Fluoride Action Network

Harvard/Bone Cancer Files

The documents that sparked national headlines and a year-long investigation into scientific misconduct by the Harvard dental professor who led NIH's ongoing study of fluoride and bone cancer. Plus, new documents obtained from under the Freedom of Information Act.


In 2005, the National Institute of Health (NIH) began an investigation into scientific misconduct at Harvard Dental School regarding an ongoing NIH-funded study on fluoride and osteosarcoma. The NIH launched the investigation following a request from the Environmental Working Group, which based its request on documents unearthed by FAN researcher Michael Connett. The documents suggested that Dr. Chester Douglass, a Colgate-affiliated advocate of water fluoridation who was also the principal investigator of Harvard study, misrepresented the results of his PhD student’s findings in a written submission to the National Research Council (NRC). At the time of Douglass’s submission, the NRC was reviewing current science on the safety of fluoride in drinking water.

The Misrepresentation:

In his submission to the NRC, Douglass stated that the retrospective component of his national case-control study found no significant association between fluoridated water and osteosarcoma. Just three years earlier, however, Douglass’s PhD student, Elise Bassin, completed a doctoral dissertation which concluded that the retrospective dataset showed a “statistically significant and remarkably robust” relationship between exposure to fluoridated water and osteosarcoma in boys. Although Douglass referenced Bassin’s study in his NRC submission, he never disclosed her findings or the fact that they directly contradicted his claim that the retrospective analysis found  no significant effect.

The Ethics Complaint:

After the Environmental Working Group obtained these documents from FAN, its Senior Vice President, Richard Wiles, and Senior Scientist, Timothy Kropp, wrote a letter to Douglass asking for an explanation.  In the letter, Wiles and Kropp asked:

“why, in your final report to NIEHS, [did] you reference Bassin in support of your conclusion that there is no evidence of an association between fluoride and osteosarcoma, when her doctoral dissertation, on which you were the lead advisor, found perhaps the strongest association between fluoride and osteosarcoma that has ever been measured?”

Douglass never responded to EWG’s letter. EWG thereupon filed a formal ethics complaint with the NIH. In its complaint, EWG stated:

“The principle issue of concern is the serious contradiction between the conclusion in the grant report, where Dr. Douglass reports no evidence of a link between fluoride and osteosarcoma, and the findings of the grant-supported publications listed in support of this position that conclude exactly the opposite. By reporting the results of grant-supported publications in this way, it appears that Dr. Douglass may have viotated Sec. 93.103 (b) of federal research rules concerning falsification of data and the reporting of research results.”

The Investigation:

In response to EWG’s complaint, the NIH initiated a formal investigation. As per its policy, however, the NIH farmed out the investigation to Harvard. Douglass, who had previously donated over one million dollars to Harvard’s Dental School, was provided a draft copy of Harvard’s report four months prior to it being finalized. As EWG noted:

“We are not privy to Harvard’s procedural rules for conducting an academic investigation, but it seems unusual for the subject of the investigation to have access to the report before it is finalized.”

In August 2006, Harvard released a brief statement announcing its conclusion that Douglass did not “intentionally omit, misrepresent, or suppress” Bassin’s findings. When asked, “a Harvard University spokesman declined to say whether Douglass unintentionally committed wrongdoing.” Further, the four-paragraph statement did not explain how Harvard reached its conclusion and — despite multiple requests from Harvard alumni — the university refused to release a copy of the the full report.

FOIA Documents: Private vs. Public Statements:

While it remains unclear how Harvard reached its conclusion, FAN has obtained additional documentation through the Freedom of Information Act (FOIA) which demonstrates that Douglass’s concerns about jeopardizing the U.S. water fluoridation program strongly influenced his analyses and public statements. In a 1997 letter, for example, Douglass explained the need to design the prospective study in a way that would allow them to state that fluoride does not cause osteosarcoma. As Douglass noted, “in order to state no association between fluoride and osteosarcoma with an upper bound confidence of the confidence interval below 1.3 we will need over 711 cases depending on exposure definitions.” Douglass, who as early as 1995 was finding associations between lifelong exposure to fluoridated water and osteosarcoma, expressed his team’s concern that:

“Because of the importance of the question at hand, we think the policy implications of reporting that the relative risk may be higher than 1.5 would have consequences for fluoridation health policies.”

True to this concern, Douglass’s three public presentations about the retrospective study (in 1995, 1998, and 2002) never disclosed what he had privately confided to the NIH: that some of his analyses were finding an association between fluoridation and osteosarcoma. Even after Bassin finished her dissertation in 2001, Douglass continued to omit any indication that an association between fluoride and cancer existed in this data. In fact, at a British Fluoridation Society conference in 2002, Douglass stated that the retrospective data suggested a protective effect from fluoridated water. Douglass reported to the pro-fluoridation audience that, “as percent of life lived in communities with F <0.7 ppm increased, the odds ratio of osteosarcoma increased but was not significant for people who live 100% of their lives in fluoridated communities.”

At points, Douglass’s massaging of the retrospective study reached almost absurd dimensions. In 1998, he publicly reported to the American and European Musculoskeletal Tumor Society that the odds ratio of getting osteosarcoma in fluoridated areas was 0.94 (0.57-1.56). Translated, this means that people in fluoridated areas had a 6 percent reduced risk (without statistical significance) of developing osteosarcoma. Yet, when Douglass privately submitted his final report to the NIH in 2004 he cited this same 1998 presentation as having reported a 28 to 50 percent increased risk in fluoridated areas (OR 1.28-1.50). Although Douglass stated that this increased risk was not statistically significant, he failed to explain how it could possibly be consistent with the six percent decrease he publicly reported at the 1998 conference.

Also, in 2006, after Bassin’s study had been published (and Douglass investigated for scientific misconduct), Douglass published a letter stating that: “We are also finding some positive associations between fluoride and osteosarcoma in the overall (not age-specific) analysis of the first set of cases.” This statement would have come as a surprise to those who had read Douglass’s three previous public descriptions of this data, wherein Douglass reported “no relationship” (1995), a reduced odds ratio in areas with > 1 ppm (1998), and an increased odds ratio in areas with < 0.7 ppm (2002).

The Harvard/Bone Cancer Files

back to top