International Group of Fluoridation Experts
September 21, 2020
Mr. Paul Tsaparis
Chair, York University Board of Governors
1050 Kaneff Tower, Keele Street
Toronto, ON Canada M3J 1P3
c/o Pascal Robichaud
Secretary, Executive Committee
Dear Mr. Tsaparis and Members of the Board of York University, Toronto, Canada,
As governors of York University, you are entrusted with managing potential risk to the reputation of the University.
Therefore, we call upon you to establish an independent international committee to evaluate the quality of academic research which has engendered significant concern about public health in communities in Canada and the United States. We refer to the work of Associate Professor Dr. Christine Till, who has co-authored many papers, including with York University students, purporting to find that community water fluoridation is associated with significant harm.
The public health and scientific communities have already forcefully critiqued at least two of Dr. Till’s studies (please see Appendix One). Nevertheless, Dr. Till’s work continues to have sway in the political and public decision making process because it asserts a “possibility” that water fluoridation is dangerous, however dubious the work’s methodology and conclusions.
That “possibility” frightens some elected officials and administrators. We are advised that several United States boards, which oversee water quality, are currently deciding whether to cease community water fluoridation because of concerns advanced by Dr. Till, her students and associates, including that fluoride harms the developing brain. This “possibility” also featured in debate about fluoridation reinstatement in Calgary, Alberta, Canada in October, 2019.
Dr. Till’s fluoride research conclusions diverge significantly from current research on the safety of community water fluoridation (CWF). Numerous national reviews have found that fluoridation has an acceptable safety profile (such as Australia, 2017; Ireland, 2018; and Canada, 2019). Indeed, the recent Canadian review concluded:
“There is consistent evidence that CWF protects against dental caries [decay] in children and adults and leads to improved oral health outcomes with very uncommon and minor side effects, and that CWF programs are cost saving from a societal perspective.” [emphasis added]
More recently, a German Senate Commission on Food Safety review (Guth et al., 2020) concluded that:
“based on the totality of currently available scientific evidence [which explicitly includes Dr. Till’s maternal fluoride study], the present review does not support the presumption that fluoride should be assessed as a human developmental neurotoxicant at the current exposure levels in Europe.”
Moreover, scientists have been unable to attempt to replicate Dr. Till’s 2019 maternal fluoride study. Repeated requests to Dr. Till, to her funder, the United States National Institute of Environment Health Sciences and to the data repository, Maternal-Infant Research on Environmental Chemicals have not been met with a complete data set.
We understand that some Canadian professors have brought similar concerns to the York University Board of Governors, and note that the Board delegated the matter to the York University President, who dismissed the concerns as a matter of academic freedom. We agree with the Canadian professors’ concerns. We disagree that the question is whether Dr. Till has academic freedom to publish her fluoride work. Dr. Till has exercised such freedom. The question is whether ideology is being misrepresented as science, affecting public health and harming the reputation of York University. Similar concerns were expressed about Andrew Wakefield’s publication that purported to find an association between the measles, mumps and rubella vaccine and autism. A high volume of criticism about Dr. Till’s fluoride work and the noted expertise of the critics make the nature of Dr. Till’s fluoride publications a serious question for York University’s Board to help resolve.
Fluoride research has great significance to public health in many nations. Dental decay is the most common chronic disease of childhood. Untreated dental decay prevents children from eating, sleeping, playing, concentrating and learning and so can delay brain development. Untreated dental decay has led to death in the United States. Community water fluoridation (CWF) reduces dental decay by approximately 25%.
For these reasons, we call upon York University to establish an international, independent committee to determine whether the published work of Dr. Christine Till on the subject of fluoride meets the international criteria by which publications are known as “science”. An international, expert, arms-length committee should review all Dr. Christine Till’s published research reports related to fluoride and fluoridation to determine whether these reports:
- properly review the existing literature;
- rely upon articles only from credible journals;
- use sound, internationally accepted research methods;
- use sound, internationally accepted statistical methods;
- make conclusions based on the data; and
- receive peer review by arm’s length and objective expert reviewers.
Numerous publications by Dr. Christine Till report Dr. Gideon Koren as a co-author. While some of Dr. Koren’s articles were subject to scrutiny, these are not related to fluoride. We do not propose that the articles Dr. Till co-authored with Dr. Koren (and others) be subject to the scrutiny of the committee.
