Chemicals in the water environment. Where do the real and future threats lie?

There are many potential sources of chemical constituents and contaminants in water that can reach drinking water. Not all substances will be present in any particular water. Some substances may be of benefit to health but others can be a threat. However, very few have been clearly shown to cause adverse health effects in humans through drinking water and evidence may be complicated by simultaneous exposure through food. Our knowledge of contaminants in water is, however, incomplete as additional contaminants emerge with advancing analytical methods. Most of these emerging contaminants are present as a consequence of day to day use by the wider human population and control requires a different approach to the substance by substance regulation prevalent at present.