Glyphosate Data: Nat. Cancer Institute Scientist Says He Did Not Hold Back Info – DTN

    Herbicide Application. ©Debra L Ferguson Stock Photography

    The scientist who is the subject of a congressional investigation into an international body’s declaration that glyphosate is “probably carcinogenic to humans,” told DTN he did not hold back information that was contrary to the finding.  

    Dr. Aaron Blair, a scientist at the National Cancer Institute (NCI), is alleged to have withheld contrary information from the International Agency for Research on Cancer, or IARC. The agency reached the conclusion on glyphosate in March 2015.

    Earlier this week, Rep. Trey Gowdy, R-S.C., pressed the National Institutes of Health (NIH) for information as to why Blair, of the National Cancer Institute and a senior researcher on the Agricultural Health Study — who also led the IARC’s review of glyphosate — did not share unpublished data with the IARC that showed no cancer connection with glyphosate.

    Gowdy, chairman of the House Committee on Oversight and Government Reform, sent a letter Tuesday to the NIH asking for information about Blair’s activities.

    Congress became involved in questioning the IARC’s decision after it came to light the World Health Organization, or WHO, received funding from the U.S. government.

    IARC relies on published studies as part of its process of examining chemicals and other materials for cancer links.


    Blair told DTN he did not hold back his findings from the Agriculture Health Study.

    “Findings from the AHS were included in the IARC review,” he said. “These were published and showed no association between non-Hodgkin lymphoma and use of glyphosate and this is noted in the IARC monograph.

    “It is the work on an extended follow-up of the AHS on glyphosate that was not complete at the time of the review and, following IARC rules, these data were not included. But the negative findings from the AHS in the published literature were fully considered,” he explained.

    Though glyphosate was developed by Monsanto, it is off-patent and sold by many agriculture companies as one of the most widely used herbicides in the world.

    Glyphosate came to market in 1974, sold under Monsanto’s Roundup label for control of perennial and annual weeds in non-crop and industrial areas. Agricultural crops genetically engineered to withstand glyphosate have greatly expanded the use of the chemistry since 1996. Glyphosate is also used in forestry, urban, and lawn and garden applications.


    Blair told DTN about the process the international body follows.

    To be considered in an IARC review, he said data must come from published studies or studies accepted for publication in the scientific literature.

    “This rule was followed for the glyphosate monograph, also,” Blair said.

    “There are sound scientific reasons for this standard. Ongoing analyses of data mean that even the authors of the work do not consider the work final. When they do, it is submitted for publication. Surely any review body would want the assurance that the authors consider the paper complete.”

    When it comes to unpublished information, he told DTN it has not received a peer review by independent scientists. Such a review provides “an additional level of quality control and indicates that a group of independent scientists consider this work complete and worthy of publication,” Blair said.

    “There are standard procedures for searching the published literature to identify relevant work, but no such procedures exist for uncovering unpublished data. Thus, identification of unpublished data could be incomplete and biased.”

    He said the IARC’s rule of reviewing only published or papers about to be published, “allows selection of studies for review that is independent of study findings, i.e., it applies to both positive and negative studies.”

    Published papers provide what Blair said is a full description of the analyses and their conclusions. These are often not available for pieces of information that might be available from unpublished work.

    “This lack of completeness may introduce faulty assumptions into any review process,” Blair told DTN.

    Gowdy, in his letter, said the IARC decision to withhold the unpublished data raises a number of questions.

    “Dr. Blair subsequently led IARC’s review of glyphosate, which did not consider the AHS finding on glyphosate allegedly because they were unpublished.”


    In March, a scientific panel reviewing the herbicide glyphosate for cancer connections issued a final report of a U.S. Environmental Protection Agency panel that concluded there is “no reliable evidence of an association between glyphosate exposure and any solid tumor, or between glyphosate exposure and leukemia or Hodgkin’s lymphoma.”

    The oversight committee has been asking the NIH for information about its relationship with the IARC for the past two years.

    The committee began asking questions about the funding arrangement between the NIH and IARC in letters to the NIH on Sept. 26, 2016, and Jan. 12, 2017.

    In the letter this week, Gowdy said the House committee is “concerned about these new revelations, especially given Dr. Blair’s apparent admission that the AHS study was ‘powerful,’ and would alter IARC’s analysis of glyphosate.”

    The committee asked for a briefing with the NIH by Aug. 22, as well as documents and communications referring or relating to the decision whether to publish the AHS findings on glyphosate, and all documents and communications to or from Blair related to the AHS findings on glyphosate.

    In March, the European Chemicals Agency, or ECHA, concluded that glyphosate is not carcinogenic.

    In September 2016, EPA posted to its website the issue paper titled, “Glyphosate Issue Paper: Evaluation of Carcinogenic Potential,” a 227-page document outlining the voluminous studies examined by EPA.

    In May 2016, EPA posted and then removed from its website a final report from the agency’s Cancer Assessment Review Committee, or CARC, that essentially cleared glyphosate. The agency said the report was posted inadvertently, but it caused further political and public-relations problems for the agency.

    Todd Neeley can be reached at

    Follow him on Twitter @toddneeleyDTN

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