FAN’s submission to UK: “Have your say on extending water fluoridation schemes”

Submission to the Department of Health & Social Care consultation for community water fluoridation (CWF)

June 3, 2022

From the Fluoride Action Network
https://fluoridealert-migrate.local/

Submitted by Ellen Connett <ellen@fluoridealert.org> on behalf of the Fluoride Action Network

Reference: Have your say on extending water fluoridation schemes, May 13, 2022, British Dental Journal

Fluoride and the BRAIN

We submit the following in response to the government’s solicitation for “evidence-based” public comments on the Department of Health’s consultation for community water fluoridation (CWF)

The Fluoride Action Network (FAN) is a non-profit advocacy group set up in 2000 to broaden awareness among citizens, scientists, and policymakers on the toxicity of fluoride compounds. It maintains the largest online data base for fluoride toxicity studies at https://fluoridealert-migrate.local/studytracker/

Because there is an encyclopedic amount of information available on fluoride’s toxicity we have chosen to focus on its neurotoxicity for this submission.

In our view, the evidence that fluoride can harm the developing brain revealed in high quality studies makes its deliberate addition to the public drinking water unthinkable. No benefit to teeth from swallowing fluoride (for which the evidence is weak, see the Cochrane Review of 2015, https://www.cochrane.org/CD010856/ORAL_water-fluoridation-prevent-tooth-decay, and for which there are proven alternatives, see the Childsmile program in Scotland, https://fluoridealert-migrate.local/content/childsmile/ and its equivalent in Denmark) could not possibly justify any damage to the brain. Dentists can repair a damaged tooth but no one can repair a damaged brain. Early damage to the developing brain has lifelong consequences.

We urge the Department of Health & Social Care to perform a health risk assessment on the effects of fluoridated water on the pregnant woman, the fetus, and the formula-fed infant, before implementing fluoridation into the U.K. No regulatory agency in any fluoridating country has ever done this. However, as the UK is contemplating expanding fluoridation to the whole country, it is essential that this is done before they embark on this program.

Before we begin, a few facts on fluoride:

• In 2006: Fluoride was identified as an endocrine disruptor in a report by the National Research Council of the National Academies, titled, Fluoride in Drinking Water: A Scientific Review of EPA’s Standards, page 266 at https://nap.nationalacademies.org/read/11571/chapter/10#266
• In 2010: 41% of Americans age 12-15 had dental fluorosis, https://www.cdc.gov/nchs/products/databriefs/db53.htm
• In 2014: Fluoride was identified as a developmental neurotoxicant by Grandjean & Landrigan in their paper titled Neurobehavioural Effects of Developmental Toxicity, https://fluoridealert-migrate.local/studytracker/16387/
• In 2017-2020: In U.S. funded-studies, the fluoride urinary level in pregnant women was an indicator of reduced IQ in their offspring. The fluoride levels of concern are found in the urine of pregnant women living in fluoridated communities.
  — Bashash, 2017, https://ehp.niehs.nih.gov/doi/10.1289/EHP655
  — Green, 2019, https://jamanetwork.com/journals/jamapediatrics/fullarticle/2748634
  — Till, 2020, https://www.sciencedirect.com/science/article/pii/S0160412019326145?via%3Dihub
• In 2020, Till et al. found a large significant lowering of IQ (i.e. up to 9 IQ points) for children who were formula-fed in fluoridated communities in Canada (F level = 0.7 ppm or less) compared to those who were formula-fed in non-fluoridated communities.

An overview of the evidence for fluoride’s neurotoxicity

• The evidence of fluoride’s neurotoxicity in both animal and human studies has been growing since the late 1980s. There have been over 70 human studies, many from areas with endemic dental and skeletal fluorosis (fluoride’s visible damage to both the teeth and bone) that indicate that fluoride lowers IQ in children. However, many of the early studies (1988 -2015), while yielding highly consistent results, had somewhat weak methodologies. See

Appendix A: List of 74 fluoride-IQ studies reporting an association between fluoride exposure and lowered IQ.
Appendix B: list of 9 fluoride-IQ studies that found no effect

2. Since 2017, there has been a dramatic improvement in the quality of the fluoride IQ studies. These include the Mother-Offspring fluoride studies funded mainly by the National Institute of Environmental Health Sciences (NIEHS), which have shown a strong relationship between a pregnant woman’s exposure to fluoride and lowered IQ in her offspring at exposure levels experienced in communities with drinking water fluoridation. See

Appendix C: list of the Mother-Offspring fluoride studies.
Appendix D: list of studies on fluoride’s neurotoxicity funded by U.S. government agencies.

3. The U.S. National Toxicology Program (NTP), which is part of the NIEHS and provides toxicological reviews for other federal agencies, is on the verge of publishing the results of a 5-year systematic review of the neurotoxicity of fluoride. Two drafts in 2019 and 2020 indicate that the preponderance of the studies that they classify as high quality (i.e. low risk of bias) indicate that brain damage occurs at fluoride concentrations used in water fluoridation programs (at 0.7 ppm or less) or close to these levels (i.e. less than 1.5 ppm).

