Environmental Working Group
December 23, 2005


How PG&E's Scientists-For-Hire Reversed Findings of Cancer Study

Part 1: Executive Summary

A consulting firm hired by Pacific Gas & Electric Co. (PG&E) to fight
the "Erin Brockovich" lawsuit distorted data from a Chinese study to
plant an article in a scientific journal reversing the study's
original conclusion that linked an industrial chemical to stomach
cancer, according to documents obtained by Environmental Working Group

The chemical was hexavalent chromium, or chromium-6 (commonly
abbreviated Cr+6 or Cr VI). In the Brockovich lawsuit, residents of
Hinkley, Calif., sued PG&E for dumping chromium-6 in their tap water
-- the basis for the Julia Roberts film released in 2000. The
deception occurred in 1995-97, and before the article's publication
PG&E paid $333 million to settle the case, but the point is hardly

The question of whether chromium-6 in drinking water causes cancer is
at the center of an ongoing lawsuit against PG&E by residents of
another small California town, again represented by Brockovich's law
firm. Scientists and regulators -- including the U.S. Environmental
Protection Agency -- have cited the fraudulent article in research and
in setting safety standards. And the consulting firm that produced and
placed the article continues to do risk assessments and other projects
for corporate and government clients, including the Department of
Energy and the Centers for Disease Control.

The Wall Street Journal reported today that the San Francisco-based
consultants, ChemRisk, "conceived, drafted, edited and submitted to
medical journals" a "clarification" of the Chinese study, according to
documents filed in another chromium lawsuit against PG&E. They did so
despite a letter of objection from the Chinese scientist who led the
original study, calling their reversal of his findings an
"inappropriate inference."

Through the state Public Records Act, EWG has obtained from the
California Office of Health Hazard Assessment (OEHHA) the documents
that tell the story. It's a story of science for sale, and of how far
some industrial polluters will go to manipulate science for their own

Medical Journal and CDC Urged to Take Action

The fraudulent "study" was published in the Journal of Occupational
and Environmental Medicine, a peer-reviewed publication of the
American College of Occupational and Environmental Medicine. EWG has
written the journal's editors urging them to set the record straight
and bar the scientists who were involved in the deception from its

"The scientific community must be notified that a paper circulating in
the published literature is fraudulent, the paper must be retracted,
and those responsible for the incident must be appropriately
disciplined," EWG's letter to the journal says. [link to PDF]

EWG has also written to the Centers for Disease Control (CDC), which
recently renewed ChemRisk's multi-million dollar contract for a key
project at the Los Alamos National Laboratory, urging the agency to
take prompt action against the company.

"ChemRisk's current... contract must be cancelled and the firm barred
from seeking future contracts from the CDC or other government
agencies," says EWG's letter to the CDC. [link to PDF]

In 1987, Drs. JianDong Zhang and XiLin Li published a study in a
Chinese medical journal that found "significant excess of overall
cancer mortality" in five rural villages in Liao-Ning province, where
the groundwater was contaminated with chromium-6 from a chromium ore
processing facility. [1] But ten years later, in April 1997, the
Journal of Occupational and Environmental Medicine (JOEM) published an
article under the byline of Zhang and ShuKun Li (the reason for the
different name of the second author is unclear) that reversed that
conclusion, stating that the data from Liao-Ning province "do not
indicate an association of cancer mortality with exposure to Cr+6
contaminated groundwater." [2]

To all appearances, the 1997 JOEM article was the result of a
researcher conducting a more thorough analysis of the original data
and revising the findings accordingly, not an uncommon practice in
science. But nothing could be further from the truth.

The truth is told in court documents and depositions filed in another
lawsuit against PG&E over chromium-6 contamination of drinking water,
brought by residents of Kettleman City, Calif., which is scheduled to
come trial in early 2006. Kettleman City and Hinkley are the sites of
PG&E stations that pump natural gas from a Texas pipeline to
California customers. Chromium-6 was used to cool the natural gas,
then dumped in unlined ponds which leached the contaminant into

ChemRisk 'Study' Concealed Cancer Link

The documents show that ChemRisk employees -- with the knowledge of
PG&E's attorneys -- conducted their own analysis of Zhang and Li's
data, deliberately ignoring statistics on cancer in the province that
pointed to an association with chromium-6. They then wrote and
submitted the article for publication without disclosing that they
worked for ChemRisk or that PG&E had paid for the new "study." Zhang,
now deceased, was a paid consultant to the project, but the documents
suggest his biggest contribution was providing his original data.
Nowhere in the published article are the names of the ChemRisk
employees who worked on it, or any indication that the paper was part
of PG&E's legal defense strategy.

