title: Reference dose (RfD): the possible impact of hormesis.
abstract: A fictitious US Environmental Protection Agency Administrator in the year 2005 is confronted with making a risk management decision on a chemical that exhibits an unambiguous hormetic effect in an animal system. Dose-response curves for average humans and sensitive humans are derived from the animal data. The question is posed: What should the reference dose (RfD) be in this case? A series of outstanding scientific and policy questions are discussed that have a bearing on the answer. The concept of the 'regulatory dose (RgD)' is revived to address, if not resolve, the issue.
authors.affiliation: Science Advisory Board (1400), US Environmental Protection Agency, Washington, DC 20460, USA. barnes.don@epa.gov
authors.forename: D G
authors.initials: DG
authors.lastname: Barnes
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000009:adverse effects*; D006801:Humans; D019055:No-Observed-Adverse-Effect Level; D018570:Risk Assessment / Q000379:methods; D014481:United States; D014484:United States Environmental Protection Agency
chemical_list: D004785:Environmental Pollutants