4. FAN is currently part of a lawsuit against the Environmental Protection Agency (EPA), brought under the Toxics Substances and Control Act (TSCA), together with Moms Against Fluoridation and the Food & Water Watch. The lawsuit calls on the EPA to ban the deliberate addition of fluoridating chemicals to the public drinking water because of fluoride’s neurotoxicity at the levels added to CWF projects. The trial was held in June 2020 in Federal Court. The Court has held back its ruling until it received two documents before making its decision:

Table of contents

1. Two FAN initiatives in 2016
2. The Fluoride-IQ studies, 2017 – present
3. The NTP’s systematic review of fluoride’s neurotoxicity (2016-2022)
4. The Pro-fluoridation arguments for ignoring IQ concerns
5. The TSCA lawsuit against the US EPA
6. Fluoridation and ADHD

1. Two FAN initiatives in 2016

1.1. Because of the growing list of Fluoride-IQ studies, and the downplaying of their importance by pro-fluoridation advocates such as the Division of Oral Health at the Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA), FAN embarked on two initiatives in 2016

• We requested the National Toxicology Program (NTP) undertake a systematic review of ALL the studies (animal, human and cellular) pertaining to fluoride’s potential to damage the brain, and
• We petitioned the EPA under provisions in the TSCA law to ban the deliberate addition of fluoridation chemicals to the drinking water supply because it poses an unreasonable risk to the developing brains of children.

1.2. We will be discussing the significant results of these two initiatives below.  Before that we deal with the game changing events that began on Sept 19, 2017.

2. The Fluoride-IQ studies: 2017 – present

2.1. On Sept 19, 2017 the whole debate on water fluoridation changed irrevocably with the publication of the first of three major US government-funded studies (Bashash et al., 2017, https://ehp.niehs.nih.gov/doi/10.1289/EHP655 ). This was published in Environmental Health Perspectives. Subsequently, Green et al., 2019  was published in JAMA Pediatrics, https://jamanetwork.com/journals/jamapediatrics/fullarticle/2748634 and Till et al., 2020, in Environment International, https://www.sciencedirect.com/science/article/pii/S0160412019326145?via%3Dihub )

2.2.  These three very rigorous high-quality US government funded studies were based on individual measurements of both exposure and outcome and also controlled for a large number of confounding variables. Moreover, they were conducted either in fluoridated communities at 0.7 ppm (Green, 2019 and Till, 2020) or in communities with exposures (from other sources) in the same range as fluoridated communities (Bashash, 2017 and 2018).

2.3. Here are more specific details on the Bashash and other studies.

2.4. Bashash, et al. 2017. This was a 12-year, prospective mother-child cohort study. It showed a 4 to 5 point loss of IQ in offspring, associated with maternal fluoride intake, typical of a fluoridated community.

2.5.  The results were startling. 300 mother/baby pairs were followed for 12 years. The mother’s fluoride exposure was measured directly via urinary fluoride level and the paired offspring’s IQ was measured (again individually) at 4 and 6-12 years of age. All the previous criticisms of the 60 or so prior cross-sectional studies, showing lowered IQ associated with fluoride, were addressed in this study.

2.6. Within days of the Bashash study being published the ADA was quoted in a Canadian newspaper as stating that the results were not relevant to water fluoridation in the USA because the study was done in Mexico City and Mexico does not fluoridate its water (it does fluoridate its salt), (National Post, Sept 21, 2017, https://fluoridealert-migrate.local/news/researchers-urge-caution-over-study-linking-fluoride-exposure-in-pregnancy-to-lower-iqs-in-children/ )

2.7.  This ADA commentary misses a key feature of the study: the authors used urrinary fluoride levels to monitor the mother’s exposure to fluoride and these levels give a measure of their total dose to fluoride and is independent of the source of fluoride. Thus, the location of the study (i.e. source of the fluoride) made no difference to the relevance of the findings. The study can be used to compare the findings with any city in the world for which researchers have urinary fluoride levels for pregnant women. This fact was quickly confirmed in a Canadian study.

2.8. Till et al, 2018. This study surveyed the urine fluoride levels in pregnant women across Canada. They found that the urine fluoride levels were twice as high in fluoridated communities as in non-fluoridated communities. They also found that the average levels in the fluoridated communities in Canada were almost identical to the levels found in the Mexico City study by Bashash, i.e. 0.91 versus 0.87 ppm.

2.9. Green et al., 2019. This study was funded by both the NIEHS and Health Canada and published in JAMA Pediatrics one of the most important journals on pediatrics. The authors essentially replicated the Bashash, 2017 findings with one major difference, they found a lowering of IQ in boys associated with maternal fluoride exposure but not in girls. However, using two other ways of assessing maternal fluoride exposure they found IQ lowered in both boys and girls.

2.10.  A 20-minute podcast, https://fluoridealert-migrate.local/fan-tv/jama-pediatrics-podcast-on-fluoride-iq/,  by two of the JAMA Pediatrics editors released at the same time as the article made it clear that they knew how controversial these findings would be so they gave it a more thorough peer review than normal. They also published in the same issue of the journal an editorial explaining this and an article from Dr. David Bellinger, a leading expert on the neurotoxicity of lead, who put the Green study into the historical context of the many other fluoride-IQ studies and the parallels he saw with lead’s neurotoxicity (https://fluoridealert-migrate.local/studytracker/34915/ ).

2.11.  It is important to note that with both the Green, 2019 and Bashash, 2017 studies this was the first time that studies had been done on fluoride exposure during fetal development.  From the results obtained in both studies it became clear that the most sensitive period as far as fluoride impacting brain development is concerned (at least for boys) was during the fetal stage.

2.12.  So while the water fluoridation debate has hitherto been framed as whether or not we should add fluoride to the drinking water, perhaps a better frame would be should we add fluoride to the amniotic fluid of the fetus from its first day of existence!

