Over the past several decades, a political movement has evolved whose agenda is to end community water fluoridation. Despite decades of data demonstrating safe and effective reductions in dental caries, anti-fluoridation activists continue their efforts globally. Under the banner of concerned citizens, the activists lead with emotionally charged fears (e.g fluoride causes cancer, fluoride is used in rat poison), back their claims with questionable science and follow up with endorsements from like-minded professionals, including some dentists. Not fully understanding the nuances of research, legislators are urged to err on the side of safety and, when faced with organized public pressure, do so. We examine the psychology of anti-fluoride activism and the role social media and the Internet plays in misinforming the public. A call is made for organized dentistry to increase its online presence and advocacy.
Despite the widespread endorsement of mainstream scientific, professional and educational organizations, dentistry and public health advocates may be losing the battle of community water fluoridation (CFW). Fluoridated water and fluoridated salt have been welcomed in Asia and Africa’s rural and remote communities devoid of health and dental providers. Yet while several nations support fluoridation, Germany, Switzerland, Finland, Sweden, Holland, Japan and Israel have reversed their decision to fluoridate their water supplies. Notably, some communities in Canada have also chosen to cease community water fluoridation.
Reversing community water fluoridation is not based on any scientific evidence, but is politically motivated. When pollsters recently asked Americans, “Do you believe the government adds fluoride to our water supply, not only for dental health reasons, but for other more sinister reasons?” 74% said no, but 9% said yes and 17% were unsure. The same poll revealed that 20% believe that vaccines cause autism 1. Devoid of support from mainstream dentistry and allied sciences, the anti-fluoridationists join fellow anti-science advocates such as the anti-vaccination movement in the use of social media campaigns to win public opinion.
A Brief History of Fluoridation
In 1945, Brantford, Ontario became the first city in Canada to fluoridate their water supply. Brantford was paired with Sarnia, Ontario as part of an 11-year fluoridation case study. With a 35% reduction in caries and 63% decline in severity, Brantford community water fluoridation was hailed as a success 2.
However, fluoridation had its opponents from the beginning. There was significant research conducted to determine if the claims of harm from CWF were true. A pivotal study in the history of water borne fluoride by Leone et al 3 and a study by Phipps and Burt 4 found that the only significant clinical effects from naturally fluoridated water at high levels was fluorosis, a cosmetic problem. They compared towns with 8ppm fluoride to .4 ppm in the Leone study and 3.5 ppm to .7 ppm in the Phipps study. It should be noted that these were concentrations of fluoride that were found naturally in the water supplies studied.
A review by the World Health Organization in 1958 concluded that at 1ppm CWF posed no threat to human health 5.
A number of studies have shown that CWF mainly helps children in lower socio-economic families 6,7,8. Israeli epidemiological studies found that children living in fluoridated areas had considerably less dental caries than those receiving un-fluoridated water 9 though within 15 years anti-fluoridation campaigners managed to have fluoridation stopped in that country.
The 2007 Fluoride Expert Panel recommendations to Health Canada included re-setting the optimum level of fluoride to .7 mg/L (ppm) in recognition of other sources of fluoride in the Canadian diet 10. They found no evidence of increased cancers, fractures, or toxicities of any kind. While CWF is still supported, there is growing concern regarding political influences of the anti-fluoridation movement 11.
Relative Toxicity Hijacked
The Oxford English Dictionary defines toxic as “of or caused by poison; poisonous” and poison is defined as “a substance that can destroy life or harm health”. However, in scientific reality these definitions are useless without some reference to the amount of the substance in question. Members of the scientific community know that the measure of relative toxicity is the LD50 or LC50 of a substance. LD50 is the amount of a material, ingested all at once, which causes the death of 50% of a group of test animals 12. This is not general knowledge for the population at large.
The general population may not understand that almost all substances can be toxic. Water toxicity is well known as well as the relative toxicity of most common substances. The LD50 of water is 90 g/kg in rats. Simply stated, if a population of humans drank 8 litres of water all at once, 50% would die. By comparison, the LD50 of botulinium toxin used in cosmetic treatments is .000001 mg/kg, making it one of the most toxic substances known to man.
There is little correlation between the relative toxicity of substances and the alarm they provoke. The best example is botulinium – a substance widely used in cosmetic procedures with which the public and scientific community seem to be quite comfortable.