Documents and depositions indicate that most of the work was done by
ChemRisk scientists Bill Butler and Tony Ye with help from several
other employees. The cover letters and other correspondence with JOEM
have not surfaced, but presumably identical correspondence with
another journal show how ChemRisk was able to avoid having its
connection to the article known. Although Ye typed the cover letter at
work, it was printed on plain paper rather than company letterhead;
the return address was Ye's home, not his employers' offices. (Before
the article was published, Butler and Ye left to form their own
company, Environmental Risk Associates, which continued to bill PG&E
for work on the article.)

At the time, ChemRisk was a division of McLaren/Hart Environmental
Engineering, an international consulting firm that went bankrupt in
2001. Today -- under different ownership but the same executive
officer -- ChemRisk is based in San Francisco with offices in Boston,
Pittsburgh, Houston and Boulder, Colo., "providing state-of-the-art
toxicology, industrial hygiene, epidemiology, and risk assessment
services to organizations that confront public health, occupational
health, and environmental challenges." [3]

Among its many corporate and government clients, ChemRisk holds a
contract from the Department of Energy and the Centers for Disease
Control (CDC). Under this contract, believed to be for 5 years and $5
million a1, ChemRisk will analyze hundreds of thousands of documents
accounting for all chemical and radioactive materials released from
Los Alamos National Laboratory in six decades of nuclear weapons work.

The founder and president of ChemRisk is Dennis Paustenbach, who was
CEO of McLaren/Hart when it owned ChemRisk. [5] Paustenbach has made
a career out of consulting and testifying on behalf of dozens of big
polluters including PG&E, ExxonMobil and Dow Chemical. [6,7]
Independent scientists blasted his 2002 appointment to a CDC committee
that assesses the health effects of chemicals as part of a Bush
Administration pattern of packing environmental panels with industry-
friendly experts. [8] The Newark Star-Ledger, in an investigation of
Paustenbach's role in weakening chromium standards in New Jersey, said
he "rarely met a chemical he didn't like." [7]

Getting to the bottom of ChemRisk's misdeeds is not just an intriguing
scientific detective story. Zhang and Li's original work remains the
only study of people ingesting chromium-6 in their drinking water.
[9] The JOEM article reversing its findings was cited by the U.S.
Environmental Protection Agency in a 2001 assessment of whether
chromium-6 should be allowed in a wood preservative, and by the Agency
for Toxic Substances and Disease Registry in a 2000 report that said
elevated cancer rates in Liao-Ning "probably reflect lifestyle or
environmental factors rather than exposure to chromium." [10,11]

Most significantly, the article was cited prominently by a scientific
panel whose 2001 report forced California health officials to revise a
recommendation for how much chromium-6 should be allowed in drinking
water. [12] The Office of Environmental Health Hazard Assessment
(OEHHA) had recommended a level based on the assumption that
chromium-6 in drinking water causes stomach cancer, but the panel
pointed to the JOEM article as evidence to the contrary. Not
coincidentally, Dennis Paustenbach was a member of the panel, although
he resigned after his ties to chromium polluters were exposed. [13]
(OEHHA's revised recommendation for chromium-6 in drinking water is
scheduled to be released this fall and will not rely on the
discredited 1997 "study". [14])


a1 CDC would not release the terms of the contract without a Freedom
of Information Act request which could not be completed under
deadline. This figure comes from a New Mexico source close to the

Part 2: The Debate Over Chromium Standards

Chromium is a naturally occurring metal used in steel manufacturing,
leather tanning, welding, and the production of dyes, pigments and
alloys. It is also often used to plate metal surfaces, is a major
component of the pesticides used in pressure-treated lumber, and was
also a common anti-corrosive agent used in cooling towers until the
federal government banned the practice in 1990. [15] But not all
chromium is created equal.

Trivalent chromium, or chromium-3, is a necessary nutrient naturally
present in many foods and added to many vitamins as a dietary
supplement. The other major type, chromium-6, is produced mainly
through industrial processes, enters living cells much more readily
than trivalent chromium, and is known to cause a variety of acute
health effects when ingested at high levels, including vomiting,
convulsions, ulcers, kidney and liver damage. [15,16]

There is no question that chromium-6 is a dangerous chemical. The
International Agency for Research on Cancer, the EPA, and the National
Toxicology Program all say chromium-6 causes cancer when inhaled.
[16,17,18] Last year the Occupational Safety and Health Administration
(OSHA) announced it would lower its safety standard for inhaled
hexavalent chromium by a factor of more than 50 after it became clear
that the current standard was too high to protect workers. [19]