2.13. Till et al., 2020 showed that early infancy is another very vulnerable period as far as the brain and fluoride is concerned. Till found a large significant lowering of IQ (i.e. up to 9 IQ points) for children who were bottle-fed in fluoridated communities in Canada (F level = 0.7 ppm or less) compared to those who were bottle-fed in non-fluoridated communities.

2.14.  Based on the findings in the Bashash, Green and Till studies the conclusion is that today water fluoridation in the USA is causing a greater overall loss of IQ points to America’s children than any other factor including lead exposure and pre-term birth.

2.15. Let us be very clear about what is being said – and not being said – here.

2.16. We are not saying that atom for atom, or gram for gram, fluoride is more neurotoxic than lead. It is not. Our concern about lead levels and IQ loss is measured in parts per billion and our concerns about fluoride and IQ loss is measured in parts per million.

2.17. What we are saying is that because fluoride is deliberately added to the drinking water of millions of people every day in the USA it is leading to a greater overall loss of IQ points – at the population level – than lead. Meanwhile, the overall exposure to lead is going down. Lead is not being deliberately added to our water and in fact, vigorous steps have been taken for many years to reduce children’s exposure to lead in gasoline, paint and other products as well as efforts to replace lead water pipes.

3. The NTP’s systematic review of fluoride’s neurotoxicity (2016-2022).

3.1. The NTP has published two drafts of its review of fluoride’s neurotoxicity undertaken at FAN’s request (NTP 2019 and 2020 at https://fluoridealert-migrate.local/researchers/the-national-toxicology-program/part-3/ ).

3.2. The NTP’s final report has still not been released as of June 3, 2022. The draft versions have indicated based on our analysis of their findings that of 29 High Quality (i.e. low risk of bias), 27 found a lowering of IQ and only 2 found no effect. Of these 27, 10 were conducted at 0.7 ppm or lower; another 8 conducted between 0.7 and 1.5 ppm and 9 at 1.5 ppm or higher (ISEE-2020 poster, https://fluoridealert-migrate.local/wp-content/uploads/ISEE2020-ePoster-Neurath.pdf ). These results are summarized graphically below:

The top of the half of this figure is the NTP’s summary of the quality (risk of bias) ratings given by the NTP for 29 studies. The color code ranges from green to red, where green represents low risk of bias (i.e. high-quality) and red means high risk of bias (i.e. low-quality). The lower part of the figure has been added by Chris Neurath, FAN’s research director, who has identified the water fluoridation measured in each study (see  ISEE-2020 poster, https://fluoridealert-migrate.local/wp-content/uploads/ISEE2020-ePoster-Neurath.pdf ).

3.3. In other words, the claim by fluoridation promoters (e.g. the ADA and the CDC) that the lowering of IQ only occurs at much higher concentrations than used in artificial fluoridation programs is false.

3.4. Please Note: finding a lowering of IQ at 1.5 ppm offers no adequate margin of safety when you are exposing a large population of children to 0.7 ppm of fluoride in their drinking water. There are two reasons for this a) children drink different amounts of water and b) there is a wide range of sensitivity to any toxic substance among a large population. Typically, regulatory agencies like the EPA would like a margin of safety of 10, in this case 1.5 ppm only offers a margin of safety of 2.

4. The Pro-fluoridation arguments for ignoring IQ concerns.

4.1. In epidemiology it is very seldom that results only go one way. So while it is absolutely clear that the vast majority of the IQ studies have shown a reduction in IQ associated with fluoride exposure, a few have found no effect and one even purports to show fluoride improving IQ. As one would expect those who promote fluoridation have done their best to use these findings to dismiss concerns. There have also been a couple of reviews that have claimed no overall reduction in IQ. We discuss these studies and reviews below.

4.2. Broadbent et al., 2015
https://ajph.aphapublications.org/doi/10.2105/AJPH.2013.301857 . The draft versions of the systematic review by the NTP gave this study a low-quality rating (a high risk of bias).  Even a lay reader of this study would be suspicious that it was biased. It was written by a dental researcher and fluoridation promoter, who makes no secret for his enthusiasm of fluoridation’s benefits and expresses his concerns that communities in the USA and New Zealand are rejecting fluoridation on the basis of citizens concerns on fluoride’s neurotoxicity based on what he claimed are flawed Chinese studies. Bias aside, it is a weak study. It had little power to find a difference in IQ between the children who drank fluoridated water and those who didn’t. There were nearly 1000 children who grew up in a fluoridated area but less than 100 who did not. He decreased the power still further by using exposure only via water and not via tea, toothpaste or via supplements. He also failed to control for several confounding variables, which ironically, he accused the Chinese of failing to do. This included lead exposure even though data on this was available to him on this and the same cohort has been used to study that. Finally, in the context of the recent US-government funded studies he did not consider exposure during fetal and infant development.

4.3. Aggeborn and Öhman (2016).
The Effects of Fluoride In The Drinking Water, https://www.journals.uchicago.edu/doi/10.1086/711915 . This Swedish study (written by two economists not epidemiologists) looks at populations by region in Sweden and uses the surrogate of average drinking water fluoride level (these are natural levels ranging from 0-1 ppm, Sweden is not artificially fluoridated) and then looks at population measurements for cognitive ability and achievement. Unlike the key US-government funded studies it is not based on individual measurements for either exposure or outcome. Moreover, it does not know, or control for, other sources of fluoride. These may be from dentifrices, fluoride tablets, fluoridated salt etc. Perhaps parents in known low fluoride drinking water compensate for this by giving more fluoride therapy. The authors do not (and cannot) know the answers to this.

