All nature is full of water, but not all water is potable (fit for consumption). Only 0.3% of the total water available to human is considered as "drinking water”. For a water to be potable, it must have a quantity of substances that you can safely consume everyday without any risk of health problems. Even clear water can contain all kinds of substances harmful to your body. These substances may come into contact with the water either during its journey in the river, discharges of certain human activities, or particles suspended in air (organic or chemical). To be portable, the water you use at home must be filtered.

Nowadays, it exists several methods of water treatment. Some of them include filtration, water is passed through a filter that intercepts all small particles; disinfection, the use of ozone to eliminate micro-organisms, bacteria, viruses and protists in the water; reverse osmosis, high mechanical pressure applied to force the water to pass through a semi-permeable membrane to retain all harmful substances. However, this article is mainly centered on the effects of untreated water on your health.

Some micro-organisms and bacteria in the water (untreated water) can lead to very serious health problems. For example, E. coli is responsible for colibacillosis, the vibrio cholerae (also Kommabacillus) can lead to cholera; and some amoebae, real parasites of the human body, can trigger severe diarrhea. These medical conditions are not life threatening if action is taken immediately. In case of negligence or lack of appropriate care, these illnesses can lead to significant dehydration or death. Water contamination can also cause fever, gastrointestinal disorders and kidney problems.

Untreated water may contain heavy metals. Although their content in water is very low, once inside your body, these heavy metals are not eliminated by the body; they accumulate. Their prolonged ingestion may be harmful to your health, causing serious illness.

Lead, one of these metals, tends to disrupt the nervous system and the reproductive system. Studies have demonstrated that children exposed to low doses of lead for prolonged periods can develop Saturnism, a form of lead poisoning causing anemia, encephalopathy, gastrointestinal and nervous system problems. Chronic lead poisoning in adults can lead to reproductive disorders, kidney failure, encephalopathy, or miscarriage in pregnant women.