Implications for human health.

To analyze the implications for human health, the toxicologist requires four sets of data: the results of toxicity and other studies in animals; quantitative data on actual or potential human exposure; whatever information is available on effects of exposure in man; and the statistical extrapolations from the dose-response relationships in animals to the (usually) much lower levels of human exposure. Professional expertise in toxicology is essential to assess the nature and severity of the toxic effects observed in animals, including such characteristics as potential for progression, irreversibility and production of incapacity. Given sufficient data, an estimate can be arrived at of the likelihood that such effects will be elicited in human populations of differing susceptibilities. The criteria by which the overall implications for human health can be judged comprise both the direct effects on man, as well as the indirect consequences stemming from environmental impacts.