4.4. Guth et al. 2020,
https://link.springer.com/article/10.1007/s00204-020-02725-2 and 2021, https://link.springer.com/article/10.1007/s00204-021-03072-6 .  In a review authored by so many authors (29) that it looks more like a petition than a review, these authors give more weight to the weak Broadbent study than they do to the Green et al 2019 study. Such a conclusion runs in the face of normal epidemiological standards and suggests some other agenda is operating here. It is not hard to find. Most of the authors are in food science in German institutes and government bodies, many are industry friendly, and Germany fluoridates its salt. It is quite possible that they feel that a finding that fluorides lowers IQ at low doses would trigger stronger regulations on acceptable levels of fluoride in commercial food products.

4.5. Miranda et al., 2021, https://www.nature.com/articles/s41598-021-99688-w .

This a systematic review from Brazilian researchers. It is well known that the quality of such reviews can be limited by the selection criteria for the studies considered. In this case the authors only considered studies of children aged 8-12, which immediately ruled out the most important neurotoxicity studies published to date. Chris Neurath has published a full critique of this review (https://www.qeios.com/read/X3MKH8 ).

4.6. Ibarluzea et al., 2022, https://www.sciencedirect.com/science/article/pii/S0013935121014821?via%3Dihub

 This prospective cohort study from Spain is clearly an outlier. Not only did they not find a loss of IQ in the fluoridated community compared to the non-fluoridated community, they actually found a 15 IQ point benefit for boys in the fluoridated community! How could this be? Chris Neurath, who has studied the community histories of these Spanish towns, believes that the most likely explanation is that the children in the non-fluoridated community had their IQs depressed because it was an industrial area contaminated with both and lead and arsenic. In his view, Ibarluzea et al failed to adequately control for these confounders. He actually communicated his concerns on this matter with the authors when the paper was still in its abstract form, but this only produced an angry response.

4.7. Conclusion. The weight of evidence of many human studies is that fluoride is neurotoxic for the human brain especially during fetal and infant development, and at the levels experienced in artificially fluoridated communities. As such there can be absolutely no justification for continuing the practice of water fluoridation. It should be ended without any further delay.

5. The TSCA lawsuit against the US EPA

5.1. In 2017, the EPA rejected our TSCA petition on scientific grounds which allowed us to take the matter to federal court (Region 9, San Francisco). Our trial was held in June 2020.

5.2. FAN obtained expert testimony from some of the key researchers in the field of neurotoxicity including those who had authored key studies on fluoride discussed above. These included Howard Hu (director of the ELEMENT cohort in Mexico City which was used in the Bashash, 2017 and 2018 studies); Bruce Lanphear, a world-renowned expert on lead’s neurotoxicity and co-author of the Green, 2019 and Till, 2021 studies and Philippe Grandjean, a world-renowned expert on mercury’s neurotoxicity and author of a risk assessment (BMD analysis) on fluoride’s neurotoxicity, https://onlinelibrary.wiley.com/doi/10.1111/risa.13767 .

5.3. EPA uses Exponent, Inc. experts. To our surprise for its experts the EPA lawyers chose not to use scientists from within their own agency, but instead used experts from the firm Exponent, Inc. This firm is notoriously industry-friendly having defended the “safety” of such toxic products and/or contaminants as dioxins, PCBs, PFOS, and Monsanto’s glyphosate.

5.4. A level playing field. The Court is following the science very closely and this trial offers the world a rare opportunity to examine the science of this matter on a level playing field. In this situation the EPA cannot expect any deference based on its regulatory authority. The Court will rule on the scientific merits of our case.

5.5. One important concession made by Exponent’s experts is that the four US government-funded studies (Bashash, 2017, 2018; Green, 2019 and Till, 2020) included as evidence in our case, are the highest quality human studies on fluoride conducted to date.

5.6. The Court has delayed its ruling on this case until it obtains two documents:

• The first document is a Benchmark Dose Analysis (BMD). Grandjean et al., published this in June 2021. The analysis found that a maternal urine fluoride concentration of 0.2mg/L was enough to lower IQ by 1 point.  This level is exceeded 4 to 5 times in pregnant women living in fluoridated communities. Reference: A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children, at https://onlinelibrary.wiley.com/doi/10.1111/risa.13767

• The second document the Court requested was the National Toxicology Program’s (NTP) systematic review of fluoride’s neurotoxicity which they invested a few million dollars and five years to produce two draft systematic reviews, https://fluoridealert-migrate.local/researchers/the-national-toxicology-program/part-3/ . Both draft reviews stated:
  

  “NTP concludes that fluoride is presumed to be
  a cognitive neurodevelopmental hazard to humans.”

5.7. However, because the future of water fluoridation is clearly in the balance, enormous pressure has been put on the NTP to water down its findings.  On February 9, 2021, the NTP stated in a private statement (https://fluoridealert-migrate.local/wp-content/uploads/niehs-ntp.statement.feb-9.2021.ocr_.pdf ) that it would not complete this review, but would instead write “a state of the science” document without any conclusions. The public learned of this after EPA’s lawyers submitted the NTP’s statement into the trial record. The Court is aware of this development but has said it still wants to read whatever NTP produces.

5.8. The trial is still ongoing.

6. Fluoride and ADHD.

6.1. Attention Deficit Hyperactivity Disorder (ADHD) has become one of the most commonly diagnosed childhood behavioral disorders in the USA. Its basic characteristics are inattention, hyperactivity and impulsivity. “ADHD often continues into adolescence and adulthood, which can lead to medication dependency and a lifetime of treatment” (Maddox et al., 2004, http://fluoridealert-migrate.local/wp-content/uploads/maddox-2004.pdf ).

