Affects of environmental pollution

When a change occurs in physical, chemical and biological characteristics of air, land and water and this change is harmful to human and other forms of life it is called pollution. An environmental pollution is a result of natural causes such as volcanic eruptions; but most are caused by human activities.
Two main categories of pollutants are materials such as sewage, that rapidly decompose by natural processes. These pollutants become a problem when added to the environment faster than they can decompose. Non-degrable compounds such as dichlorodiphenyhtrichloroethane (DDT), dioxins and radioactive materials can reach dangerous levels of accumulation as they are passed up the food chain into the bodies of progressively larger animals.
KINDS OF POLLUTION: Pollution exists in many forms and affects different aspects of earth's environment. Point source pollution comes from specific, localised and identifiable sources such as sewage pipelines or industrial smoke stacks.
Non-point source pollution comes from dispersed or uncontained sources such as contaminated water runoff from urban areas or automobile emissions. Different kinds of pollution are present in environment. First, it is a major problem of pollution in environment.
1. AIR POLLUTION: Air is essential for life. Air contains 21% oxygen. When other gases or harmful materials are increased in air, it is called polluted air and is known as air pollution. Air pollution occurs by the addition of poisonous gases and other matters. These gases are produced by the burning of different fuels and waste materials in the automobiles, industries and domestic uses.
Air pollution affects man, animals as well as plants. Nitrogen-dioxide (NO2) is produced from industries and burning of fuels at high temperature. They have a highly oxidising effect, killing plants and animals. In cold and humid conditions, Nitrogen oxides combines with hydrocarbons and forms smog. It is the combination of smoke and fog. Smog causes irritation and burning of respiratory tract, lungs and eyes. Urban air pollution is commonly known as smog. Smog developed into a major health hazard by 20th century.
Sulphur dioxide (SO2) is produced by burning of sulphur containing coal. It affects the lungs temporarily or permanently. It causes lung cancer and heart disturbances. (SO2) also causes severe reduction in the growth of plants. Carbon mono-oxide (CO) is produced by incomplete burning of carbon in petrol. It is poisonous gas due to which red blood corpuscles (RBCs) cannot get oxygen properly. It causes diseases and is very harmful to heart, respiratory and anaemia patients.
They cause ulcer and damage lungs and other tissues of the body. The particulate matter arises from various industries, consists of chemicals, pesticides and poisonous substances which cause tuberculosis and other diseases. Rocket fuels smoke causes damage to respiratory tract, produces wounds on lungs and some times death may occur.
OTHER WAYS OF AIR POLLUTION: Other ways of air pollution are acid rain, green house effects and depletion of Ozone layer.
2. WATER POLLUTION: When physico chemical and biological properties of water are affected by the addition of organic and inorganic substances and it becomes unfit for a particular use, it is called water pollution.
Water pollution is caused by the discharge of excretory substances from industries, municipal areas and agricultural lands. These substances contain poisonous matters and they reduce the oxygen content of the water body on which most of the aquatic life depends. Soil erosion (Leaching and washing from the soil) oil flow, drainage of mines and waste material from fishing ships are also responsible for water pollution.
It is estimated that there is a continuous increase of population every year and so the demand of water would also be increased accordingly. The US Environmental Protection Agency (EPA) reports that about 37% of country's lake and estuaries, and 36% of its rivers, are too polluted for basic uses such as fishing or swimming during all or part of the year. In developing nation, more than 95% of urban sewage is discharged untreated into rivers and bays, creating a major human health hazard.
3) LAND POLLUTION: The land pollution occurs by the solid wastes and chemicals. These materials include agricultural wastes, such as farm and animal manure, crop residues, industrial waste, paper, card board, rubber, plastic, clothes, leather and chemicals, house hold materials like metals, glass, tins, cartons, sewage wastes, construction materials such as bricks, sand and some times old refrigerators, washing machines, autos and body of dead animals are also deposited in land. All these materials cause land pollution. These waste products contain harmful substances which cause illness and sometimes may cause death.
Soil erosion also increases land pollution. Due to heavy rain and stormy wind the superficial layer of soil is removed. This layer actually contains many nutrients, which are necessary for plant growth and development. Such soil becomes Infertile. It takes a long time to restore it into its original form and shape Careless farming methods and grazing also cause land pollution. By these methods plant cover is destroyed and soil is exposed for erosion.
4). NON MATERIAL POLLUTION: Non material pollution also affect environment and are of different types. These are Radiation Pollution, Noise Pollution and thermal pollution.
CONTROLLING POLLUTION: Because of many environmental tragedies of the mid 20th century, many nations instituted comprehensive regulations designed to repair the past damage of un controlled pollution and prevent future environmental contamination.
In United States, the Clean Air Act (1970) and its amendments reduced certain types of air pollution. The Clean Water Act (1977) and Safe Drinking Water Act (1974) regulated pollution discharges and set water quality standards. The Toxic substances Control Act (1976) and the Resource Conservation and Recovery Act (1976) provided for the testing and control of toxic and hazardous wastes.