How dangerous chromium is in drinking water is more controversial.
Scientists agree that much chromium-6 is converted to the safer
chromium-3 by stomach acid. But how quickly, and how much? Once inside
a cell, chromium-6 is extremely toxic. If cells take up chromium-6
before it converts to chromium-3, it has the potential to cause many
health problems, including cancer. Recent research has shown that
orally ingested chromium-6 penetrates to tissues and organs throughout
the body. [20]

In 1977, California set a safety standard of 50 parts per billion
(ppb) for total chromium (which includes all chromium compounds) in
drinking water. The EPA subsequently adopted the same standard, then
in 1991 weakened it to 100 ppb. California disagreed with the looser
standard and retained its original 50 ppb limit, the same guideline
used by the World Health Organization. [21,22]

But in the late 1990s the California Environmental Protection Agency
(Cal-EPA) realized that even this level was still too high to
adequately protect human health and began to re-examine the standard.
[14,21] In 2001 the state Legislature passed a law requiring the
Department of Health Services (DHS) to set a drinking water standard
just for chromium-6. [14] The standard is more than a year overdue,
but when it is set California will be the first state to specifically
regulate chromium-6 in drinking water.

To set a standard, the first step was for OEHHA to determine the level
of chromium-6 in water that would be safe for all Californians to
ingest over the course of a lifetime with no adverse effects. To
establish this Public Health Goal (PHG), OEHHA reviewed all available
toxicity information, including the 1997 JOEM article. The paper was
important because it was the only drinking water study in the
scientific literature to report on specific types of cancer. [9]
Second, the panel of scientists assigned by the University of
California -- including Paustenbach -- to provide OEHHA guidance had
given the study great emphasis. [12] OEHHA wasn't looking for a
scientific fraud or a polluter's coverup -- but that's exactly what it

Part 3: Chromium Pollution in JinZhou

In 1959 the JinZhou Alloy Plant, located in a rural area in Liao-Ning
province in northeastern China, began processing chromium ore. Its
poor waste disposal practices quickly led to massive chromium-6
pollution. The plant not only released chromium-laced wastewater into
a neighboring dry riverbed that cut through nearby villages, it also
dumped thousands of tons of solid waste onto bare ground around the
plant site. Rainwater percolating through the waste piles leached
chromium-6 into the groundwater. [2]

When investigators from the JinZhou Health and Anti-Epidemic Station
began sampling well water from nearby villages in early 1965, they
discovered that almost a third of the wells in the two villages
closest to the plant were contaminated with chromium-6. By the end of
the year, the incidence of contamination had risen dramatically in
these two villages, and sampling in three more distant villages
revealed polluted drinking water and irrigation wells as well. By the
1970s, the contamination plume had spread to more distant villages.
[23] The contamination wasn't contained until the early 1980s, when a
concrete barrier was installed around the plant. [2]

Health surveys conducted from 1965 through 1974 found that residents
in all five contaminated villages suffered from a variety of ailments
associated with chromium-6 exposure: mouth ulcers, diarrhea, abdominal
pain and vomiting. JianDong Zhang and XiLin Li, scientists assigned to
the health station, published a series of articles in Chinese journals
documenting the health problems. [23] Their work culminated in the
1987 paper in the Journal of Chinese Preventive Medicine that linked
chromium-6 exposure to the higher rates of cancer found in the
contaminated area. [1] This study has never been published in English,
but the 1997 JOEM article summarized the earlier study's conclusion as
"a significant excess of overall cancer mortality in five Cr+6
contaminated villages combined." [2] The JOEM article, published under
the names of Zhang and ShuKun Li, comes to quite different
conclusions. Its abstract reads:

This report is a clarification and further analysis of our previously
published mortality study regarding groundwater contamination with
hexavalent chromium (Cr+6) in the JinZhou area of China between 1965
and 1978. In our previous report, we stated that a significant excess
of overall cancer mortality was observed (P = 0.04) in five Cr+6-
contaminated villages combined. Further analysis revealed no clear
statistical increase in cancer mortality in the three villages
adjacent to the source of the contamination (P = 0.25), where 57% of
the wells exceeded the European Community safe drinking water standard
of 0.05 ppm Cr+6. These results do not indicate an association of
cancer mortality with exposure to Cr+6-contaminated groundwater, but
might reflect the influence of lifestyle or environmental factors not
related to Cr+6. Further follow-up of this cohort is recommended. [2]

The 1997 study acknowledges that the five villages taken together
still had high cancer rates, but reverses the 1987's study's
conclusion that chromium-6 was to blame. The JOEM paper states that
the villages closer to the chromium-6 plume had lower rates of stomach
and lung cancer than those farther away, and that the cancer rates in
the three villages closest to the source were not significantly higher
than the surrounding province. The article also suggests that the
Agency for Toxic Substances and Disease Registry should revise its
assessment of the 1987 study in light of the new "findings":

"The absence of a dose-response relationship between cancer and Cr+6
clarifies a translation and interpretation of our previous publication
made by the Agency for Toxic Substances and Disease Registry. Although
Cr+6 contamination cannot be ruled out completely as the reason for
the high cancer death rates in these villages, these results do not
support such a relationship." [2]

Part 4: "It's a Small World"

Fast forward to California in August 2001. OEHHA's draft safety level
for chromium-6 in drinking water had been roundly criticized by the
Paustenbach panel, and the agency had withdrawn its recommendation.

