2005 CPEO Military List Archive

From: lsiegel@cpeo.org
Date: 19 Jan 2005 18:19:14 -0000
Reply: cpeo-military
Subject: [CPEO-MEF] EWG - "Second Thoughts on Perchlorate Study" and its coverage
Environmental Working Group


National Academy Panel Scientists Wonder Why
Some Reporters Got The Story Wrong

OAKLAND, Calif., Jan. 19 - Last week, a National Academy of Sciences
(NAS) panel released a long-awaited report on health effects of the
toxic rocket fuel chemical perchlorate. Some of the U.S. news media
reported the NAS found the chemical is dramatically safer than
previously thought, so Americans shouldn't be too worried about its
widespread occurrence in drinking water supplies.

Since its release, NAS panel members have made it clear their findings
do not set safe drinking water levels of perchlorate, which can disrupt
production of thyroid hormones needed for growth and development. They
say other factors - the heightened risk to infants and the added
presence of perchlorate in milk and food - must be considered that would
result in a drinking water standard nearly as low as any proposed or
adopted by federal or state regulators. 

Evidence that many reporters got the perchlorate story wrong comes from
several sources:

* An e-mail, obtained by the Environmental Working Group (EWG), from the
NAS panel chairman to California health scientists, saying "[O]ur
recommendation dealt with a dose from all sources . . . and this should
be corrected for the weight of the individual." He said he tried to set
the record straight "when we saw how often the press got it wrong," but
by then most stories had been published or broadcast.

* A memo from the American Water Works Association advising its 4,700
member utilities that a drinking water standard based on the NAS
findings could be as low as 1.7 parts per billion (ppb) - almost
identical to the standard proposed by Massachusetts, the most stringent
perchlorate standard proposed anywhere.

* A public radio interview in which a scientist from the NAS panel,
asked if the findings must be adjusted to reflect infants' lower body
weight and additional perchlorate exposures besides drinking water,
replied: "[A]bsolutely correct."

EWG has also analyzed dozens of news reports about the study to
determine where mistakes were made and why. Our analysis suggests that
at least some of the blame falls to the Academy's press release, which
said NAS recommended a reference dose (RfD) that was 23 times weaker
than the reference dose in EPA's 2002 perchlorate risk assessment. 

Based on that recommendation, many reporters calculated on their own
that a drinking water standard would also be 20 or more times higher
than the EPA had recommended. But there were problems with that approach:

* EPA never recommended a drinking water standard. The 1 ppb widely
reported as the EPA "standard" was actually a hypothetical extrapolation
from the Agency's RfD - without the consideration of added factors. 

* Many reporters didn't seem to understand, and the NAS release did not
explain, the differences between a drinking water standard and a
reference dose. An RfD is the safe level per unit of body weight, and
the level considered safe to consume from all sources. By law, drinking
water standards must consider the lower body weight of infants, and when
exposure comes from additional sources, a drinking water standard is set
lower to keep overall levels down. 

EWG has written to the NAS, requesting that they issue a statement
clarifying their findings for federal and state regulators who will set
drinking water standards. 

"Perchlorate polluters have already begun a PR and lobbying campaign to
persuade the public, elected officials and regulators that the Academy
decided that higher levels of perchlorate in drinking water are safe for
even infants and nursing mothers," EWG President Ken Cook wrote. "If the
record isn't set straight, we could end up with standards that leave
millions of people at risk." 


For the entire original release, see


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
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