Letters to the Editor
Paustenbach, Dennis J.
ChemRisk, Inc. San Francisco, CA email@example.com (Paustenbach)
To the Editor:
The commentary by Smith1 praising the Beaumont et al reanalysis2 of original work by Zhang et al3-5 implied inappropriate behavior regarding the Zhang and Li 1997 article.5,6 A separate manuscript7 discussing the shortcomings of the reanalysis has been published by researchers who studied the JinZhou pollution incident under Dr. Zhang's guidance. The main points of Smith's commentary that may have misled readers are as follows.
First, Smith1 suggests there was a reversal of scientific conclusions between the 1987 and 1997 publications of Dr. Zhang.4,5 However, both papers identified excess cancer risks in the agricultural villages with groundwater chromium(VI) contamination. The 1997 analysis5 added dose-response considerations identified by Zhang in 19803 that were not included with the brief 1987 synopsis.4 The 1997 paper was simply a more complete account of Zhang's earlier research, and it is not fairly described as a “reversal.”
Second, Smith1 implies that some conflict of interest was behind the 1997 paper5 by suggesting it was “the work of a US consulting firm, ChemRisk, which had been hired by industry clients with liability for chromium pollution.” To the contrary, the translations summarizing Zhang's original research from 19803 did not make it into our work, and industry clients took no part in creating or editing the 1997 manuscript.5 Dr. Zhang had sole authority on authorship and content, signed a permission letter for journal submission including his contact information, and wrote to sincerely thank my colleagues for their assistance.8 Unfortunately, it is unclear that this information was reviewed and given serious consideration prior to the editorial retraction of the 1997 paper5 in 2006.6 Coauthor ShuKun Li separately published her objections9 to that overzealous action on behalf of her deceased colleague.
Third, Smith cites a commentary10 that speculates on the motivations of Zhang and colleagues and describes misconduct allegations by Beaumont and trial attorneys as “evidence.” Contrary to the claims of the trial lawyers,11 Dr. Zhang never claimed that his research proved chromium(VI) ingestion caused cancer.3-5
Smith1 suggests that an epidemiologist's “ultimate nightmare” is being unable to adjust rate data properly even for age and sex. In my view, “ultimate nightmare” more aptly describes the continued dissemination1,10,11 of false misconduct allegations. Conflicts of interest at some level can be assigned to almost any scientific researcher,12 so it is important that opinions about differing scientific interpretations of data should be limited to the basis for those opinions, and not to innuendo about impropriety.
Dennis J. Paustenbach
San Francisco, CA
1. Smith A. Hexavalent chromium, yellow water, and cancer, a convoluted saga. Epidemiology. 2008;19:24–26.
2. Beaumont JJ, Sedman RM, Reynolds SD, et al. Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water. Epidemiology. 2008;19:12–23.
3. Zhang J, Li X. Study of the effect of environmental pollution in the Jinzhou area on residents' health: I Mortality analysis. Jinzhou Disease Control and Prevention Station; 1980. PDF of original Chinese document and certified translation to English available at http://www.chemrisk.com/public/Zhang
4. Zhang J, Li X. Chromium pollution of soil and water in Jinzhou (Chinese language with English abstract). Zhonghua Yu Fang Yi XueZa-Zhi. (Chinese Journal of Preventive Medicine.) 1987;21:262–264.
5. Zhang J, Li SK. Cancer mortality in a Chinese population exposed to hexavalent chromium in water. J Occup Environ Med. 1997;39:315–319.
6. Brandt-Rauf P. Editorial retraction (of Zhang and Li. J Occup Environ Med. 1997;39:315-319). J Occup Environ Med. 2006;46:749.
7. Kerger BD, Butler WJ, Paustenbach DJ, et al. Cancer mortality in Chinese populations surrounding an alloy plant with chromium smelting operations. J Toxicol Environ Health, Part A. 2009;72:329–344.
8. Zhang JD. Correspondence dated June 9-10, September 6, and November 18, 1995. PDF of original Chinese document and certified translation to English available at http://www.chemrisk.com/public/Zhang
10. Egilman D. Scout. Corporate corruption of science- the case of chromium(VI). Int J Occup Environ Health. 2006;12:169–176.
11. Pfaff D. Plaintiff: PG&E settled rather than look bad. Daily Journal; February 7, 2006.
12. Rothman K. Conflict of interest. The new McCarthyism in science. JAMA. 1993;269:2782–2784.
© 2009 Lippincott Williams & Wilkins, Inc.