We further request that this committee of international independent experts examine the public and media statements (please see Appendix Two) made by Dr. Till about her publications to determine whether:
- Till’s public comments on her publications and the video she co-produced fairly report the studies’ outcomes;
- Her public health recommendations are appropriate and consistent with her study findings; and
- Her public statements are characterized by truthfulness.
If the video is determined not to represent fairly Dr. Till’s research reports, then we call upon York University to conduct a forensic audit to determine whether the video was financed with public funds entrusted to the oversight of York University for scholarly research and reliable research dissemination, and if so, to require that Dr. Till repay such funds.
This investigation is urgent because the first wave of pandemic restrictions limited people’s access to routine preventive dental care, including dental hygiene and in-school dental screening; a second wave could well do the same. Moreover, pandemic-induced unemployment has caused many people to lose their employment-based dental health coverage. Consequently, the oral health of people in many countries depends more than usual on the preventive health measure of fluoridation, which dubious York University-associated publications are putting at risk.
Given that York University does not have schools of dentistry, medicine or nursing, we recommend that the international experts be chosen by the Royal Society of Canada, in collaboration with similar societies in other countries that offer the benefit of water fluoridation: the United States (the National Academies of Science, Engineering, and Medicine), United Kingdom (The Royal Society) and Australia (Australian Academy of Science). The committee should include experts in statistics, epidemiology and research ethics, as well as public health, toxicology, dentistry, medicine, psychology and nursing.
The committee’s members’ names and email address ought to be published so that documents might be sent directly to the committee by interested parties by a determined date (perhaps by October 15, 2020). The outcome of the review must be made public in whole on the York University website within five working days of its receipt by the York University Board (it is hoped by December 15, 2020). Time is of the essence.
Science advances when researchers follow the rules and prudential customs of science. Whether Dr. Till has done so is the essential question which we ask you to help resolve through the transparent process we have outlined above. We appreciate that this letter comes during a pandemic that strains all institutions’ resources and, therefore, regret that our request comes at this time. Nevertheless, we note that dental decay is likely to affect many more children and adults around the world than COVID-19.
We look forward to hearing from you at your earliest convenience.
Thank you for your attention to this matter, which is having a significant effect on public health.
Michael Lennon OBE, MDS, DPD, FDSRCS(Ed),. FFPH.
Cheshire SK12 2LL, England
John F Beal MBE, PhD, BDS, MFDS, MFPH(Hon), FRSPH
Hon Senior Lecturer, University of Leeds, England
Myron Allukian Jr. DDS MPH
American Public Health Association
Boston, Massachusetts, USA
Scott L. Tomar, DMD, DrPH
Professor and Associate Dean for Prevention and Public Health Sciences
UIC College of Dentistry
801 S. Paulina Street
Chicago, IL 60612, USA
Michael Foley BDSc MPH MEpi
Director, Research and Advocacy
Metro North Oral Health Services
Royal Brisbane and Women’s Hospital
Herston Qld 4029, Australia
Josefine Ortiz Wolfe, PhD, RDH, CHES
Chair-Elect, Oral Health Section
American Public Health Association
Mairead Harding, BDS, MFGDP (UK), MDPH, PhD, FDS
Senior Lecturer in Dental Public Health
Oral Health Services Research Centre,
University College, Cork, Ireland
Sergio Uribe, DDS, PhD
Associate Professor, School of Dentistry
Universidad Austral de Chile, Valdivia, Chile
Visiting Associate Professor,
Faculty of Dentistry,
Riga Stradins University, Riga, Latvia
Alice M. Horowitz, PhD, MA, RDH
Research Associate Professor
School of Public Health
University of Maryland
College Park, MD 20742 USA
Ken Perrott, PhD
Science Advisor, MSOF
Hamilton, New Zealand
Thomas W. Hennessy, MD, MPH
Captain, United State Public Health Service (retired)
Denice Curtis, DDS, MPH, DHS
Master of Public Health Program
Usha Kundu, MD
College of Health
University of West Florida
11000 University Parkway
Pensacola, Fl. 32514, USA
Jennifer Meyer PhD, MPH, CPH, RN
College of Health
Division of Population Health Sciences
Anchorage, AK 99508, USA
Ruby L. Fried, PhD
Assistant Professor of Health Science
University of Alaska Anchorage
Institute for Circumpolar Health Studies (uaa.alaska.edu/ichs), USA
Appendix One: Expressions of Concern about Dr. Till’s Maternal Fluoride Paper
