It is a common fact that most diseases and illness in children and adults alike are caused by drinking water. Water is a biotic element which means living organisms thrive or grow in water. Hence water is an abode for microbes - bacteria, viruses and protozoa. There is also the presence of minerals and impurities in water.
Untreated or unfiltered water houses several microbes most of which may not be harmful for the human body. There are a microbes which can cause gastrointestinal diseases. A few examples of diseases caused by microbes are
Bacteria - Causes Cholera, dysentery and typhoid fever
Viruses - Cause hepatitis and stomach ailments
Protozoa - Can cause diarrhea and mild gastrointestinal diseases in adults and severe diseases in infants.
The presence of microbes in drinking water can also lead to short spells of vomiting and fever. Most adults are immune to microbe attacks, but infants and older people would have more severe consequences.
Tap water is the most common source of drinking water in most parts of the world. The most harmful chemical which can be present in such water supplies are
Chlorine - It is used to treat drinking water to kill bacteria, but it does harm your skin and hair by making it dry.
Lead - Can severely harm the kidneys, brain and nervous system
Pesticides - Can lead to chronic health problems
Benzene - It is known to be carcinogenic (cancer producing)
Mercury, Arsenic and Cadmium - the presence of these heavy metals in drinking can lead to nervous disorders.
Fluorine - Severely affects your teeth and gums
Prevention is always better than cure.