6.2. In early 2015 a study was published by Malin and Till that examined the relationship between exposure to fluoridated water and ADHD prevalence among children and adolescents, ages 4-17, in the United States, https://ehjournal.biomedcentral.com/articles/10.1186/s12940-015-0003-1 .

6.3. The authors found that, the percentage of each state fluoridated as assessed in 1992, “significantly positively predicted state prevalence of ADHD in 2003, 2007 and 2011, even after controlling for socioeconomic status.”

6.4. A multivariate regression analysis showed that after socioeconomic status was controlled each 1% increase in artificial fluoridation prevalence in 1992 was associated with approximately 67,000 to 131,000 additional ADHD diagnoses from 2003 to 2011. Overall state water fluoridation prevalence (not distinguishing between fluoridation types) was also significantly positively correlated with state prevalence of ADHD for all but one year examined.” (Malin & Till, 2015).

6.5. Bashash et al., 2018, using the same ELEMENT mother-child cohort in Mexico City that they used in their IQ study (Bashash et al, 2017) found that as the mothers’ exposure to fluoride increased (as measured in their urine) so did the number of symptoms of ADHD increase in their offspring, https://www.sciencedirect.com/science/article/pii/S0160412018311814

6.6. Riddell, et al. 2019. These authors found a staggering 284% increase in the prevalence of ADHD among adolescents in fluoridated communities in Canada compared d to non-fluoridated communities – https://www.sciencedirect.com/science/article/pii/S0160412019315971?via%3Dihub

References

Connett et al, 2010 (book)
Connett C, Beck J, Micklem S. 2010.  The Case Against Fluoride: How Hazardous Waste Ended Up in Our Drinking Water and the Bad Science and Powerful Politics That Keep It There. Chelsea Green (VT), https://www.chelseagreen.com/product/the-case-against-fluoride/

Grandjean BMD analysis, 2021
Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song PXK, Lanphear B, Budtz-Jørgensen. 2021. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. Risk Analysis, June 8. https://fluoridealert-migrate.local/studytracker/39766/

Neurath – ISEE poster

Neurath C. Connett M.  2020. Fluoride Developmental Neurotoxicity: Dose-Response Analyses of Recent High Quality Studies. Poster for International Society for Environmental Epidemiology conference 2020. http://fluoridealert-migrate.local/wp-content/uploads/neurath-2020-isee-eposter-ver11.pdf

Till 2018
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):107001-13. https://fluoridealert-migrate.local/studytracker/32334/

Bashash 2017
Bashash M, Thomas D, Hu H, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Ettinger AS, Wright R, Zhang Z, Liu Y, Schnaas L, Mercado-García A, Téllez-Rojo MM, Hernández-Avila M. 2017. Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6-12 Years of Age in Mexico. Environmental Health Perspectives, Sept 19;125(9):097017. https://ehp.niehs.nih.gov/doi/10.1289/EHP655

Bashash 2018
Bashash M, Marchand M, Hu H, Till C, Martinez-Mier A, Sanchez BN, Basu N, Peterson KE, 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. Environment International 121(1)658-666. https://www.sciencedirect.com/science/article/pii/S0160412018311814

Bellinger 2012
Bellnger DC. 2012 Comparing the population neurodevelopmental burdens associated with children’s exposures to environmental chemicals and other risk factors.   NeuroToxicology 33(4):641-3. https://www.sciencedirect.com/science/article/abs/pii/S0161813X12000794

Choi 2012
Choi AL, Sun G, Zhang Y, Grandjean P. 2012. Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis. Environmental Health Perspectives, 120:10. https://doi.org/10.1289/ehp.1104912

Cunningham  2021
Cunningham JEA, McCague H, Malin AJ, Flora D, Till C. 2021. Fluoride exposure and duration and quality of sleep in a Canadian population-based sample. Environmental Health 20:16.  https://ehjournal.biomedcentral.com/articles/10.1186/s12940-021-00700-7

Cui 2018
Cui Y, Zhang B, Ma J, Wang Y, Zhao L, Hou C, Yu J, Zhao Y, Zhang Z, Nie J, Gao T, Zhou G, Liu H. 2018. Dopamine receptor D2 gene polymorphism, urine fluoride, and intelligence impairment of children in China: A school-based cross-sectional study. Ecotoxicology and Environmental Safety. 165:270- 277. https://www.sciencedirect.com/science/article/abs/pii/S0147651318308674?via%3Dihub

Green 2019
Green R, Lanphear B, Hornung R, Flora D, Martinez-Mier EA, Neufeld R, Ayotte P, Muckle G, Till C. 2019. Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada. JAMA Pediatrics. August. https://jamanetwork.com/journals/jamapediatrics/fullarticle/2748634

Lanphear, Till and Birnbaum (Op-Ed) 2020. Op-ed: It is time to protect kids’ developing brains from fluoride. Environmental Health News.  Oct 7. https://www.ehn.org/fluoride-and-childrens-health-2648120286.html

Maddox 2004
Maddox, C., & Wilson, K. B. (2004, July). Race matters: Disparities in African American children with attention deficit hyperactivity disorder. Paper presented at the McNair Scholars Conference at Penn State University, State College, PA. http://fluoridealert-migrate.local/wp-content/uploads/maddox-2004.pdf

Malin and Till, 2015
Malin AJ, 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 2015;14:17. https://ehjournal.biomedcentral.com/articles/10.1186/s12940-015-0003-1

