Principles in toxicological risk analysis.

Toxicological risk analysis comprises a process of hazard identification, dose-response assessment and exposure assessment, providing as an output the estimation of the incidence and severity of adverse effects likely to occur in a human population in relation to actual or eventual exposure to hazardous compounds. Within this respect, toxicological risk analysis represents a scientific activity, which uses data from toxicological research, and serves as a basis for risk management which is the decision-making process which is performed by regulators and politicians, considering also non-scientific aspects such as socioeconomic and political factors. The predominant step in hazard identification is the answer to the question whether a compound must be classified as a genotoxic carcinogen, epigenetic carcinogen or non-carcinogen. Additional important aspects concern the questions how to extrapolate from high to low dose, as well as how to deal with exposures to complex mixtures of carcinogens. Also, the question is addressed whether it is required in toxicological risk analysis to consider susceptible subgroups in the population, for instance on the basis of specific genetic predispositions.