Molecular approaches in toxicology: change in perspective.

Molecular approaches have attained a central position in modern experimental and human toxicology by providing the means to study basic underlying mechanisms. Molecular methods can be used to identify causal associations that would otherwise be obscure and to make better quantitative estimates of those associations at relevant levels of exposure. They may also make it possible to identify susceptible groups or individuals who are at risk of suffering the toxic effects of certain types of environmental and occupational agents. The use of transgenic animals in toxicology will improve our understanding of the role of toxic chemicals, such as carcinogens and mutagens, and their dosimetry and target organs. The use of molecular approaches in toxicology should thus result in better estimates of risks to human health.