ABSTRACT
There are three requisites for human life: a supply of air, an adequate quantity of nutritious food, and water to drink. But while some societies are nourished mainly by rice, or meat, or fish depending on local tradition and availability, all depend on water, the global victual. To most people, however, the mention of chemicals and drinking water conjures up visions of pollution and associated subtle ill-health manifestations. "Naturally—–occurring" substances include minerals leached from the underlying geological formations, such as calcium and fluoride as well as organic substances such as humic acids contributed from soils and sediments. The source of chemical contaminants in drinking water is the distribution network. In the course of its treatment and distribution, water comes into contact with a variety of structures including storage tanks, piping and plumbing fixtures. Scientists in many countries have used mutagenicity tests as a means of screening drinking water and extracts and concentrates prepared from drinking water.