OEHHA scientist Jay Beaumont was assigned to look further at the JOEM
article repeatedly cited by the panel. In an email to his colleagues,
after summarizing the two articles, Beaumont pointed out "several
notable limitations and oddities in the Zhang and Li 1997 paper."

Although actual chromium-6 concentrations were available for each of
the villages, Beaumont noted, the authors chose to use distance from
the industrial source as "a surrogate for exposure." The
concentrations would be a better measure, yet Beaumont noted that the
authors provided no reason for not using the actual levels, even
though they were contained in a table included in the paper. He also
noticed that the authors failed to explain how they calculated
distance from the pollution source -- an important detail since some
of the villages are more than a kilometer in width. To top it all, the
paper misused three epidemiologic terms.

Although OEHHA scientists still had little reason to doubt the
article's overall veracity, they began digging deeper. As they looked
more closely at the connection between chromium-6 and stomach cancer,
their doubts grew. The JOEM article looked at stomach cancer death
rates, but didn't compare them to rates in the province, as it did for
rates of total cancer. [25] The article said this questionable
choice was because stomach cancer rates weren't available for the
province. [2] But that's not what Jay Beaumont found.

In an e-mail to OEHHA chief Joan Denton, he wrote: "I checked to see
whether the rates should have been available, and in fact they were
available from the same source from which the investigators obtained
other rates. The age-adjusted stomach cancer mortality rate in the
province was 20.9 per 100,000 per year, while the rate in the
contaminated villages was 37.1." [25: Excerpt Full document]
Overall, OEHHA's analysis showed that stomach cancer rates in the
contaminated villages were 87 percent higher than found in the
surrounding province, and this finding was statistically significant.
Beaumont wrote another OEHHA colleague: "I wouldn't call this
'negative'!" [26: Excerpt Full document]

Confused, OEHHA tried to track the authors down. Beaumont found a Web
page promoting Zhang's rather unorthodox theories on wearing "bio-
ceramic" underwear to protect against breast and prostate cancer.
[27] The Web site said Zhang was a consultant to McLaren/Hart,
ChemRisk's parent company. The CEO of McLaren/Hart, of course, was the
same Dennis Paustenbach who had made the JOEM article a central point
in the scientific panel's critique of OEHHA.

"Dr. Evil"

Paustenbach, who holds a PhD in toxicology, testified for PG&E in the
Hinkley case -- earning fees of $300 an hour -- and once soaked in a
hot tub full of chromium-laced water to try to prove that it was
harmless. [28] The ChemRisk Web site touts his work for the American
Petroleum Institute, Chemical Manufacturers Association and the
Formaldehyde Institute. [3] He is on the editorial board of the
journal Regulatory Toxicology and Pharmacology, which 40 prominent
scientists denounced in 2003 "as a convenient venue for the
publication of industry research." [29]

The Newark Star-Ledger's investigation found that in the 1990s, three
companies responsible for widespread chromium pollution hired
Paustenbach to help them attack the state's strict cleanup standards.
"When state scientists determined chromium caused skin rashes,
Paustenbach's team argued the DEP [Department of Environmental
Protection] was using the wrong testing method. When that argument
failed to convince the department, Paustenbach and his team again did
their own study and used the results to argue that the standard was
too restrictive," reported the Star-Ledger. [30] Over a decade,
Paustenbach's work helped save the companies an estimated $1 billion
in cleanup costs by persuading the state to weaken its chromium
standards from 10 parts per million in soil to more than 6,000 ppm.
When the newspaper asked a former Clinton Administration environmental
official about Paustenbach, he replied: "Ah, Dr. Evil." [7]

Even before he was named to the California chromium-6 review panel,
Paustenbach and his work for chromium polluters was well known at
OEHHA. In 2000, he'd written the agency to argue that the Public
Health Goal should not be based on the assumption that chromium-6 in
drinking water causes cancer. His letter cited the fraudulent 1997
ChemRisk paper, "the only epidemiological study of humans exposed to
Cr(VI) through drinking water," as reporting "no excess in
gastrointestinal cancers" even though levels were well above the
California safety standard. [74: Excerpt Full document]

