Among the main tasks of environmental medicine within the framework of the German Public Health Service are the assessment and management of risks involved in environmental problems. The article points out that both tasks involve ethical judgments in crucial matters. An important part of risk management is to establish limit and guiding values. The examples of drinking water regulations and WHO Air Quality Guidelines show that these values depend mainly on decisions on standard settings. It is pointed out that these cannot be derived from knowledge gained from research in natural science and that our present heterogeneous civilization is not conductive to a generally recognised basis for an evaluation. It is suggested to solve this dilemma by a process of mutual agreement on a reciprocal basis. The models of "proxy consent" and "presumed intent" are discussed. Public Health Service must therefore systematically reflect, expose and develop the standard settings of its judgments and actions.