Water is the most important element for survival of human beings. At the same time it is also a valuable resource for agriculture and industries. With worldwide industrial growth, economic development, rapid population growth, and urbanization, pollution in drinking water has become a worrying concern for human health. Pollutants such as human feces, industrial chemicals and toxic agents are often discharged and dumped untreated into fresh water lakes and rivers. This may have an enormous health consequence on health of human beings. Contaminated drinking water contains various impurities that are biological, physical and chemical in nature.
Water borne disease occurs by drinking polluted water.
The major reasons of water pollution are:
- Domestic sewage
- Pesticides and fertilizers
- Littering of plastic and polythene bags, aluminum, heavy metals etc in rivers, oceans, lakes and other water bodies.
- Population growth
- Improper management facility of drinking water
- Rapid urbanization and industrialization.
Diseases caused due to water pollution:
- Bacteria, viruses, and protozoa can contaminate water and spread diseases such as typhoid, cholera, dysentery and diarrhea, jaundice, amoebiasis, dengue, filariasis, malaria etc.
- Metals such as lead, arsenic, mercury, copper, from industrial waste water can have adverse effect on health of humans. They may accumulate in the body causing damage to central nervous system, bones, and skin.
- Water polluted with arsenic can get accumulated in the body parts such as nails, hair, skin leading to various symptoms such as dry and thickened skin. It is one of the causes for skin cancer.
- Mercury mixed in water from industrial waste may be converted into methyl mercury by the bacteria present in water. If the contaminated water is consumed by a person it can lead to numbness in tongue and extremities. It also damages hearing ability and vision. It can also lead to mental retardation in the child if mother is exposed to it during pregnancy.
- Lead pollution can cause anemia, weakness in muscles, headache, blue discoloration on gum.
- Water contaminated with radioactive substance causes cancer of lungs, liver, bone etc.
- Fluoride present in excess in water can cause yellow discoloration of teeth and damage to the spinal cord.
- Benzene and other petrochemicals polluting water which if consumed can cause cancer etc.
- Nitrogenous chemicals polluting water can cause cancer and blue baby syndrome.
Disease rate from water pollution is higher in rural area than in urban inhabitants. This is because in urban areas usually drinking water is treated and purified before it reaches every household. This may not be the case in rural areas. Often people in rural areas drink water that is not processed. People living in poverty are at greater risk of suffering from waterborne diseases because of poor sanitation, hygiene and water supply.