is not always wet. Acid can be transformed chemically into sulphur dioxide gas or into sulphur and nitrogen salts. In this form they are deposited 'dry', causing the same damage as when they land dissolved in rain or snow.

If rain is naturally acidic, the problem is one of balance; nature depends upon balance. Normal precipitation reacts with alkaline chemicals that derived from the region's bedrock and found in the air, soils, lakes, and streams; and is thereby neutralized. If precipitation is more highly acidic, then acid-buffering chemicals can eventually become depleted. In this case, the buffering effect will no longer occur and nature's ability to maintain balance will have been destroyed.

If buffering effect is disrupted, and when the environment cannot neutralize acid rain, then damage occurs to forests, crops, lakes, and fish. Toxic metals such as copper and lead can also be leached from water pipes into drinking water.

Acid rain leads to corrosion of buildings
Acid rain leads to corrosion of buildings. The acids corrode metals, paints and concrete.

The damages are most severe where the ground consists of hard rock species with low contents of calcium and which weather slowly, such as granite and gneiss. Acid rain has had catastrophic consequences on fresh water fish stocks in Agder, Telemark and Rogaland counties.