So when Jay Beaumont found Zhang's Web page saying he was a consultant
for McLaren/Hart, it wasn't hard to put two and two together. In an
email to colleagues, he wrote:

"Thus the money to pay Dr. Zhang likely came from the industrial
clients of McLaren/Hart who have a strong financial interest in the
health effects evidence for Cr6. I don't know what Dr. Zhang was paid
to do by McLaren/Hart, but republishing his study with different
conclusions seems a possibility. It's a small world after all!" [27:
Excerpt Full document]

Part 5: The ChemRisk Documents

The truth was more complicated than that, but Beaumont had uncovered
the basic outline of the fraud. The details of ChemRisk's deception
emerged from documents filed in the Kettleman City lawsuit against

In 1995, PG&E's lawyers had suffered a major setback in the Hinkley
lawsuit: The judge had admitted the 1987 study was an important piece
of evidence that chromium-6 was harmful to human health. [31,32]
Under contract to PG&E, McLaren/Hart-ChemRisk set out to get
additional information that might cast doubt on the study.
McLaren/Hart had offices in China, and employees there managed to
track down the elderly Dr. Zhang, who was retired from the JinZhou
health station, spoke little English and had no computer.

In April 1995, Zhang signed a consultant's contract with McLaren/Hart.
According to the documents, he was initially paid $250 a month to
provide "document review and consultation regarding epidemiology,
groundwater contamination and health effects of chromium." [37] All
told, he was paid less than $2,000; ChemRisk's fees from PG&E's
lawyers were between $20,000 and $30,000. [38,39,40,41]

It's unclear if, or at what point, Zhang knew he was really working
for PG&E. In a 1997 deposition, a ChemRisk scientist named Brent
Kerger, who oversaw the firm's work on the fraudulent study, testified
that he didn't think this information "would be of particular
interest" to Zhang, but that he later told Zhang when asked about it.
[42] But PG&E's attorneys knew McLaren/Hart had retained Zhang, and
why. Asked in the deposition, "Did ChemRisk inform PG&E's counsel that
ChemRisk was involved in getting the Zhang '97 article published?,"
Kerger replied: "Yes, they knew." [43]

Although Zhang worked on the project, ChemRisk was clearly responsible
for most of the work and content of the 1997 paper. An August 1995
memo from Bill Butler describes Zhang's role merely as "research
assistance." [44: Excerpt Full document] In the memo, Butler
complains that: "It is at times difficult to convince Dr. Zhang of the
importance to us of the specific details of his studies so that we can
execute our own analyses." [Emphasis added.] [44: Excerpt Full
document] Kerger later testified that "all of the numerical analyses
that were done with respect to the... cancer death rates... was [sic]
the responsibility of Bill Butler." [45]

"I Guess It Wasn't Standard Practice"

Other testimony revealed that all of the drafts of the article were
typed by Tony Ye -- who was just out of college and seems to have been
assigned to the project because he spoke Chinese -- in English on
ChemRisk computers and changes were made by a ChemRisk word processing
program. [46,47] More than ten early drafts of the paper show
handwritten changes made by ChemRisk employees and the cover pages of
two early drafts of the article actually state that it was "by
ChemRisk," apparently before Ye realized the firm's role should be
covered up. [48,49,50,51,52,53,54,55,56,57,58]

No attempts were made to get the study published in a Chinese-language
journal; it is unclear as to whether a Chinese version of the final
article ever existed or if the final JOEM article was ever sent to
Zhang. [59,60] In a 1996 memo to PG&E's lawyers, ChemRisk's Brent
Kerger lists the JOEM article as one of eight "ChemRisk Chromium
Manuscripts in Peer-Reviewed Scientific Journals." (Notably, it was
the only one that did not list at least one ChemRisk employee as an
author.) [61] ChemRisk actually misspelled Zhang's name on all of
its drafts of the manuscript, on the cover letters sent to journals,
and in the final published article itself.

In December of 1995, ChemRisk finished the final draft of the paper.
Although very early drafts of the paper mentioned ChemRisk's
involvement and a draft cover letter to another journal directed
correspondence to Zhang care of ChemRisk, neither the final manuscript
article nor the final cover letter included any mention of ChemRisk.
[48,49,50,51,52,53,54,55,56,57,58] Rather, the
cover letter was typed on ChemRisk computers but printed on plain
white paper, and directed correspondence to be sent to Tony Ye's home
address. [48: Excerpt Full document, 49: Excerpt Full
document, 63,64] When asked under oath whether this was unusual
procedure, Kerger responded: "I guess it wasn't standard practice."

