Record Display for the EPA National Library Catalog


Main Title U-Shaped Dose-Response Curves: Their Occurrence and Implications for Risk Assessment.
Author Davis, J. M. ; Svendsgaard., D. J. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Environmental Criteria and Assessment Office.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/171;
Stock Number PB91-115808
Additional Subjects Epidemiology ; Toxicology ; Lead(Metal) ; Nervous system disorders ; Children ; Blood ; Reprints ; Dose response relationships ; Risk assessment
Library Call Number Additional Info Location Last
NTIS  PB91-115808 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 15p
A class of curvilinear dose-response relationships in toxicological and epidemiological studies may be roughly described by 'U-shaped' curves. Such curves reflect an apparent reversal or inversion in the effect of an otherwise toxic agent at a low or intermediate region of the dose continuum. Several examples of U-shaped dose response functions are presented to illustrate the variety of agents and end points that can follow this form. Such findings are not thought to represent a unitary phenomenon, but may be explained through numerous possible principles or mechanisms, some of which are illustrated and discussed in general terms. U-shaped dose-response curves raise important issues for toxicological and environmental health risk assessments, particularly in the identification of no-observed-effect levels and in the evaluation of multiple outcomes and trade-offs between potential risks and benefits of a given agent. It is especially important to avoid focusing exclusively on an apparent improvement in one end point and failing to consider other, possibly deleterious effects of the same agent.