Appendix Two: Dr. Till’s Public Commentary on her Published Reports
Appendix Three: Dr. Christine Till’s Research Reports Related to Fluoride or Fluoridation
Brian Deer, London, England
The Sunday Times
Shaun Lintern, London England
Fergus Walsh, London England
Andrew Gregory, London, England
The Times of London
Denis Campbell, London England
Guardian and Observer
Paul Cullen, Dublin Ireland
Dr. Norman Swan, Sydney, Australia
Health Report, ABC Radio National, Australia
The Age, Melbourne Australia
Amy Corderoy, Sydney Australia
The Sydney Morning Herald
Salma Khalik, Singapore
The Straights Times
New York Times
Los Angeles Times
Jim Fredricks, Editor and Publisher
The Arizona Republic
The Philadelphia Inquirer
Managing Editor News
San Antonio Express News
The Miami Herald
The Boston Globe
Wisconsin State Journal
Green Bay Press Gazette
Avis Favaro, Toronto Canada
CTV National News
Bob McDonald, Toronto, Canada
Quirks and Quarks, Canadian Broadcasting Corporation
CBC Toronto, Canada
Tom Blackwell, Toronto Canada
National Post Newspaper
Rachel Mendleson, Toronto, Canada
André Picard, Montreal, Canada
Globe and Mail Newspaper, Toronto, Canada
Carly Weeks, Toronto, Canada
Globe and Mail, Newspaper, Toronto, Canada
Bill Graveland, Edmonton, Canada
The Canadian Press
- Expressions of Concern regarding Dr. Till’s Attention Deficit Hyperactivity (ADHD) Paper
In 2015, Dr. Till co-authored a paper in Environmental Health purporting to find an association between fluoride and Attention Deficit Hyperactivity disorder (ADHD).
That paper was critiqued by Dr. Ken Perrot in a detailed opinion paper published in the British Dental Journal, and concluded,
“The ADHD-fluoridation study suffers from insufficient consideration of possible risk-modifying factors but has been widely cited because its reported findings appear advantageous to political campaigns against community water fluoridation.”
- Expressions of Concern about Dr. Till’s Maternal Fluoride Paper
Organizations and individuals have issued detailed negative criticism of Dr. Till’s maternal fluoride paper (that purports to find an association between a pregnant woman’s exposure to fluoride and the resulting baby’s IQ at age 3 years).
Concerns about the paper’s literature review, methods, and conclusion are raised by the organizations and persons, such as:
- The Canadian Agency on Drugs and Technology in Health (CADTH)
“The study by Green et al., 2019 concluded that “maternal exposure to higher levels of fluoride during pregnancy was associated with lower IQ scores in children aged 3 to 4 years.” This conclusion was not supported by the data.”
- In the face of CADTH’s October 2019 conclusions, Dr. Till did not request a retraction of her cognition article published in JAMA Pediatrics. Indeed, she appeared to double down on the discredited ‘results’. In July 2020, she wrote to a committee of the City of Green Bay, Wisconsin: “We found that higher levels of fluoride in pregnant women and their drinking water were associated with a 3-to 5-point lower IQ score in their preschool aged children. I am writing to clarify that my co-authors and I have recommended reducing fluoride intake during pregnancy.”
- National Academies of Sciences, Engineering, and Medicine 2020. Review of the Draft NTP Monograph: Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects. Washington, DC: The National Academies Press. https://doi.org/10.17226/25715.
- The committee is concerned that the studies included in the systematic review did not undergo a rigorous statistical review […] The committee finds that approach insufficient inasmuch as some of the studies identified as having low risk of bias did not adequately account for the hierarchical structure of their data, and this compromised their internal validity […] As another example, Green et al. (2019) accounted for community-level effects by adjusting for city in their analysis, but it was unclear how this was done. If they treated city as a random effect, their analytic methods were appropriate. However, if they treated city as a fixed effect, their exposure-effect estimates might be biased. When exposure levels are determined at the group (such as city) level, fixed effect models do not properly separate exposure effects from group effects, and this results in biased estimates and inflated type I errors (Zucker 1990). Although Green et al. (2019) used individual-level exposure rather than city-level exposure, the fixed-effect model could still produce biased estimates if the exposure levels within a city are highly correlated; this might be expected given that some cities were fully on fluoridated water and others were not. Those analytic issues could have been identified by NTP if statisticians had played a more active role in the development of risk-of-bias instructions or its assessment. [Emphasis added].