ChemRisk wanted to get the paper published quickly because PG&E's
negotiations over the Hinkley settlement were coming to a close. The
firm submitted the article to two journals at the same time -- JOEM
and the Archives of Environmental Health -- even though this violated
both journals' policies against simultaneous submissions. [66,67]
In depositions, ChemRisk employees claimed not to know of the
journals' policies, but not only are such policies standard in the
academic world, ChemRisk signed forms promising that the study was not
being considered anywhere else. Compared to ChemRisk's other
deceptions, the simultaneous submission is a minor sin, but evidence
of the firm's willingness to disregard ethics to its clients'

In May 1996, Tony Ye found that the paper had been accepted by both
journals. [68] ChemRisk withdrew the paper from the Archives of
Environmental Health and pursued publication with JOEM. A couple of
weeks later ChemRisk sent the following memo to PG&E's attorneys:

We are pleased to inform you that the short communication regarding
clarification of Dr. Zhang's previous work on cancer mortality in a
Chinese population exposed to Cr(VI) in water was accepted with no
revisions in the Journal of Occupational and Environmental Medicine.
Dr. Zhang's previous paper (which is cited by ATSDR) stated that total
cancer and stomach cancer mortality was significantly elevated in
populations living along the Cr(VI)-contaminated groundwater plume.
This short communication clarifies that the cancer death rates (both
total and stomach cancers) "were not correlated with the degree of
exposure to Cr+6" and that "neither stomach nor lung cancer indicated
a positive association with Cr+6 concentration in well water." [69]

The memo's reference to ATSDR signifies PG&E's concern about the fact
that the Agency for Toxic Substances and Disease Registry had cited
the 1987 Zhang study in support of a connection between chromium-6
exposure in drinking water and cancer. To ChemRisk, this was the
strongest indicator of their success in getting the findings of
Zhang's study reversed.

Zhang died sometime before 2001 so it is impossible to know what he
thought of the final article that bears his name. Much of the language
tempering the study's conclusions in early drafts is absent in the
final article. An earlier draft said: "These results suggest that the
high cancer death rates in this area may be partially attributed to
lifestyle or environmental factors not related to the chromium (VI)
contamination," while the final paper made a much stronger assertion:
"Nonetheless, these results suggest that lifestyle or environmental
factors not related to the chromium (VI) contamination are the likely
source of the variation in these cancer rates." [56: Excerpt Full
document, 2]

Thirteen Ethical and Scientific Flaws

There is evidence Zhang wasn't happy with ChemRisk's analysis. In a
September 6, 1995 memo to Butler, Ye wrote: "Dr. Zhang did not totally
agree with us with the conclusion section" and that he had "to make a
little compromise." [70: Excerpt Full document] But ChemRisk
certainly didn't display any qualms about compromising the standards
of sound science. After reviewing the JOEM paper, the original 1987
Zhang and Li study, translations of Zhang's earlier work published in
China, as well as earlier drafts of the 1997 manuscript, court
depositions, and internal documents obtained through independent
litigation, OEHHA drew up a list of thirteen ways in which ChemRisk
committed ethical or scientific breaches, including:

Failure to disclose who wrote the manuscript.

Failure to disclose that the study was funded by PG&E.

Falsely stating in the published paper that stomach cancer rates
weren't available for the province.

Basing analysis on the level of contamination detected in the wells in
1965, knowing that by the end of that year the picture of
contamination in the wells had dramatically changed.

Ignoring useful data that were readily available. Misrepresenting the
study design in several ways to make it seem stronger.

Failing to disclose key facts about the data presented.

Simultaneous submission to two journals. [71]

The lies, errors, and misrepresentations in the 1997 JOEM article
don't stop even there. EWG's review of court documents and depositions
show that several of the high chromium-6 concentrations reported in
Zhang's original 1987 study were left out of the 1997 paper. [72]
Worse, a graphic reporting chromium-6 concentrations in the wells of
the Chinese village most affected by chromium contamination also
erroneously shows the chromium-6 levels of the wells in a different,
less contaminated village. [73]

In addition, OEHHA pointed out that the "13-year observation period
after the first exposure was relatively short for a study of human
cancer, because many cancers could occur after the end of the
observation period." [71: Excerpt Full document] In other words,
even if all of the analysis had been conducted correctly, a negative
finding between chromium-6 exposure and cancer would still be
considered suspect simply because it often takes longer than 13 years
for cancer to develop after the first exposure to a carcinogen.


[1] Zhang, JianDong and XiLin Li. 1987. [Chromium pollution of soil
and water in Jinzhou]. Zhonghua Yu Fang Yi Xue Za Zhi [J. Chinese
Prevent. Med.] 21(5):262-4.