Fluoride is a naturally occurring substance in the environment. It can be found in vegetables, fruits, and tea. Most natural water sources contain fluoride, sometimes in very significant concentrations.
The anti-fluoride movement has made many claims about the toxicity of fluoride, including implicating it in cancer. They often quote reputable sources but, more often than not, the sources are taken out of context. The authors will introduce two main examples to illustrate how, at 1 ppm, this non-toxic substance has been converted into a toxic one in many people’s minds.
A national anti-fluoridation organization Fluoride Action Network (http://fluoridealert.org) includes on its website the National Research Council’s review re: EPA fluoride study 13 as proof of the link between fluoride and bone fracture. They (a) do not acknowledge that the EPA’s work was concerned with excessive levels of naturally occurring fluoride in some U.S. domestic water supplies, (b) do not acknowledge that the review was a guide for states in removing that excess fluoride from water supplies and (c) do not acknowledge the NRC’s stand supporting optimal water fluoridation.
The Fluoride Action Network website refers to research by Li Y et al 14 and claims that this works demonstrates that fluoride may be associated with higher cardiovascular risk. They fail to point out that the Li et al study was an investigation into whether injecting patients who had coronary artery plaques with fluoride would result in better resolution of these plaques on PET scans. This study had nothing to do with the effect of fluoride on cardiovascular disease. They investigated the use of fluoride as a diagnostic tool.
Claims that fluoride can cause cancer in humans have never been supported by good science. A very definitive case control study was conducted by Gelberg et al 15 and they found no association between fluoride intake and osteosarcoma. Despite the lack of any proof, the fear of cancer is a predominant theme in the anti-fluoridation efforts.
The Psychology of the Anti-fluoridationists
An anti-fluoridation narrative has emerged that is so compelling that a search on Google returns nearly half a million items. The narrative goes something like this: Nefarious elites, ie. organized dentistry, have colluded with public health officials and the government in an effort to advance an agenda that controls and undermines the people. By slow contamination of a community’s water supply, death by fluoride becomes a perfect crime. Known for its carcinogenic properties and effectiveness as a rat killer, increased levels of fluoride in the drinking water will disable and impair the population via blurred eyesight, cancer, coma and death. Increases of fluoride in the water supply elude detection similar to slow release medication.
Anti-fluoride activists assert that CWF is medical treatment that they never consented to. They claim that due process was eclipsed and multiple illnesses have been caused. They claim that the same arguments do not apply to chlorination of water supplies. However, like chlorine, fluoride does not treat any disease. It is added to the water supply to prevent the world’s most prevalent infectious disease, dental caries. Once established, fluoride cannot treat caries. A similar situation occurs with dysentery – once established it cannot be cured with chlorinated water.
With water being such a vital resource, the notion of it being poisoned has always struck a sensitive chord in human history. Well poisoning fantasies pervaded Middle Ages beliefs. Conspiratorial rumours of those responsible often reached tipping points, especially during the bubonic plague. Church, state and social ostracism joined forces, pointing fingers at the Jews. In response, Jewish houses and synagogues were torched and individuals were burned.
This fear of water poisoning cannot be ignored. For instance, the anti-fluoridation proponents do not rail against fluoride in toothpaste. Nations that use fluoridated salts are not met with the same fears as those that fluoridate their water. This is in spite of the fact that they believe that fluoride causes many serious ill effects. It would seem illogical for any lobby group that finds a substance to be a health hazard to not call for policy makers to discontinue its use throughout the environment. In fact the anti-fluoride lobby claims that CWF is no longer necessary because fluoridated toothpaste provides all the necessary decay prevention that society needs. It seems that the problem is the addition of fluoride to the water supply that inspires fear, not fluoride itself.
A recent investigation into pseudoscience found that pseudoscience belief is inherently more interesting and emotionally appealing. “Science…by bowing to the demands of evidence tends to become hard to swallow for laypeople and even scientists themselves…Pseudosciences, on the other hand, by tuning in on comfortable intuitive representations of the world, have an edge in terms of popular acceptance…an intuitive allure” 16. Illogical beliefs, resentment, pseudoscientific data and Internet empowerment have permitted the anti-scientific alienated members of society to voice their illogical beliefs in harmony with like-minded true believers.
