How Acid Rain is affecting our ecosystem and how to prevent it?

Acid rain is defined as the precipitation or rain that is usually acidic. It has PH value less than that of natural rainwater (which is around 5.6 due to dissolved carbon dioxide). In the atmosphere, sulphur dioxide and nitrogen oxide combine with water vapour and precipitate as sulphuric acid or nitric acid in rain, fog or snow. Acid rain is usually measured using pH scale. The lower a substance’s pH, the higher acidic it will be.

There are both natural and human causes of acid rain. The natural causes include emissions from volcanoes and from biological processes which occur on land, wetlands and in oceans. There are also effects of acidic deposits which have been detected in glacial ice thousands of year old in remote parts of the world.

The main cause of acid rain is from human sources. These sources include industrial factories, power generating plants and vehicles. During combustion, sulphur dioxide and oxides of nitrogen are released which are main causes of acid rain.

During rainfall or when water vapour condenses, they dissolve in the water to form sulphuric acid (H2SO4) and nitric acid (HNO3). In this way air is cleaned of the pollutants, but it also causes precipitation to become acidic.

Acid rain can be in the form of wet deposition as well as dry deposition. In wet deposition, acid chemicals are blown into areas where weather is wet. The acid falls to the ground in the form of rain, fog, snow and mist. It affects wide variety of plants and animals as the water flows through the ground. In dry weather regions, the acid is incorporated into dust or smoke and then falls to the ground through dry deposition. It sticks to the ground, buildings, homes, cars and even trees.

Acid rain has badly affected some countries. Acid rain is main problem in Canada. Water and soil system don’t have natural alkalinity such as lime base, thus acid can’t be neutralized. Canada has vulnerable hard rocks such as granite which don’t have capability to neutralize effectively acid rain.

Industrial acid rain is also problem in China, Eastern Europe and Russia. In United States, acid rain from power plants has badly harmed the forests of upstate New York and New England. It means that effects of acid rain can spread over large area, far from source of the pollution.

There are many harmful effects of acid rain on humans, animals, plants and infrastructure. Some of them are summarized below:

1. Acid rain is harmful for human health. It creates respiratory problems like dry cough, asthma, headache and throat irritation. The toxins from the soil can be absorbed by animals and plants, which indirectly affects humans severely. Severe exposure of acid rain may lead to brain damage, kidney problems and Alzheimer’s disease.

2. It is harmful for aquatic life. It increases acidity in water bodies which stops hatching of eggs of certain organisms and thus aquatic ecosystem is affected.

3. It is also harmful to vegetation. Increased acidity in soil can leach nutrients from soil which slows plant growth. It produces brown spots in leaves of trees which hinders photosynthesis process.

4. It accelerates the weathering process in stone structures and metals. i.e. Parthenon in Athens; Taj Mahal in India are affected by weathering process.