- 30 International Scientists
- In a letter to the National Institute for Environmental Health Sciences, October 2019, the scientists itemize the specific flaws in Dr. Till’s maternal fluoride paper. Till and her co-authors have not, to date, addressed the majority of concerns raised by the 30 scientists.
- Michael Lennon, OBE, Commentary, IQ Research Discredited, British Dental Journal, volume 229, page75(2020)
- Ken Perrott, retired research scientist in analytical chemistry, environmental chemistry and soil science: AgResearch. Commentary:
- Polishing data and ignoring non-significant relationships
- Anti-fluoridation propaganda now relies on only four studies. 6: Incestuous relationship of these studies
- Thomas Baugley, Professor of Experimental Psychology, Nottingham Trent University UK;
Dr. Oliver Jones, Associate Professor of Analytical Chemistry, Royal Melbourne Institute of Technology (RMIT) University, Australia;
Dr. Joy Leahy, Statistical Ambassador, Royal Statistical Society, UK; Prof Alastair Hay, Professor (Emeritus) of Environmental Toxicology, University of Leeds UK;
Dr. Rick Cooper, Professor of Cognitive Science, Birkbeck, University of London;
Professor Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, UK;
Dr. Stuart Ritchie, Lecturer, Institute of Psychiatry Psychology & Neuroscience, King’s College London;
Professor Grainne McAlonan, Professor of Translational Neuroscience, Sackler Centre for Translational Neurodevelopment, King’s College London, Commentary:
- Steven Novella, academic clinical neurologist at Yale University School of Medicine, Commentary:
- Perry Wilson, MD, MSCE
- Commentary: Is fluoridated Water affecting our kids Intelligence?
- Rene Najera, Johns Hopkins PhD Public Health, and current History of Vaccines Editor, an Educational Resource maintained by the College of Physicians of Philadelphia, Commentary in three parts:
- The Hijacking of Fluorine 18.998, Part One
- The Hijacking of Fluorine 18.998, Part Two
- The Hijacking of Fluorine 18.998, Part Three
- Commentary by Dr. David Parker, PhD, Professor and Director, Division of Population Health Sciences, University of Alaska Anchorage, College of Health, Member, American College of Epidemiology
- Commentary on Maternal Fluoride Study, September 14, 2020
- Christopher Labos, cardiologist with a degree in epidemiology, Montreal; and Jonathan Jarry, a science communicator with the McGill Office for Science and Society
The discussion of the maternal fluoride paper starts at minute 30:00. The Canadian hosts also seem aware of the biased selection of references sourced from sub par journals. One of the hosts found Till’s comments on Canadian television news as “disquieting”.
Some examples of concern
The persons and organizations listed above, along with others, have raised numerous concerns about the statistical practices in the studies co-authored by Dr. Till. For example, some express concern about an alleged major discrepancy in the way the authors reported the fluoride intake (FI) and Full Scale Intelligence Quotient (FSIQ) regression analysis in the Rivka Green master’s thesis as opposed to the JAMA Pediatrics publication. Rivka Green did not find that fluoride intake was associated with FSIQ whereas Dr. Till et al. in the JAMA Pediatrics publication did. The finding of an association is critical to JAMA Pediatrics publication’s main point of discussion: “This association was supported by converging findings from 2 measures of fluoride exposure during pregnancy.”
Specifically, in the JAMA Pediatrics article, the overall effect result for fluoride intake (FI) is reported in this way: “A 1 mg higher daily intake of fluoride among pregnant women was associated with a 3.66 lower IQ score (95%CI, -7.16 to -0.15; P = ,04) in boys and girls.” Table 2 reported that FI was adjusted for “city, home score, maternal education, race/ethnicity, child sex, and prenatal second-hand smoke exposure.” [emphases added]. Yet in the Green Thesis, the overall effect result for fluoride intake is reported as: “With city in the model, FI just missed significance (B = -3.82, 95% CI: -7.65 to 0.02, p = .05)” (on page 34). These two model outputs are different. Perhaps the arm’s length reviewers can determine what changed regarding the data between the writing of the Master’s thesis and the writing of the report for JAMA Pediatrics? Did the authors selectively drop observations to obtain the statistically significant result? How many times did the investigators run the analysis?
