Acid Rain: When the particles of Nitric acid, Sulphuric acid and such like other acids, afloat in the air, mix up with the rain water and drop down on earth, such a shower is called Acid rain.
Particles of sulphur and nitrogen oxide come along with the gas and smoke emanated from the auto-vehicles and workshops and mills are collected in the air.
The more the air pollution increases, the more these injurious chemical particles increase in the air simultaneously increasing the threat of Acid rain.
Causes of Acid rain?
Acid rain is created by the action of gases released in to the air from factories and cities. Burns of fossil fuels increases the chemistry in the air, and form stronger acids. These gases form, strong acids in the water vapor in clouds, and fall as acid rain on forests and lakes.
How does it occurs?
Generally, the oxygen and the dust particles in the atmosphere react photo-chemically with the water-droplets floating in the air and produce sulphur dioxide. This besides, the fossil-fuel combustion, mixing of air with the sulphur-dioxide released from the metal-extraction ovens and preparations of Sulphuric acid and Nitric acid through photo-chemical reaction of Nitrogen oxide coming out from the auto vehicles.
Why it is harmful?
Acid rain tends to deter agriculture on one hand and it widely harms the forests, fisheries etc. on the other hand. This kills trees in forests and makes fresh water too much acid for fish and water habitats to live in. It also damages the stone house of building.
These, by retracting with the water droplets floating in the air create dew and frost and rain-drops which come down on earth in the shape of acid rain.
Acid Rain's effect&impacts
: It is difficult to have a quantitative effect of acid rain on ecosystem. However, intense sulphur dioxide pollution around smelters is known to cause death of many kinds of trees and other vegetation.
Damages soil: Acid rain leach out soil nutrients, adversely affects the properties of soil, causes damage to soil fertility, damages vegetation including cropland and forests, makes the leaves of plants yellow and brown. This is how acid rain impacts the productivity of forests, grasslands and crops.
Damage to aquatic ecosystems: Acidification can be natural as well as anthropogenic. It kills plankton, fish and adversely affects productivity of aquatic ecosystems.
On human health: Humans are vulnerable to acid rain. Thousands of premature deaths are caused by sulphate laden air due to acid rain annually. Millions of people are drinking water with high lead levels. Lead (Pb) is one of the factors responsible for high blood-pressure and heart attacks in adults and brain damage in children. Harmful effects of acid rain on human are Chronic bronchitis, pulmonary emphysema, (related to lungs) cancer.
Acidity in soil and water due to acid rain leads to increase in dissolved metals especially aluminium. Aluminium affects the grills of fish. On account of respiratory failure they die due to heavy metals as Al (Aluminium), Zn (Zinc), Mn (Manganese), Cd (Cadmium), Pb (Lead), Cu (Copper) added in water increases acidity beyond permissible limits.
Acid Rain's typical impacts:
1. Yellowing and browning of needles and leaves.
2. Decreased annual increment.
3. Death of herbaceous vegetation.
4. Active shedding of needles and leaves while still green.
5. Death and diseased trees.
Effect on Wildlife: The impact of Acid Rain is also seen in wildlife. Acid rain carry metals bound in soil and sediment released into the aquatic environment. The toxic substances so discharged are ingested by wildlife,. This is a direct effect of acid rain. The indirect effects of acid rain are loss of food and habitat resources. The elimination of fish from lake during the breeding season is one example. Fish population has decreased tremendously. The fish-less area (lakes) are now fish grave-yards. Many bacteria and blue algae are killed due to acidification, thus disrupting ecological balance.
Effects on wildlife: Proliferation of microbial species governed by pH value. There are three pH value of water: acidic, neutral and alkaline. Many bacteria and protozoa have pH optima near neutrality; most fungi prefer an acid environment and many blue-green bacteria prefer an alkaline environment. So pH determines whether any microbial species can proliferate in a particular environment and the rate at which it can reproduce.
Solution of acid rain
It is difficult to counter the effects of acid rain on fish and wildlife without fully eliminating the sources of pollution. Certain local measures can be adopted to counter acidification of streams, soil and rest of the environment.
The measures described below acts as a solution to the Acid Rain problems:
Buffering: Methods used having deadening impact is the meaning of buffering. This is done by adding neutralizing agent to the acidified water to increase the pH value. Practice show use of lime in the form of calcium oxide and calcium carbonate.
Hatchery fish in acidified waters: This is done to maintain an ecological balance within acidified lakes. The procedure of breeding hatchery fish in acidified water curb fish population from further declining.
Controlling excess emission of SOx and NOx: Strict laws should be designed and effectively implemented by the government to regulate the emission. Some measures are:
Ordering power stations manager to burn less fossil fuels as it will decrease emission of SOx. They should be asked to use alternative sources of energy such as tidal waves, wind and hydro-power.
