[CPEO-MEF] California explains perchlorate health goal

[Lenny Siegel <lsiegel@cpeo.org>]

Development of a Health-Protective Drinking Water Level for Perchlorate

David Ting, Robert A. Howd, Anna M. Fan, George V. Alexeeff
Office of Environmental Health Hazard Assessment
California Environmental Protection Agency
Environmental Health Perspectives-in-Press
(January, 2006)

Abstract

We evaluated animal and human toxicity data for perchlorate and 
identified reduction of  thyroidal iodide uptake as the critical 
endpoint in the development of a health-protective  drinking water level 
(also known as the Public Health Goal or PHG) for the chemical.   This 
work was done under the drinking water program of the Office of 
Environmental  Health Hazard Assessment (OEHHA) of the California 
Environmental Protection  Agency.  For dose-response characterization, 
we applied benchmark-dose modeling to  human data provided by Greer et 
al. (2002) and determined a point of departure (the 95%  lower 
confidence limit for 5% inhibition of iodide uptake) of 0.0037 
mg/kg-day.  A PHG  of 6 ppb was calculated by using an uncertainty 
factor (UF) of 10, a relative source  contribution (RSC) of 60 percent, 
and exposure assumptions specific to pregnant women.   The California 
Department of Health Services will use the PHG, together with other 
considerations, such as economic impact and engineering feasibility, to 
develop a  California Maximum Contaminant Level (MCL) for perchlorate. 
We consider the PHG  to be adequately protective of sensitive 
subpopulations, including pregnant women, their  fetuses, infants, and 
people with hypothyroidism.

To download the article, go to
http://ehp.niehs.nih.gov/docs/2006/8684/abstract.html
--
Lenny Siegel
Director, Center for Public Environmental Oversight
c/o PSC, 278-A Hope St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/961-8918
http://www.cpeo.org

_______________________________________________
Military mailing list
Military@list.cpeo.org
http://www.cpeo.org/mailman/listinfo/military