Similarly, researchers also question why the authors include secondhand smoke as a covariate in the JAMA Pediatrics Fluoride Intake model when there were only 11 pregnant women with secondhand smoke exposure? Is there sufficient evidence to include this covariate? This small number may have added significant instability to the regression model.
The issue of variance was addressed by a team of authors, some of whom also co-authored the JAMA Pediatrics maternal fluoride study. This team led by Mireille Desrochers-Couture used the same data set. They specifically excluded a variable from consideration because, they wrote,
“Additionally, only 2.8% of the mothers were smoking tobacco during their 1st trimester of pregnancy; maternal smoking was therefore excluded as a covariate for lack of variance.”
In addition to the many detailed expressions of concern and questions mentioned above, dental and pediatric professional organizations have written that they have not been persuaded by the Till et al. maternal fluoride JAMA Pediatrics paper.
- The American Dental Association and American Academy of Pediatrics issued statements that the maternal fluoride paper did not affect their community water fluoridation recommendations.
Concern about arm’s length and objective expert reviewers and accompanying editorial
An additional general concern expressed regarding Dr. Till’s work is whether the people who conducted peer review and supportive editorials are independent of Dr. Till.
Dr. Ken Perrott has discussed the issue of independent review in this article: Anti-fluoridation propaganda now relies on only four studies. 6: Incestuous relationship of these studies
Further, we raise the question as to whether the editorial in JAMA Pediatrics that accompanied the maternal fluoride paper was objective. That favourable editorial was authored by David C. Bellinger, who has published many articles previously with Bruce Lanphear (a co-author of the maternal fluoride paper). Dr. Bellinger has also co-authored work with Phillipe Grandjean who is the editor of the journal Environmental Health, which has published several of Dr. Till’s fluoride papers, along with his own; the authors of these papers tend to cite each other.
This interlinking of authors, reviewers and editorial writer is an argument for arm’s length international review.
(Continued, Appendix Two…)
Dr. Till’s Public Commentary on her Published Reports
The prudence expected of scientists requires that they:
- Make public comments that fairly report their studies’ outcomes;
- Their public statements are consistent with their study findings; and
- Their public statements are not characterized by animus.
With respect to Dr. Till’s public commentary on her fluoride papers and point 1 (fair reporting of study outcomes), we draw your attention to a video co-produced by Drs. Till and Lanphear. That video concedes that the papers under discussion in the video concern observational studies and yet the video states that the studies found causal links. The video has been reviewed by Dr. Steve Slott, Communications Officer of the American Fluoridation Society.
Regarding point 2 (whether Dr. Till’s public and media statements are consistent with her findings), we refer you, for example, to the Time Magazine article in which Dr. Till stated that telling pregnant women to reduce their fluoride intake is “a no-brainer.”
Regarding point 3 (whether Dr. Till’s public statements are characterized by truthfulness), we refer to recent correspondence of Dr. Till regarding the work of a Committee of the City of Green Bay Wisconsin, which is considering whether to cease water fluoridation. As evidence for her apparent position that fluoridation is harmful, Dr. Till wrote to the Green Bay Committee a letter dated July 16, 2020. In that letter, Dr. Till cites the National Toxicology Program Draft Review. This NTP draft document was reviewed, as is the customary process, by the National Academy of Sciences, Engineering and Medicine, and rejected. (Please find the National Academy of Sciences, Engineering and Medicine’s media release here and its complete publication, “Peer Review of the NTP Monograph on Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects” here.) The National Toxicology Program Draft was rejected on the grounds that the studies upon which it based its conclusions had numerous flaws and weaknesses, which were ignored by the National Toxicology Program. We assume that Dr. Till knows that the NTP draft report was rejected. Why does Dr. Till rely on it in correspondence to Green Bay elected officials to suggest that fluoridation is harmful?
In addition, Dr. Till wrote to Dr. Johnson, of the American Fluoridation Society, on July 20, 2020 and copied Green Bay City Council members. In that letter, Dr. Till stated, in effect, the NTP Draft Report is unimpeachable, citing as evidence the impeached document. Dr. Till wrote,
“It is correct that the NTP’s conclusion is not definitive. However, “it is unlikely that evaluation of additional neurodevelopmental effects would change the hazard conclusion” (NTP draft monograph, 2019; p. 49).”