[2] Zhang, JinDong and ShuKun Li. 1997. Cancer mortality in a Chinese
population exposed to hexavalent chromium in water. JOEM

[3] ChemRisk's website: http://www.chemrisk.com/ Accessed on September
30, 2005.

[4] US Department of Energy and U.S. Department of Health and Human
Services. 2005. Agenda for HHS Public Health Activities (For Fiscal
Years 2005 -- 2010) at U.S. Department of Energy Sites. January, 2005.
Available at: http://www.cdc.gov/niosh/pdfs/hhsdoe_2005-2010.pdf

[5] ChemRisk's website: http://www.chemrisk.com/team/paustenbach.htm
Accessed on September 30, 2005.

[6] Center for Science in the Public Interest. 2005. Integrity in
Science Database. Available at: http://www.cspinet.org/integrity/in
dex.html Accessed on September 30, 2005.

[7] Lane, A. 2004. When corporations need an expert, he gladly answers
the call. Newark Star-Ledger. March 7, 2004.

[8] Weiss, R. 2002. Paustenbach CDC appointment: HHS Seeks Science
Advice to Match Bush Views. Washington Post. Tuesday, September 17,
2002. Page A01.

[9] Deposition of Brent Kerger. Wednesday, December 4, 2002. Volume 1,
page 165, line 3.

[10] US Environmental Protection Agency. 2001. Inorganic Chromium -
Report of the Hazard Identification Assessment Review Committee.
Available at: http://www.epa.gov/oscpmont/sap/2001/october/ar

[11] Agency for Toxic Substances and Disease Registry. 2000.
Toxicological Profile for Chromium. US Department of Health and Human
Services. Available at: http://www.atsdr.cdc.gov/toxprofiles/tp

[12] Chromate Toxicity Review Committee. 2001. Scientific review of
toxicological and human health issues related to the development of a
Public Health Goal for chromium (VI). August 31, 2001. Available at:

[13] Hearing of the California Senate Health and Human Services
Committee. 2003. Possible Interference in the Scientific Review of
Chromium VI Toxicity. February 23, 2003. Los Angeles, CA. Transcript
available at: http://www.sen.ca.gov/health/CHROMIUM_VI_TRANSCRIP
T_28FE B03.DOC

[14] California Department of Health Services. 2005. Chromium-6 in
Drinking Water: Timeline. Available at: http://www.dhs.ca.gov/
ps/ddwem/chemicals/chromium6/Cr+6timeline.htm Accessed on September
30, 2005.

[15] US Environmental Protection Agency. 2000. Hazard summary for
chromium compounds. Available at: http://www.epa.gov/ttn/a

[16] US Environmental Protection Agency, Toxicological Review of
Hexavalent Chromium (CAS No. 18540-29-9), August 1998. Available at:

[17] International Agency for Research on Cancer (IARC). 1990.
Monographs on the Evaluation of Carcinogenic Risks to Humans. Chromium
and Chromium Compounds. Volume 49, 1990. Available at:

[18] National Toxicology Program. 2005. 11th Report on Carcinogens.
Chromium Hexavalent Compounds. Available at:

[19] US Department of Labor, Occupational Safety & Health
Administration. 2004. Occupational Exposure to Hexavalent Chromium;
Proposed Rule. Federal Register: October 4, 2004 (Volume 69, Number
191). Available at: http://www.osha.gov/FedReg_osha_pdf/FED20041

[20] Costa, M. 1997. Toxicity and carcinogenicity of Cr(VI) in animal
models and humans. Crit Rev Toxicol 27(5):431-42.

[21] California Department of Health Services. 2004. Chromium-6 in
Drinking Water: Background Information. Available at: http://www.dh

[22] World Health Organization. 1996. Guidelines for Drinking-Water
Quality, 2nd Ed., Vol. 2. Health Criteria and Other Supporting
Information, Inorganic Constituents and physical parameters, World
Health Organization, Geneva. Available at: http://www.who.int/wa

[23] Office of Environmental Health Hazard Assessment. 2003. Draft
Public Health Goal for Hexavalent Chromium in Drinking Water.
December, 2003. Obtained by EWG through public records request.

[24] Email from Jay Beaumont to George Alexeeff. August 7, 2001.

[25] Email from Jay Beaumont to Joan Denton. October 5, 2001.

[26] Email from Jay Beaumont to Richard Sedman. September 10, 2001.

[27] Email from Jay Beaumont to George Alexeeff, Bob Howd, Ling-Hong
Li, Tom McDonald, Martha Sandy, Richard Sedman and Lauren Zeise.
September 14, 2001.

