What do cholera, dysentery, Hepatitis A, Hepatitis E, typhoid, gastroenteritis, malaria and giardiasis have in common? Okay, I know, all of them are diseases - but there is something else common among them other than this fact. All of these are primarily waterborne diseases. Waterborne illnesses and infections are caused when various micro organisms or chemical pollutants contaminate water which is, then used for the purpose of consumption of preparing edible items such as food and beverages. Speaking about the types of waterborne diseases, all infections and diseases that are caused by contaminated water can be broadly classified into two categories - those caused by micro organisms and those caused by chemical pollutants. Let's take a brief, to-the-point look at a more detailed classification of the various categories of waterborne infections and diseases. Different Kinds of Waterborne Diseases As mentioned above, waterborne diseases can be classified under two broad categories - chemicals induced and microbes induced. Chemical induced diseases such as cancers and various radiation related illnesses are caused by chemical pollutants present in water. These pollutants find their way to water resources as a result of malpractices such as dumping industrial wastes in rivers and the ocean, oil and chemical spills, etc. Microbes induced diseases such as various stomach and digestive disorders, typhoid and other pathogenic infections are caused by harmful bacteria, viruses or waterborne parasites and protozoans. That being said, let's take a brief look at each type of waterborne pathogen and infectant. Chemical Water Contamination and Resulting Diseases Too much arsenic in drinking water can lead to condition known as arsenicosis which takes over the body gradually. Also, pollutant chemicals such as ammonia, detergents, industrial chemical waste, petroleum spills, chemical fertilizers, etc. also lead to adverse health effects such as various types of cancers, skin diseases and various toxic syndromes on consumption of such chemically contaminated water. Usually, no immediate effect or symptom is usually evident and by the time the effects are seen, the poisoning assumes serious proportions. Other common chemical water contaminants include chloroform, food processing waste, insecticides and chemical pesticides, industrial and chlorinated solvents, etc. Pathogenic Water Contamination and Resultant Diseases Waterborne pathogenic organisms and related diseases can be further broken up into four distinct subcategories - bacterial, viral, parasitic and protozoal. Let's take a quick look at each sub category.

• Bacterial Infections: The most common waterborne bacterial diseases are typhoid fever, dysentery, salmonellosis, swimmer's ear (Otitis Externa), E.Coli infection, botulism, cholera, campylobacteriosis, Legionnaire's disease, Pontiac fever, leptospirosis, Vibrio illness, etc. While most of these are caused by drinking contaminated water, some diseases such as swimmer's ear, botulism and Vibrio illness can be contacted when the pathogenic bacteria enters the host through any broken skin or topical wound.
• Viral Infections: Some of the most common viral infections contacted from water contaminated with pathogenic viruses include Hepatitis A, acute gastroenteritis, Severe Acute Respiratory Syndrome (SARS), Hepatitis E, polio, Polyomavirus infection (causes problems of the kidneys, brain and respiratory organs), viral pneumonia, common cold, bronchitis and croup (all the latter 4 diseases are caused by the adenovirus).
• Parasitic Infections: Parasitic infections that can be transmitted on consuming or coming in contact with contaminated water include snail fever (bilharziosis), Taeniasis or tapeworm infection, Guniea worm disease (Dracunculiasis), roundworm infection (Ascariasis), intestinal fluke (Fasciolopsiasis), dwarf tapeworm infection (Hymenolepiasis), river blindness, enterobiasis, coenurosis, Hydatid disease, etc.
• Protozoal Diseases: Hand-to-mouth disease or amoebic dysentery (Amoebiasis), giardiasis, cyclosporiasis and cryptosporidiosis are the most common portozoal diseases that are contacted from contaminated water. Another disease, Microsporidiosis, is not that common and rarely affects individuals with a strong immune system. It mostly infects immunocompromised individuals by way of an opportunistic infection.

While most waterborne diseases are not fatal and prompt treatment can completely restore the patient's health as it was previous to contacting the infection, some of these diseases such as typhoid fever, polio, SARS, etc. can assume serious conditions and can even become fatal if proper medical attention is not solicited in the initial stages itself. Keeping this in mind, it is best to strive for prevention of such diseases by making sure that the water that is meant for consumption is adequately sanitized and treated to keep it free from microbial pathogens. For this purpose, water purifying units that kill all micro organisms in water should be installed. In absence of such units, drinking water should be boiled and stored in clean, sterilized vessels. Also, for preventing chemical contamination, proper industrial waste management and waste treatment should be resorted to instead of irresponsibly dumping all the industrial garbage into rivers. Also, the use of chemical fertilizers and pesticide should be stopped and organic agricultural methods should be promoted as they keep both water and soil clean.