In that July 20, 2020 letter, Dr. Till also wrote to Dr. Johnson that “my coauthors and I recommended reducing fluoride intake during pregnancy”. But Dr. Till must be taken to know that this statement is false because she earlier wrote to the Green Bay Committee that her co-authors are not in agreement. On July 16, 2020, Dr. Till wrote to the Green Bay Committee
“Some of my coauthors have recommended this reduction includes fluoridated water because water is the main source of fluoride for people who live in communities with fluoridation; one pointed out the need for more research before making specific recommendations for community water fluoridation. [emphasis added]
Further, we ask the international, expert, arm’s length committee to consider whether Dr. Till is in a possible conflict of interest as between her duty (to collect and to report research data reliably) and her probable interest (which appears to be to cause an end to community water fluoridation).
If the international, arm’s length, expert committee finds that the Lanphear-Till video does not fairly represent Dr. Till’s publications, then it should, as mentioned in the main body of this letter, inquire by forensic audit into whether public funds meant for research or knowledge translation were used to create the video, and, if so, require those funds to be reimbursed.
LIST OF SOME PUBLIC COMMENTARY BY DR. TILL
- The Impact of Fluoride on Brian Development, 6-minute video, 2020, co-produced by Dr. Christine Till.
This short video states that Dr. Till’s research was observational and showed that fluoride “led to IQ deficits in children” and that “IQ scores in their children dropped”. The video includes the following questions and statements:
- “Is it worth losing 3-5 IQ points to prevent one cavity?”
- “If you are pregnant, don’t drink fluoridated water…”
- “…don’t use fluoridated water to make infant formula.”
- CTV News, Higher fluoride levels during pregnancy may be linked with lower IQ scores in kids: study, Jackie Dunham, August 19, 2019 11:05AM EDT
- WebMD, Could Fluoride Be Bad for Baby During Pregnancy? By Dennis Thompson Health Day Reporter MONDAY, Aug. 19, 2019
- Globe and Mail, Experts challenge study suggesting children exposed to higher levels of fluoride in utero may have lower IQ scores, Carly Weeks, Health Reporter, August 19, 2019
(Continued, Appendix Three…)
Dr. Christine Till’s Research Reports Related to Fluoride or Fluoridation
Media and Other Commentary
Green R, Rubenstein J, Popoli R, Capulong R, Till C. Sex-specific neurotoxic effects of early-life exposure to fluoride: A review of the epidemiologic and animal literature. Current Epidemiology Reports. Accepted, 2020.
Till C & Green R. The evolving science of fluoride: When new evidence doesn’t conform with existing beliefs. Pediatric Research. Invited commentary for special issue on Controversies in Pediatrics, published online May 22, 2020.
Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B. (2019). Fluoride exposure from infant formula and child IQ in a Canadian birth cohort, Environmental International, 134, January 2020.
Till C, Green R, Lanphear B. Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada – In Reply. JAMA Pediatrics, published online December 30, 2019.
Riddell J, Malin A, Flora D, McCague H, Till C. Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth. (2019). Environment International, 133 (Part B).
Green R, Lanphear B, Hornung R, Flora D, Martinez-Mier A, Neufeld R, Ayotte P, Muckle G, Till C. (2019). Fluoride exposure during fetal development and intellectual abilities in a Canadian birth cohort, JAMA Pediatrics, 173(10), 940-948.
Till C, Green R, Grundy JG, Hornung R, Neufeld R, Martinez-Mier A, Ayotte P, Muckle G, Lanphear. (2018). Community water fluoridation and urinary fluoride concentrations in a national sample of pregnant women in Canada, Environmental Health Perspectives, 126(10): 107001.
Bashash M, Merchand M, Hu H, Till C, Martinez-Mier AE, Sanchez BN, Basu N, Peterson K, Green R, Schnaas L, Mercado-Garcia A, Hernandez-Avila M, Tellez-Rojo MM. (2018). Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12 years of age in Mexico City. Environmental International, 121(Pt 1):658-666. doi: 10.1016/j.envint.2018.09.017
Malin AJ, Riddell J, McCague H, Till C. (2018). The relationship among urinary fluoride, urinary iodine and serum thyroid stimulating hormone levels among adults living in Canada. Environment International, 121(Pt 1):667-674.
Malin A & Till C. (2015). Exposure to fluoridated water and attention deficit hyperactivity disorder prevalence among children and adolescents in the United States: An ecological association. Environmental Health, 14 (17): 1-10.