14.1 Waterborne diseases
Diarrhoea, infectious hepatitis, typhoid and paratyphoid enteric fever are all examples of waterborne diseases that are common problems in our country. These are all caused by microbial contamination. Lead poisoning and fluorosis, caused by chemical contamination, are also classified as waterborne diseases.
What distinguishes waterborne diseases from other types of disease associated with water?
Waterborne diseases are caused by consumption of water that has been contaminated by human or animal wastes, or chemicals. Other types of disease may be caused by external contact (water-based), or infection by an insect vector (water-related), or by limited availability of water for washing (water-washed).
Waterborne diseases can also be classified in a different way as either acute (short-lived) or chronic (long-lasting). Acute health effects occur when the levels of some contaminants in drinking water are high enough to cause acute (immediate) health effects within hours or days of consumption, for example, vomiting. Chronic health effects occur after long-term exposure to a contaminant that may be present only in small amounts. Examples of chronic health effects are liver and kidney damage.