Water-borne diseases are illnesses caused and transmitted by the use and consumption of contaminated water. Irrespective of the cause and point of water contamination, infections are picked up in the course of basic everyday activities like drinking water, preparation and consumption of food, bathing and washing.
The long list of water related diseases and conditions include Anaemia, Ascariasis, Botulism, Diarrhoea, Dracunculiasis, Fluorosis, Hookworm infection, Japanese encephalitis, Lymphatic filariasis, Malaria, Malnutrition, Polio, Ring Worm, Tinea, Scabies, Schistomiasis. But prevalently, the most common and the most troublesome of water related diseases, in terms of public health or health of a community are:
- Typhoid fever
- Hepatitis A
There is also the increased risk of infection or water-borne diseases contracted through direct contact with polluted waters. Among them are:
- Wound infections
- Ear, nose and throat infections
Transmission: Public or private drinking water systems may be contaminated with urine and faeces of people or animals. This is likely to occur where surface water is the source of public and private drinking water systems. Water collected from rain, creeks, rivers, lakes– all account for surface water. Runoff from landfills, septic fields, sewer pipes, residential or industrial developments can also sometimes contaminate surface water.
Prevention: Clean water is a pre- requisite for reducing the spread of water-borne diseases. It is well recognised that the prevalence of water-borne diseases can be greatly reduced by giving due attention to the quality of drinking water and the safe disposal of faeces.
In developed countries access to safe drinking water through piped water supply has led to a dramatic decrease in rates of infections. This is still a scarcity in developing countries.
Piped Water: In India, the concerns with piped water remain in terms of cross contamination with a sewage system in certain cases. Piped water is ideally provided as a continuous supply, which is not the case in India. Most of our urban centres have timed water supply. This leads to increased risk of contamination due to the low pressure that develops in the system. In spite of these problems the availability of piped water has significantly reduced gastrointestinal diseases.
Bottled Water: The bottled water business is not an efficiently regulated industry in our country.
Even in countries like the USA, close to 50 per cent of the bottled water is tap water that is filled into plastic bottles. The mineral content in bottled water is not regulated. The other issues with bottled water are the environmental contamination due to the increase use of plastic, which is a petroleum product. Bottled water can have physical and chemical contaminants.
Physical Contaminants: Physical contaminants can sometimes be found within bottled water even though it has been quality checked. Pieces of plastic, glass or industrial supplies may enter the water during the bottling process. If these contaminants are ingested, they can cause stomach and other health problems.
Chemical Contaminants: The WHO states that chemical contaminants, such as lead, arsenic and benzene, may be present in bottled water. If chemical contaminants build up to high levels they can cause a range of health complications. Carcinogens, or chemicals that may cause cancer, can be found in bottled water. If carcinogens are frequently consumed through bottled water, they can build up in the human body and increase the risk of cancer.
Overhead Tanks: The overhead tanks contain water in a stagnant condition. Stagnant water is an ideal environment for proliferation of bacteria. Plenty of disease causing organisms can be found including salmonella, giardia, vibrio cholera etc. The tanks have to be cleaned periodically in order to avoid these problems.