[28] Bustillo, M. 2003. PG&E Assailed in Hearing Over Chromium 6; The
utility boycotts session in which Erin Brockovich says firm had role
in downplaying health risks of pollutant. Los Angeles Times. March 1,

[29] Polley, MB. 2002. Journal accused of letting industry ties cause
bias. Pesticide & Toxic Chemical News. December 16, 2002.

[30] Lane, Alexander. 2004. Polluters gain as Jersey lifts limit for
toxin. March 7, 2004. Newark Star-Ledger.

[31] Kerger Deposition. Volume 1, page 165, line 7.

[32] Deposition of Brent Kerger. Tuesday, February 18, 2003. Volume 2,
page 327, line 12.

[33] Deposition of Tony Ye. Thursday, December 12, 2002. Volume 1,
page 44, line 21; page 243, line 10.

[34] Kerger Deposition. Volume 2, page 514, line 8.

[35] Deposition of Tony Ye. Friday, December 13, 2002. Volume 2, page
516, line 21.

[36] Kerger Deposition. Volume 1, page 287, line 14.

[37] McLaren/Hart Environmental Engineering Corporation. 1995.
Authorization letter/Task Order. September 11, 1995. Contract between
PG&E and Jian Dong Zhang. Faxed to Tony Ye at ChemRisk. Bates stamps:
TY-0459 and TY-0460.

[38] Letter from to Guang Zhu to Chris Daniels, McLaren Hart
International. November 21, 1995. Bates stamp TY-100.

[39] Kerger Deposition. Volume 1, page 42, line 23.

[40] Kerger Deposition. Volume 1, page 47, line 6.

[41] Ye Deposition. Volume 2, page 369, line 4.

[42] Kerger Deposition. Volume 1, page 216, line 18.

[43] Kerger Deposition. Volume 1, page 43, line 19.

[44] Memo from Bill Butler to Brent Kerger. August 7, 1995. Bates
stamps: WB-0117 to WB-0122. See page 2 of memo.

[45] Kerger Deposition. Volume 1, page 160, line 3.

[46] Ye Deposition. Volume 2, page 516, line 21.

[47] Kerger Deposition. Volume 2, page 514, line 8.

[48] Draft paper with Bates stamps: TY-0102 to TY-0112.

[49] Draft paper with Bates stamps: TY-0089 to TY-0097.

[50] Draft paper with Bates stamps: TY-0469 to TY-0476.

[51] Draft paper with Bates stamps: WB-0215 to WB-0220 and WB-0204 to

[52] Draft paper with Bates stamps: WB-0207 to WB-0209.

[53] Draft paper with Bates stamps: WB-0200 to WB-0203.

[54] Draft paper with Bates stamps: WB-0181 to WB-0184.

[55] Draft paper with Bates stamps: WB-0175 to WB-0179.

[56] Draft paper with Bates stamps: WB-0164 to WB-0167.

[57] Draft paper with Bates stamps: WB-0062 to WB-0070.

[58] Draft paper with Bates stamps: TY-0113 to TY-0119.

[59] Ye Deposition. Volume 2, page 330, line 23; page 361, line 2.

[60] Ye Deposition. Volume 1, page 157, line 20.

[61] Letter from Brent Kerger to Steven Hoch, Esq. May 20, 1996. Also
faxed to Mike Whelan, PG&E May 20, 1996. Bates stamps: BRP 0331 to BRP

[62] Ye Deposition. Volume 2, page 332, line 22.

[63] Ye Deposition. Volume 1, page 64, line 24; page 66, line 16; page
68, line 24.

[64] Kerger Deposition. Volume 2, page 402, line 13.

[65] Kerger Deposition. Volume 1, page 264, line 4.

[66] Fax from Tony Ye to Gwen Corbett. January 24, 1996. Bates stamps
TY-0529 to TY-0530.

[67] Ye Deposition. Volume 1, page 67, line 17.

[68] Memos from Tony Ye to Brent Kerger and Bill Butler. April 19 and
May 20, 1996. Bates stamps TY-0540 and TY-0541.

[69] Memo from Gwen Corbett to Greg Read et al. June 5, 1996. Re:
Acceptance of China Paper. Copied to Brent Kerger. Bates stamp: BRP

[70] Memo from Tony Ye to Brent Kerger. September 6, 1995. Bates
stamps: WB-0173 to WB-0179. See page 1 of memo.

[71] Internal OEHHA memo dated March 28, 2003. Scientific issues
regarding Zhang and Li, 1997. Obtained through public records request.

[72] Kerger Deposition. Volume 2, page 379, line 24.

[73] Kerger Deposition. Volume 2, page 394, line 8.

[74] Letter from Dennis Paustenbach to George Alexeeff. July 17, 2000.

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