What is Acid Rain?
A rain in which the precipitation is unusually acidic is called an acid rain. It contains high levels of hydrogen ions. Acid rain is caused when sulphur dioxide and nitrogen dioxide emissions react with water molecules in the air and result in producing acids. These chemicals are produced because of natural sources like decay of vegetation, volcanoes and also from manmade sources like emissions from factories and various types of pollution in the atmosphere. When these gases react with water that is present in the air, form into various acidic compositions.
Acid rains are very harmful to the atmosphere. Steel structures like bridges and towers corrode because of the acid. It also results in the peeling of paint from the painted surfaces like buildings. Stone structures get eroded because of the acid in the rain.
The acid deposition can be in two forms, wet and dry.
Wet deposition is in the form of acid rain, snow and fog. The chemicals that are present in the air are blown to areas that are wet and fall to the ground in the form of rain or fog. This acid in the rain affects plants and animals.
If the weather is dry, the chemicals present in the atmosphere get merged with the dust and smoke and get stuck to the ground, trees, vehicles and buildings. When rain falls to the ground these chemicals get washed from the surfaces and get mixed into the rain water. Almost half of the acidity in the air gets back to the earth in the form of dry deposition.
What are the effects of acid rain
Acid rain shows adverse effects on human health, forests, sources of fresh water like rivers and streams, and on soil affecting different life forms surviving in these mediums.
On aquatic animals
Acid rain contains low pH level and high aluminum levels which causes tremendous impact on the life forms in water and on the surface. At lower pH levels fish eggs cannot hatch and it also results in killing of the fish. Because of acid rain fresh water sources like rivers and streams also become acidic in nature. In many water resources several aquatic life forms got eliminated because of the acid.
The chemical and biological compositions in the soil get seriously disturbed by acid rain. Microbes which cannot tolerate low pH levels get killed. Microbe equilibrium in the soil gets damaged. When calcium and magnesium levels get leached by the acid rain sensitive species get affected.
On forests and vegetation
Forests which are situated in high altitudes get adversely affected as these are close to the clouds and fog that are acidic in nature. Plant life is the worst affected Calcium deposits get leached because of acid rain and as a result trees lose their tolerance for cold and become seriously affected or many times they are left dead. Growth is stunted in tress, the trees lose leaves and they become more vulnerable to diseases.
But the soil in which food crops are grown is checked for pH balance and with the use of lime and other fertilizers, the loss is minimized.
Forests all over the world get affected by acid rain but majority of the damage is seen in Eastern Europe. In countries like Switzerland, 30% of forests are effected whereas in countries like Poland and Germany 50% of forests are destroyed because of acid rain.
Human health is not directly influenced by the acid rain. The chemicals that become responsible for the acid rain are harmful to human health. The presence of chemicals in the air will show the impact on lungs and heart. It may lead to diseases like bronchitis and asthma.
Acidity in the air can cause damage to manmade structures like bridges, railway tracks and buildings. The impact is seen on aircrafts as well.
Several governments all over the globe are planning measures to curb acid rains. The circumstances responsible for the formation of acids in the air should be thoroughly checked and precautions should be taken not to pollute the atmosphere. Especially vehicle emissions are one of the biggest problems that result in acid rains. Alternative energy sources should be encouraged and burning of fossils should be minimized.
Man is responsible for the advancement and degeneration of human society with his latest innovations and discoveries. Many times it has become difficult to overcome the adverse effects of technology on nature. Science has to continuously innovate and look for ways to overcome the problems created by man himself.