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In late 2007, faculty at the Albert Einstein College of Medicine published a study regarding high doses of perchlorate and breast milk in rats. This study should be evaluated in the context of the following facts:

  • This study was based on injecting enormous doses of perchlorate (10 µmoles) into lactating rats. To put this in comparable human terms, a typical 70 kg (154 pound) adult who drinks 2 liters of water per day would have to consume water containing more than 100,000 parts per billion (ppb) perchlorate to get an equal dose. It is extremely unlikely that anyone could be exposed to those levels.
    • No public drinking water systems contain anything close to the levels of perchlorate used in this study. In 2006, the U.S. Environmental Protection Agency published research finding that, where perchlorate was detected, it was at an average of 9.85 ppb (Source: EPA Unregulated Contaminant Monitoring Regulation [UCMR] data).
    • Put another way, the study dose is nearly 4,300 times greater than the National Academy of Sciences (NAS)-proposed Reference Dose for perchlorate (0.7 µg/kg-day, or about 24.5 ppb) - which included unprecedented "safety factors" - that NAS determined to be safe for everyone, including the most sensitive populations.
  • The National Academy of Sciences (NAS) accounted for the presence of perchlorate in breast milk when it recommended its perchlorate reference dose in January 2005. As noted, the NAS recommended reference dose, 24.5 ppb, includes a ten-fold safety factor, which, in an abundance of caution, was applied beyond the level NAS determined has no adverse effects.
    • The NAS recommendation was based on a variety of studies spanning several years. In addition, one study that was examined but not considered in the NAS review (because only preliminary results were available at the time) was Tellez, et. al, a study conducted in Chile, where perchlorate is naturally present in drinking water. In that study, perchlorate concentrations in breast milk were measured as high as 103 ppb, with no adverse effects noted. Links to Tellez, et. al and other studies on perchlorate and pregnant women, children and newborns can be found at http://www.councilonwaterquality.org/science/studies.html
  • Scientific awareness of the presence of perchlorate in breast milk is not new. Several studies detecting perchlorate in breast milk were published prior to the NAS review in 2005. At the time, those studies had raised questions among nursing mothers, prompting an international panel of experts convened by the Penn State Milton S. Hershey Medical Center College of Medicine and the Breast Feeding Task Force of Greater Los Angeles to both issue statements that breast feeding remains the best source of nutrition for newborns and infants. More recently, the American Thyroid Association issued a press release indicating "Contrary to Previous Studies, Low Levels of Perchlorate Exposure Are Safe for Pregnant Women." Links to the above referenced statements are provided below.