Malin 2018
Malin AJ, Riddell J, McCague H, Till C. 2018. Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status. Environment International. Dec;121(Part 1): 667-674.     https://www.sciencedirect.com/science/article/pii/S016041201830833X

HHS 2015
U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries. April 2015. http://fluoridealert-migrate.local/wp-content/uploads/hhs-guidelines.4-27-15.pdf

NRC 2006
NRC (National Research Council of the National Academies). 2006. Fluoride in Drinking Water: A Scientific Review of EPA’s Standards. Washington, DC: The National Academies Press. https://doi.org/10.17226/1157

NTP 2019
National Toxicology Program (NTP). 2019. First Draft NTP Monograph on the Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects. http://fluoridealert-migrate.local/wp-content/uploads/2019.ntp_.draft-fluoride-systematic-review.online-Oct-22.pdf

NTP 2020
National Toxicology Program (NTP). 2020. First Revised Draft Monograph on the Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects. http://fluoridealert-migrate.local/wp-content/uploads/ntp.revised-monograph.9-16-2020.pdf

Riddell 2019
Riddell JK, Malin AJ, Flora D, McCague H, Till C. 2019. Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth.  Environment International. 133 (Part B): 105190. https://www.sciencedirect.com/science/article/pii/S0160412019315971?via%3Dihub

Till 2020
Till C, Green R, Flora D, Hornung R, Martinez-Miller EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B. 2020. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environmental Health Perspectives.

Appendix A

The list of 74 fluoride-IQ studies reporting an association between fluoride exposure and lowered IQ

The 74 human studies listed below report an association of exposure to elevated levels of fluoride and lowered IQ. These studies are based on IQ/cognitive examinations of 27,174 children (71 studies) and 689 adults (3 studies).

Location of the Studies: China (45), India (14), Iran (4), Mexico (4), Canada (2), Egypt (1), Kenya (1), Pakistan (1), Sudan (1), Indonesia (1).

Sources of Fluoride Exposure in the IQ Studies:
• 64 studies: drinking water,
• 9 studies: coal burning,
• 1 study: salt fluoridation (Mexico, Cantoral et al., 2021).

The 74 IQ-Fluoride Studies:

Appendix B

The 9 fluoride-IQ studies finding no association between fluoride and IQ:

Appendix C

The Mother-Offspring Fluoride Studies

There are now 9 Mother-Offspring fluoride studies. Eight of the studies revealed that the fetus and the formula-fed infant (Till 2020) are the most vulnerable to fluoride’s neurotoxicity. Seven of the nine studies measured the urinary levels of pregnant women for fluoride as it is the most accurate indicator of daily total fluoride intake. The urinary fluoride levels taken from the pregnant mothers were compared to the IQ of their offspring (up to 12 years of age) in blinded tests where the examiners were unaware of the subject’s fluoride exposure status at the time of the neurodevelopmental exams.  Certain high levels of fluoride in the pregnant women’s urine were found to significantly impact the IQ, or neurodevelopment, of the offspring. These high urinary fluoride levels are found in pregnant women living in fluoridated cities as well as in naturally-occurring high fluoride areas. The first study on urinary fluoride levels in pregnant women in the U.S. was published in April 2020. The U.S. and Canada have the same “optimum” level for fluoridation schemes: 0.7 mg/L fluoride. Lastly, no government agency has performed a risk assessment on the effects of water fluoridation on the pregnant woman, the fetus, or the bottle-fed infant.

9. Cantoral et al. (2021) reported lower IQ in children at 24 months of age.

This study, Dietary fluoride intake during pregnancy and neurodevelopment in toddlers: a prospective study in the Progress Cohort, included 103 mother-infant pairs. It was performed in Mexico where salt is fluoridated. ‘The practice of adding salt to a meal was reported by 27% of the participants.” According to the authors,

“To our knowledge, this is the first prospective and longitudinal study to examine associations between maternal fluoride intake from food and beverages during pregnancy and offspring neurodevelopment. Our findings are consistent with two other prospective cohort studies from Mexico that measured urinary fluoride levels in pregnancy…

“In the mixed-effects longitudinal model, we observed a statistically significant negative association between dietary fluoride intake in pregnancy and cognitive score (averaged across both time points) in boys, but not girls (interaction p value = 0.07) (Table 4). Specifically, a 0.5 mg increase in dietary fluoride intake during the third trimester and across pregnancy (i.e. trimesters 2 and 3) was associated with a 3.10-point (95% CI: -5.67, -0.53) and 3.46-point (95% CI: -6.23, -0.70) lower cognitive score in boys, respectively…

“In this prospective cohort study, higher exposure to fluoride from food and beverage consumption in pregnancy was associated with reduced cognitive outcome, but not with language and motor outcome in male offspring over the first two years of life. Given the ubiquity of fluoride in food and beverages, it will be important to develop recommendations for how vulnerable populations, such as pregnant women, may limit dietary fluoride intake to minimize potential adverse health risks of the unborn fetus.”