Conspiracy theories lie at the base of anti-science activism. More than left or right politics, conspiracy beliefs explained why someone accepted scientific fact or not 17. Conspiracy theories foster a distrust of science but many people are not aware that they are persuaded by them 18. Many anti-fluoridation activists believe that CWF is part of a conspiracy. But this begs two questions. Why would dentists promote CWF when it decreases the demand for their services and hence could reduce their income? How could over 50 worldwide organizations that support CWF be coordinated and motivated to join in this conspiracy? Furthermore, they do not explain how, since the late 1940’s not a single person has leaked any details of this apparent conspiracy.
Marketing the Bias
Mertz and Allukian 19 made the point that the Internet and social media serve as the main sources of information on CWF for the general public. Measured between June of 2011 and 2012, anti-fluoridation website traffic exceeded the traffic of pro-CWF sites by 5-60 fold. Anti-CWF pages emerged 88-100% of the time when terms fluoride or fluoridation were entered into Facebook, 64% on Twitter and 99% on YouTube. Three key terms were repeated: poison, cancer, useless. Given that Facebook and Twitter reach billions of users, the authors concluded that thousands are misinformed daily.
Legitimacy of much of the anti-fluoridationist claims is also strengthened by the use of “research” published in online, impressive sounding journals. When one checks some of these “studies” for citations they are either not cited in any other research papers or the citations are in articles critical of the original “paper”. When one checks some of these journals on eigenFactor.org they are not even listed, let alone rated in importance. Open access journals charge the researcher a fee to publish their work. Unfortunately there are no standards of quality for these types of journals 20, 21.
It is known that changing opinions is much more difficult when others that are like-minded are around or when politics is involved. However, when one is not threatened and feels safe, he or she is more open to change.
National Public Radio social science correspondent Shankar Vedantam, author of The Hidden Brain (Spiegel & Grau, 2010) offers his relationship with his daughter as a metaphor for change 22. From a recent interview on speaking to parents who are resisting their children’s measles vaccine he says, “The way to go is actually to build trust. You know…..when my child has a nightmare, I don’t come to her in the middle of the night and say, look, you’re a moron for believing there’s a monster under your bed. I acknowledge that the fear might be real, even if there is no monster under the bed. So we know for sure that the parents who aren’t vaccinating their kids are afraid. So the place to start is to acknowledge that the fear is real and to deal with it.”
With fluoridation the fear for some is also real. The disasters of man-made substances like Thalidomide, PCB’s, DDT and others have made many people suspect of all chemicals. Therefore the supporters of CWF must remind the public and policy makers that the science of naturally occurring substances is very different from that of man-made ones. We have evolved with naturally occurring substances for thousands of years. We know what their effects are and at what doses because we can simply look at actual human subjects constantly exposed to fluoride, arsenic, formaldehyde, botulinium etc.
The dental profession must always be prepared to fund and publish high-quality studies to investigate legitimate concerns about fluoridation safety. They should train allied professionals in counter-arguments and greatly expand their influence on the Internet. The public will increasingly receive most of their “scientific” information from the Internet. The dental profession should become extremely effective in capturing the online audience in order to spread scientific fact. The utilization of very skilled advertising and public relations firms that are expert in the use of the Internet and the media is necessary to defend CWF. Their goal should be achieving top ranking on Internet searches when a member of the public enters the word “fluoride” or “fluoridation”. These pages should not only point out the benefits of CWF but they must discredit the pseudoscientific claims made by the anti-CWF activists.
The dental profession as a whole should become more politically savvy, taking strides to increase their influence with policy makers, politicians and public health officials. The profession must be prepared to discredit, in political hearings, the pseudo-science of the anti-fluoride spokespersons. All their arguments against fluoridation can be easily found on their websites and good scientific evidence must be collected to discredit each fallacious claim as it appears and in advance of any public hearing. The presentation of this science must be made understandable to the lay public.
The supporters of CWF may need to constantly remind policy makers of sociologist turned senator Daniel Patrick Moynihan’s quip, “Everyone is entitled to their own opinion, but not their own facts”.
The authors wish to thank Vincent Duronio, PhD, Professor, University of British Columbia Medical School and Director, Experimental Medicine Graduate Program for the review and final editing of this paper.
