Undisclosed Conflicts of Interest, Atrazine, and Cancer
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Here to Add Comment Subject: Undisclosed Conflicts of Interest, Atrazine, and Cancer
Date:
Wed, 18 Dec 2002
08:31:50 -0500
From:
Stephen Tvedten <steve@getipm.com>
Organization: Get Set Inc. (www.getipm.com)
To: Paul Helliker <phelliker@cdpr.ca.gov>
Director, State of California, Department of Pesticide
Regulation
cc: Christine Whitman whitman.christine@epa.gov
Last month's J OCCUP ENVIR MED contained a paper concluding, "There is no epidemiologic or other information that clearly supports a causal relation between atrazine and prostate cancer." Nowhere in the publication is it disclosed that the manufacturing plant whose work force was studied was owned by Syngenta; nor is it disclosed that by the report's authors that the work was financially sponsored by Syngenta, the world's largest pesticide producer.
Buried in the text is a brief note that with an additional 2 years of follow up (1998-99), there were in all 11 incident cases of prostate cancer in a plant employee work force in which 1.8 cases would have been expected (SIR = 613, CI = 306-1096). In the report abstract, the smaller prostate cancer excess found in the workers through 1997 is attributed to prostate specific antigen screening of the workers. This actively employed group had on average a duration of exposure of 10.6 years; their experience was diluted in the abstract and concluding discussion section of the report with the experience of almost twice as many contract employees whose mean duration of exposure was only around 2 years. By the end of 1997, the median time of follow-up since hire was 18 years for the plant employees and only under 12 years for the contract workers.
Most of these data were first coughed up by the company and its consultants in October of 2001, in response to the US EPA's demand for Syngenta's data on prostate cancer in its workers. EPA's request was prompted by the Natural Resources Defense Council, based on an internal corporate document alluding to these cancers in 1999 that had been presented to EPA by the lawyers who obtained it in pre-trial discovery. NRDC has asked EPA to conduct an investigation of Syngenta for delaying notification of this information on this herbicide so widely used in the US. Atrazine is banned and severely restricted in many European countries, evidently based on environmental persistence, endocrine disruptive activity, and carcinogenicity in experimental studies.
The lack of follow-up data beyond 1997 of the other-cancer incidence of the workers is also troubling, given that colorectal, breast, bladder cancers, and non-Hodgkins lymphomas were observed only among the company employees.
The publication of such a study in a journal once nicknamed "The Journal of Negative Epidemiology" is disappointing, if not new. However, one would think that even JOEM would by now have in place some requirements for disclosure of financial conflicts of interest for authors who prefer to list only their academic affiliations. If the journal has such requirements, what went wrong?
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Paul MacLennan, Elizabeth Delzell, Nalini Sathiakumar, Susan L. Myers, William Grizzle, Vivien W. Chen, Xiao Cheng Wu. "Cancer Incidence among Trazine Herbicide Manufacturing Workers", J OCCUP ENVIRON MED 44:1048-1058, 2002).
Barry I. Castleman, ScD
Environmental Consultant
bcastle@bcpl.net
410-448-2648
2412 Pickwick Rd
Baltimore MD 21207 USA
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