ABSTRACT
In 1983 the National Research Council published an analysis of the process of controlling risk due to exposure to adverse agents. Four steps were described for risk assessment: recognition of hazard, toxicity testing, estimation of exposure, and decision for management of the risk. One criterion for deciding to test is recognition that exposures, especially on a large scale, are taking place or soon takes place. Both the method of testing and the reliability of the results are of concern. Toxicologists determine what levels of exposure are safe for the target population, those who are exposed, then set standards to ensure that these levels are not exceeded. In order to set realistic exposure guidelines, first consider the target population. When estimating the hazards of concurrent multiple exposures, health and safety specialists often assume additivity of the risks of the individual chemicals.