8. Till et al. (2020) reported lower IQ in children at 3 – 4 years of age.

Titled, Fluoride exposure from infant formula and child IQ in a Canadian birth cohort and funded by the U.S. National Institute of Environmental Health Sciences (NIEHS), it was published in Environment International. The authors “examined whether feeding status (breast-fed versus formula-fed) modified the impact of water fluoride and if fluoride exposure during fetal development attenuated this effect.” The mothers urinary fluoride (MUF) levels were used as a proxy of fetal fluoride exposure. A second model estimated the association between fluoride intake from formula and child IQ. According to the authors:

• Consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake.
• Breastfed infants receive very low intake of fluoride.
• We compared IQ scores in 398 children who were formula-fed versus breastfed during infancy.
• IQ scores were lower with higher levels of fluoride in tap water.
• The effect was more pronounced among formula-fed children, especially for nonverbal skills

7. Green et al. (2019) reported lower IQ in children between 3 – 4 years of age.

Titled Association Between Maternal Fluoride ExposureDuring Pregnancy and IQ Scores in Offspring in Canada, and published in JAMA Pediatrics, this study took place in 6 Canadian cities with 512 mother-child pairs. Women living in areas with fluoridated tap water compared with nonfluoridated water had significantly higher mean urinary fluoride concentrations. A 1-mg/L increase in urinary fluoride levels was associated with a 4.49-point lower IQ score in boys, but there was no statistically significant association with IQ scores in girls. A 1-mg higher daily intake of fluoride among pregnant women was associated with a 3.66 lower IQ score in boys and girls. According to the authors, the urinary fluoride levels observed in this study are “typically found in white North American women.” This study was also funded by the U.S. NIEHS.

6. Bashash et al. (2017) reported lower IQ in children at 4 years of age and between 6 to 12 years of age.

This study by Bashash et al., titled Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6–12 Years of Age in Mexico, was published in September 2017 in the prestigious journal Environmental Health Perspectives

The researchers followed up to 299 women-offspring pairs in Mexico during a 12-year period and reported that the fluoride levels in the urine of the pregnant women was the factor for a loss of 5 to 6 IQ points in the offspring at ages 4 and 6-12 years of age. The fluoride levels in the urine of the pregnant women are similar to what is found in adults in fluoridated communities in the U.S. This study, as well as the following one by Thomas et al., was funded by the U.S. National Institutes of Health, the U.S. Environmental Protection Agency, and the U.S. NIEHS.

5. Thomas et al. (2018) reported lower IQ in children between 1 to 3 years of age.

This study by Thomas et al., titled, OPV – 2 Prenatal fluoride exposure and neurobehavior among children 1–3 years of age in Mexico, was presented at a conference on epidemiology in Germany in March 2018. Only the abstract of the study has been published in the journal Occupational & Environmental Medicine. This abstract reports pregnant women’s fluoride exposure is linked to lower IQ in their children at one- to three-years-old at levels commonly found in U.S. women. The authors of this study said that their findings “suggest higher in utero exposure to fluoride has an adverse impact on offspring cognitive development that can be detected earlier, in the first three years of life.”

4. Bashash et al. (2018) on Attention Deficit Hyperactivity Disorder:

This paper, Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6–12 years of age in Mexico City, was also funded by NIEHS. The authors reported:

• Higher concentration of maternal urinary fluoride was associated with more ADHD-like symptoms in school-age children.
• Prenatal exposure to fluoride was most strongly associated with behavioral ratings of inattention, but not hyperactivity and impulse control.
• Findings are consistent with the growing body of evidence suggesting neurotoxicity of early-life exposure to fluoride

3. Valdez Jiménez et al. (2017) reported lower IQ in children between the ages of 3 to 15 months.

This was the first mother-infant pair study performed by a team from three universities in Mexico. The study is titled In utero exposure to fluoride and cognitive development delay in infants by Valdez Jiménez et al. and was published in the journal Neurotoxicology on March 1, 2017. This study differs from the other two studies discussed above inasmuch as the pregnant women in the study lived in areas of high naturally occurring fluoride in the drinking water. The authors noted that “cognitive alterations in children born from exposed mothers to F could start in early prenatal stages of life.”

• this study had 65 mother-baby pairs
  • the IQ testing took place between the ages of 3 to 15 months
  • this study took place in an area with high naturally occurring levels of fluoride in the drinking water (called endemic hydrofluorosis areas).
  • Over 81.5% of the samples of tap water were above 1.5 mg/l with the highest value of 12.5 mg/.
  • 33.8% of the births were pre-term. The authors stated, “We found higher levels of F in urine across trimester in premature compared with full term.”
  • The authors state, “In this study near to 60% of the children consumed contaminated water and the prevalence of children with IQ below 90 points was 25% in the control group (F urine 1.5 mg/g creatinine) in comparison with the 58% of children in the exposed group (F urine >5 mg/g creatinine)… Our data suggests that cognitive alterations in children born from exposed mothers to F could start in early prenatal stages of life.”

2. Li et al. (2004) reported significant differences in the behavioral neurological assessment score in 1 to 3 day-old offspring

This Chinese study, Effects of high fluoride level on neonatal neurobehavioral development, was first published in 2004, translated into English and re-published in 2008 in the journal Fluoride 41(2):165–170.

• Ninety-one full-term, normal neonates were randomly selected for observation, 46 were male and 45 female.
• A urine sample was collected after the pregnant women were hospitalized but before labor began
• The standard neonatal behavioral neurological assessment (NBNA) method was used for measurements, which were carried out by professionals (pediatric department physicians working in neonatal section trained in national NBNA training program)
• In the high fluoride group the urinary fluoride level averaged 3.58±1.47 mg/L, significantly higher than the normal range of 0.18–2.6 mg/L and was significantly different from the fluoride level in urine samples from the control group. When compared with the fluoride result in urine samples from the control group (1.74±0.96 mg/L), the difference is statistically very significant (p<0.01).
• The two study groups are located in the same area with similar climate, living habits, economic and nutritional conditions, and cultural backgrounds. There is no industrial fluoride contamination in the endemic fluoride or the non-endemic control area. As can be seen in Table 1, there was no statistically significant difference in the delivery mode, birth weight, infant length, and sex.
• As seen in Table 2, neonatal neurobehavioural assessment of the neonates from the high fluoride group and the control group indicated that the neurobehavioural capability and agonistic muscle tension from the high fluoride group were impaired, resulting in a statistically significant lower overall (total) assessment score than in the control group (p<0.05).
• Table 3 shows that the various neurobehavioral capabilities, such as non-biological visual, biological visual, and auditory directional reactions of the neonates from the high fluoride group lagged behind those of the control group with differences that are statistically significant (p<0.05).