1. Public Policy Polling. National conspiracy theories. www.publicpolicypolling.com/pdf/2011/PPP_Release_National_ConspiracyTheories_040213.pdf
2. Rabb-Waytowich D. Water fluoridation in Canada: past and present. www.cda-adc.ca/jcda/vol-75/issue-6/451.html.
3. Leone NC, Shimkin MB, Arnold FA, Stevenson CA, Zimmerman ER, Geiser PA. Medical aspects of excessive fluoride in a water supply. Public Health Rep. 1954; 69: 925-36.
4. Phipps KR, Burt BA. Water borne fluoride and cortical bone mass: a comparison of two communities. J Dent Res. 1990; 69(6):1256-60.
5. World Health Organization. Fluoride and oral health: First report of the expert committee on water fluoridation. Technical report series No. 146, 1958.
6. Carmichael CL, Rugg-Gunn AJ, Ferrel RS. The relationship between fluoridation, social class and caries experience in 5 year old children in Newcastle and Northumberland in 1987. British Dent J. 1989;167(1):36-38.
7. Evan DJ, Rugg-Gunn AJ, Tabari ED, Butler T. The effect of fluoridation and social class on caries experience in 5 year old Newcastle children in 1994 compared with results over the previous 18 years. Comm Dent Health. 1996; 13(1):5-10.
8. Riley JC, Lennon MA, Ellwood RD. The effect of water fluoridation and social inequalities on dental caries in 5 year old children. Int J Epidem. 1999; 28(2):300-305.
9. Kelman AM. Fluoridation – the Israeli experience. Comm Dent Health. 1996; 13 Suppl 2:42-6.
10. Health Canada. Findings and recommendations of the fluoride expert panel 2007. http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/2008-fluoride-fluorure/index-eng.php
11. Quinonez CR, Locker D. Public opinions on community water fluoridation. Can J Public Health. 2009; 100(2):96-100.
12. Canadian Center for Occupational Health and Safety. What is a LD50 and LC50? http://www.ccohs.ca/oshanswers/chemicals/ld50.html
13. National Research Council, Committee on Fluoride in Drinking Water. Fluoride in drinking water: A scientific review of EPA’s standards. 2006. http://www.nap.edu/openbook.php?record_id=11571&pages=R1
14. Li Y, Berenji GR, Shaba WF, Tafti B, Yevdayev E, Dadparvar S. Association of vascular fluoride uptake with vascular calcification and coronary artery disease. Nucl Med Commun. 2012; 33(1):14-20.
15. Gelberg KH, Fitzgerald EF, Hwang SA, Dubrow R. Fluoride exposure and childhood osteosarcoma: a case control study. Am J Public Health. 1995; 85(12):1678-1683.
16. Boudry M, Blanke S, Pigliucci M. What makes weird beliefs thrive? The epidemiology of pseudoscience. Philosophical Psychology. 2014. http://philpapers.org/archive/BOUWMW.pdf L
17. Lewandowsky S, Gignac GE, Oberauer K. The role of conspiracist ideation and world views in predicting rejection of science. PLOS One. 2013. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0075637
18. Wood MJ, Douglas KM, Sutton RM. Dead and alive: Beliefs in contradictory conspiratory theories. Social Psych & Personality Sc. 2012; 3(6):767-773.
19. Mertz A, Allukian M. Community water fluoridation on the Internet and social media. J Mass Dent Soc. 2014; 63(2):32-6.
20. Enserink M. As open access explodes, how to tell the good from the bad and the ugly. Science. 2012; 338(6110):1018.
21. Rabesanratana T. The seer of science publishing. Science. 2013; 349(6154):66-7.
22. Vadantam S. The psychology behind why some kids go unvaccinated. 2015. www.npr.org/2015/02/04/383724467/the-psychology-behind-why-some-kids-go-unvaccinated
About the Author
Dr. Pasquale Duronio is a general dentist practicing in Lion’s Head, Ontario.
Dr. Steven Baum is a clinical psychologist practicing in Albuquerque, New Mexico and is the editor of the Journal for the Study of Antisemitism (www.jsantisemitism.org).
The authors report no conflicts of interest nor have they received any financial support from any source.