structural:summarization, structural:scholar_edition
Purification of water

Water is the chief constituent in all drinks, and the primary ingredient in most. Water is purified prior to drinking. Methods for purification include filtration and the addition of chemicals, such as chlorination. The importance of purified water is highlighted by the World Health Organization, who point out 94% of deaths from diarrhea – the third biggest cause of infectious death worldwide at 1.8 million annually – could be prevented by improving the quality of the victim's environment, particularly safe water.