An ethical appraisal of hormesis: toward a rational discourse on the acceptability of risks and benefits.

Hormesis has been defined as a dose-response relationship in which there is a stimulatory response at low doses but an inhibiting response at high doses, resulting in a U- or inverted U-shaped dose response. Until now, regulatory agencies have been reluctant to address this new insight or adjusted their routines for regulating such substances. Should regulators change their principles of decision making and standard setting in the light of the new insights from hormesis research? To answer this question, it is essential to review the ethical implications of hormesis in risk assessment and management. What kind of values should govern the regulation of substances and radiation that may cause positive and negative impacts at the same time (depending on dose and individual variability)? This article tries to address this problem. It deals with the basic ethical principles and foundations of risk management and introduces the essentials of ethics and the application of ethical principles to judging the acceptability of risks to humans and the environment. It will also discuss the merits of an analytic deliberative approach to evaluating complex risks and address the application of this discursive methods to risk management taking into account the hormesis challenge.