[Progress report. Factors influencing nutritional toxic effects]

The basis of the requirement for nutrio-toxicological model investigations is the result of many years of international experience. They are, however, limited for pragmatic reasons to standardized one-dimensional test conditions and can only be partially compared with the variable exposure conditions of man. Therefore, we have tried to review the practical significance of factors influencing nutrio-toxic effects. It has been shown that due to physiological and genetic differences, different lifestyle, biogeochemical and nutritional factors, additional occupational exposure as well as spontaneous diseases individual sensitivity shows a great variation range in man and laboratory animals. The multiple exposure which is common practice makes it difficult to provide proven evidence. The safety factor used for the extrapolation of results obtained in animal experiments as compared with man is a suitable pragmatic safety measure, but in the case of 1:100 as to the order of magnitude it is not always in accordance with the range of response to xenobiotics in a human population. This fact raises the necessity of searching for so-called "risk-groups" in the population. Additionally, the possible acceleration of spontaneous diseases by exposure to xenobiotics has to be taken into consideration.