Statement from the Perchlorate Information Bureau (PIB): California’s Proposed Revision to Perchlorate Public Health Goal is Unnecessary

January 10, 2011

SACRAMENTO, Calif., Jan. 10, 2011 /PRNewswire/ — The best available science overwhelmingly points to the conclusion that California’s current perchlorate public health goal (PHG) of 6 parts per billion in drinking water is exceptionally conservative and highly protective of public health. California’s proposed decision to lower the PHG to 1 part per billion would jeopardize water supplies and increase costs for water consumers statewide without any corresponding public health benefit.

Early Friday, the Office of Environmental Health Hazard Assessment (OEHHA) released its draft public health goal (PHG) of 1 part per billion (ppb) for perchlorate in drinking water. A 45-day public comment period begins today. Comments on the proposal will follow a comprehensive review of the draft.

Regrettably, the best available and most credible science was not incorporated into the proposal.

  • The National Academy of Sciences (NAS) found in its landmark 2005 report that perchlorate levels as high as 245 ppb in drinking water have no effect on the body. California’s PHG is already 40 times lower than this recognized “no effect” level.
  • The proposed revised PHG was based on a human clinical study in 2002 (Greer study). The authors measured the most sensitive end point in healthy adults and determined the No Observable Effect Level (NOEL). In 2005, the NAS recommended the NOEL, which is the equivalent of 245 ppb in drinking water, and applied a “safety factor” of 10 to be protective of the most sensitive populations, the fetuses of pregnant women. However, the foundational science of perchlorate remains unchanged and the existing PHG of 6 ppb already represents a preponderance of caution for health protection of all populations.

Public health protection is of the utmost importance and the science on perchlorate has been abundantly clear for more than five decades: trace levels found in the environment do not pose a threat to public health.

California’s announcement sets in motion an additional regulatory process by which the state standard for perchlorate in water could be lowered to 1 ppb from its current 6 ppb. Doing so would necessarily entail substantial costs for water purveyors and consumers(1) and take more water supplies offline – all at a time when the state (most especially farmers in the Central Valley) is already facing historic, severe drought and massive reductions in water supplies.

California cannot afford to waste scarce public resources and further burden its economy to move forward with regulations that are not scientifically justified as protecting public health.

Relevant Background For Reporters and Editors:

  • NAS Report: In 2005, a special panel of the National Academy of Sciences(NAS) took the unusual step of suggesting a reference dose (RfD) for perchlorate. The RfD is essentially the daily amount of exposure to a compound that can be considered safe for a lifetime. Standard EPA practice is to determine what level of exposure causes an adverse effect and then apply safety factors to that number to calculate the RfD. As a precaution — no adverse effect level has been identified — NAS took the unprecedented step of starting with a non-adverse effect. NAS further applied a safety factor of ten to this non-adverse effect level to suggest a perchlorate RfD of 24.5 parts per billion.
  • Exposures above the RfD do not immediately equate to a health risk: It’s important to understand that exposure to levels above 24.5 ppb, if it occurs, does not suggest a health risk. According to the NAS, you have to have ten times the reference dose to even have a measurable effect, and NAS emphasizes that this first effect is non-adverse. Therefore, any exposure above the reference dose, if it occurs, must be considered in the context of either a non adverse effect, or no effect at all.

For more on this topic, visit www.perchlorateinfo.org.

The Perchlorate Information Bureau is supported by Aerojet, American Pacific Corporation, ATK, and Lockheed Martin. These companies have worked cooperatively with the U.S. Environmental Protection Agency to increase scientific and medical understanding of perchlorate’s risk to human health.

(1) See reports and information available at http://www.perchlorateinformationbureau.org.php5-18.websitetestlink.com/economic-impact

SOURCE Perchlorate Information Bureau

Source: newswire

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