Adequate supply of pure drinking water is the requirement for healthy life. Contamination of drinking water causes health hazards and some times leads to death. There are some common types of contaminants which pollutes water are given below.
Presence of microbes such as coliform bacteria and cryptosporidium in drinking water leads to contamination of water. This causes several diseases. Coliform bacteria is not a harm causing bacteria but its presence in water affects the distribution system and there by causes diseases to humans.
Cryptosporidium is a parasite that enters water through sewage and animal wastes. It has an outer shell that makes it to survive outside the shell and there by it become tolerant to chlorine disinfectant. Drinking water contaminated with this causes cryptosporidosis, a mild gastro intestinal diseases.
Drinking water contaminated with radio nuclides may increase the risk of cancer. Radio nuclide contaminants include alpha and beta emitters and radon gas. Some minerals are radio active and emits radiation known as alpha or beta radiation. People drinking contaminated water for long increase the risk of cancer.
Chemical contaminants in drinking water leads to health diseases. Some of the naturally occurring chemical contaminants that contaminates water are arsenic, fluoride and lead.
Fluoride in low amounts is added to drinking water to prevent dental problems. High amount of fluoride in water causes dental fluorosis and much higher amounts in water leads to bone fractures.
Arsenic is a toxic heavy metal. Excess amounts of it in drinking water leads to severe health diseases. It affects lungs, kidneys, bladder and liver. It also affects central nervous system. It increases the risk of cancer.
Lead enters into the drinking water through corrode plumbing systems. It affects children and pregnant women. Drinking contaminated water delays mental and physical growth of children and impairs learning capabilities.
These include carbon tetra chloride, benzene and chlorobenzene. Benzene discharged from factories and also leaching from gas storage tanks. Water contaminated with it leads to decrease in blood platelets and anemia. Carbon tetra chloride is discharged from chemical plants and other industrial activities. It causes liver problem and increases the risk of cancer. Drinking water contaminated with chlorobenze leads to liver and kidney damage.
Disinfectants are added to the drinking water to kill microbes in the water. Excess amounts of it affects eyes, nose and stomach. These contaminants include chlorine, chloramine and chlorine dioxide.