Summary

Abstract

The increases in the release of toxic agents from technical installations as well as from commercial and household uses of such agents have led to heavy pollution in some regions. In order to protect human health and the environment it is necessary to establish relevant environmental standards, which limit exposures to these toxic agents. The assessment and decision-making procedures have to be based on solid scientific data about the effects and mechanisms of these agents. For risk evaluation, the knowledge of the dose-response curve is an essential prerequisite. Dose-responses without a threshold dose are most critical in this connection. Such dose-responses are assumed for mutagenic and carcinogenic effects, which, therefore, dominate the discussion about environmental standards. In the important low-dose range, risk estimation can only be achieved by extrapolation from higher dose ranges with measurable effects. The extrapolation is accompanied with uncertainties which makes risk evaluation as well as risk communication frequently problematic. For the regulatory processes besides legal requirements and administrative procedures, ethical, social and economic aspects are important. In order to secure rational efficient and fair decisions a dialogue between disciplines, with the affected people and with the general public is necessary. The whole range of relevant aspects, starting with the ethical foundations, going to the scientific data, the contribution of theory of cognition, and concluding with the social and legal perspectives are dealt with in the report.