ABSTRACT
Food and drinking water are major sources of human exposure to a large number of chemicals added intentionally for technological reasons or present unintentionally due to contamination. The concern over the presence of chemicals in the human diet received further emphasis through the development of toxicological and analytical methodology with increased sensitivity. The presence of chemicals in drinking water is often a consequence of ground water contamination. Toxicological evaluation encompasses both hazard identification and dose-response assessment. Assessment of exposure is of great value, as a compound might be extremely hazardous but pose little risk if the exposure to it is low. Human data, especially those from controlled human exposure studies, are valuable in several ways. The practice of risk assessment depends largely on the type of toxicological endpoint observed. Safety assessment of chemicals showing non-threshold toxic effects, mainly genotoxic carcinogens, is less straightforward.
