This course will deal with human health hazards related to chemical exposures in the workplace and environment. Topics covered include basic principles governing toxic responses, i.e., dose/response relationships, approaches to toxicity testing and risk assessment, the effect of biological systems on a chemical substance (absorption, distribution, biotransformation and excretion) and the effects of chemicals on biological systems (reaction with critical target molecules, initiation of key events that may lead to toxicities and pathologies). Cellular and molecular mechanisms of such toxic effects will be discussed, as well as environmental, physiological and chemical modulators of toxic responses. The impact of industrial chemicals on various organ systems, their role in the aetiology of various diseases, the toxicities associated with classes of chemicals, as well as assessment of risk to individuals exposed to toxic substances will becovered.