2009 CPEO Military List Archive

From: Lenny Siegel <lsiegel@cpeo.org>
Date: Sat, 1 Aug 2009 19:33:22 -0700 (PDT)
Reply: cpeo-military
Subject: [CPEO-MEF] PERCHLORATE: Massachusetts calls for protective standard
Drinking Water Standard for Perchlorate

Tsedash Zewdie, Clifford M. Smith, Michael Hutcheson, and Carol Rowan-West
Environmental Health Perspectives Online
July 13, 2009


Objective: Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy.

Data Sources: MA Department of Environmental Protection (DEP) scientists, with input from a Scientific Advisory Committee (SAC), assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered as were data on perchlorate in drinking water disinfectants.

Data Synthesis: We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life-stages. A health protective RfD (0.07 [micro]g/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 [micro]g/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens.

Conclusions: Current data indicates that perchlorate exposures to sensitive life-stages attributable to drinking water should be minimized and supports the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggest that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed.


To download the original, complete abstract or the entire article, see


Lenny Siegel
Executive Director, Center for Public Environmental Oversight
a project of the Pacific Studies Center
278-A Hope St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/961-8918

Military mailing list

  Prev by Date: [CPEO-MEF] HEALTH, REUSE: Former NASA plant, Downey, CA
Next by Date: [CPEO-MEF] PERCHLORATE: EPA seeks comments, focuses on children
  Prev by Thread: [CPEO-MEF] HEALTH, REUSE: Former NASA plant, Downey, CA
Next by Thread: [CPEO-MEF] PERCHLORATE: EPA seeks comments, focuses on children

CPEO Lists
Author Index
Date Index
Thread Index