1. Chang et al. (2017) reported significant differences in the mental development index and psychomotor development index of the offspring at 3, 6, 9, and 12 months of age.

This study,  Analysis on the Effect of Coal-Burning Fluorosis on the Physical Development and Intelligence Development of Newborns Delivered by Pregnant Women with Coal-Burning Fluorosis, was conducted in China and published in the  Chinese Journal of Control of Endemic Diseases 32(8):872-873.

• • 118 newbors in this study: The Observation Group: 68 newborns from coal-burning high-fluoride areas (called endemic fluorosis areas). The Control Group: 50 full-term newborns delivered by healthy pregnant women.
• The type of test used: Mental development index (MDI) and psychomotor development index (PDI) (assessed using the Standardized Scale for the Intelligence Development of Children formulated by the Children Development Center of China [CDCC]).
• The body weight, body length, head circumference, chest circumference, upper arm circumference and top arm length of newborns in the observation group were all significantly lower than those in the control group, and their differences were statistically significant (P < 0.05).
• At 3, 6, 9 and 12 months after birth, the grades of body weight development and body-length development of infants in the control group were significantly higher than those in the observation group (P < 0.05);
• Both the Mental development index and the psychomotor development index of infants in the observation group were significantly lower than those in the control group (P < 0.05).
• The socioeconomic status of all the three villages were the same in both endemic and control areas.
• The results suggest that maternal exposure to high levels of fluoride have a significant impact on the intelligence development of newborns.

What were the fluoride levels that caused the harm?

Urine tests are a better indicator of daily total fluoride intake than is the concentration of fluoride in the drinking water. Testing urine for fluoride provides one of the best indicators for all exposures to fluoride whether its through ingestion of water and food or through inhalation.

The Bashash et al. (2017) study found a very large effect. An increase in urine fluoride of 1 mg/L was associated with a drop in IQ of 5 to 6 points. To put this into perspective with the fluoride levels ingested by the Mexican mothers and the levels ingested in fluoridated parts of the U.S., the average fluoride intake in the Mexican mothers was about the same as that in women in the U.S. It was not substantially higher. The range of fluoride levels in Mexico also corresponded closely to the range found in most of the U.S. The higher levels were similar to what is found in areas in the U.S. with fluoridated water, and the lower levels were similar to what is found in most unfluoridated parts of the U.S.

Most of the Mexican women had urine fluoride between 0.5 and 1.5 mg/L. Studies have found that adults in the U.S. have between about 0.6 and 1.5 mg/L, almost exactly the same range. From the low end of that range to the high end is a difference of 1 mg/L which is what caused the 5 to 6 IQ point difference in the children of the study.

In the latest Green et al. (2019) study, an increase in urine fluoride of 1 mg/L was associated with a drop in IQ of 4.49 points in boys. The authors noted that women living in areas with fluoridated tap water compared with nonfluoridated water had significantly higher mean urinary fluoride levels.

A 2018 national survey of urinary fluoride levels in pregnant women in Canada

This study by Till et al., published on October 11, 2018, found that pregnant women in “optimally” fluoridated Canada have significantly higher levels of fluoride in their urine than women living in non-fluoridated communities. This study also showed that pregnant Canadians had fluoride urinary levels similar to those that reduced IQ in offspring in the study by Bashash et al. (2017). The U.S. NIH-funded Bashash study reported a lowering of 5 to 6 IQ points in the offspring. These findings suggest that the results from Bashash’s Mexico City study may be appliicable to Canada and the U.S. as both countries use 0.7 mg/L fluoride in their fluoridation schemes.

The study: 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.

Appendix D

List of studies on fluoride’s neurotoxicity funded by U.S. government agencies

The U.S. agencies:

NIEHS (National Institute of Environmental Health Sciences) has responsibility for the NTP (National Toxicology Program). The NIEHS is the research arm of U.S. regulatory agencies. The NTP is best known for its Reports on Carcinogens.

NIDCR (National Institute of Dental and Craniofacial Research) is a pro-fluoridation federal agency. It funds the majority of studies on dental research in the U.S.

EPA (Environmental Protection Agency) has responsibility for ensuring “safe” fluoride levels in drinking water. The EPA has never performed a risk assessment on pregnant women, the fetus, or the formula-fed infant living in fluoridated communities. According to the Mother-Offspring fluoride studies, these are the very populations most at risk to fluoride’s neurotoxicity.

CDC (Centers for Disease Control and Prevention). The Division of Oral Health at the CDC is the nation’s promoter of fluoridation. They recently contracted to bring to market a system to fluoridate small communities using ‘sodium fluorosilicate tablets’ which they estimate will allow up to 19 million more Americans to drink fluoridated water.

NOTE: Not all studies funded by U.S. agencies are listed below, but we will attempt to identify all the studies as we find them.

+++