In our new book Fluoride Harm: Suppressed Science and Silenced Voices, I write about Nancy Quirk, the retired General Manager of the Green Bay Water Utility, whose unwavering support for fluoridation was driven more by family pride and institutional ties than by science. Quirk was well-connected locally and nationally, yet her influence helped delay protective actions and perpetuate misinformation about fluoride. In this public comment in DeForest, she weighs in on fluoridation policy—showing how deeply entrenched the old narratives still are. Watch her statement here: https://youtu.be/NCe5VNw-M0A?si=q5Q6y6qopCKMvJKj&t=6480. 

This is my response to DeForest Decision Makers.

Dear DeForest,

At your recent board meeting, Nancy Quirk cited the Antigo, Wisconsin “real-world evidence” as proof that fluoride prevents cavities, claiming that tooth decay surged when Antigo stopped fluoridation in the 1960s and declined when it was reinstated. This narrative gets repeated often, but it relies on outdated, unblinded, and methodologically weak data that is more than 50 years old—data that would never meet modern scientific standards.

I know this history well. Before COVID shut down access, I spent weeks at the Wisconsin Historical Society on State Street in Madison going through boxes of Isabel Jansen’s fluoride archive on Antigo. My 10-year-old son, Ko, would come with me—he’d spread out his Playmobil pirate ship across the big tables, using his hands to build forts and full battle stations while chatting with the staff about history. I’m not an iPad mom; he learned by touching, building, imagining, and engaging with real people in a real place while I sifted through primary documents. And in those archives, it became clear just how politically charged the Antigo story was and how many unanswered questions were erased from the simplified narrative that continues to be repeated today.

To begin with, the Antigo cavity survey was not blinded, and it was conducted by the Wisconsin Division of Health, which was openly campaigning in favor of fluoridation at the time. As dentists will tell you, cavity diagnosis is highly subjective—three dentists can give you three different counts. Without blinding and without standardized diagnostic criteria, it is impossible to know whether the rise in tooth decay reported in the Antigo survey reflected true changes or simply examiner bias from fluoride-promoting evaluators who wanted to see fluoridation restored. This is precisely why unblinded, highly subjective surveys like Antigo’s are not accepted as reliable evidence today.

Yet Nancy continues to lean on this 1960s story as though nothing in science has progressed in the last half-century. Meanwhile, modern research is validating the concerns of the very person who originally challenged fluoridation in Antigo—Registered Nurse Isabel Jansen.

Isabel Jansen worked at Marquette University Medical and Dental Schools as a surgical assistant and was deeply familiar with both medical and dental practice. When Antigo became one of the first fluoridated communities in Wisconsin in 1949, she voiced concerns—supported by public health data—that long-term fluoride ingestion might contribute to heart disease, vascular damage, and other systemic health problems. For this, she was heavily criticized and dismissed. And yet today, her warnings are being confirmed by rigorous, modern scientific studies. Isabel Jansen wrote a book: Fluoridation: A modern Procrustean practice https://www.amazon.com/Fluoridation-Procrustean-practice-Isabel-Jansen/dp/0932298737. 

I attached an article from Grand Rapids, Michigan—the first city in the United States to fluoridate—that raised serious concerns about high disease rates in the community. Heart disease was specifically noted as one of the conditions disproportionately affecting Grand Rapids residents after fluoridation. This is especially important context because it aligns with the early warnings of Isabel Jansen and the patterns now being confirmed by modern cardiovascular research.

The attached article also mentions that $5,000 in federal funds were allocated to study the high death rates in Grand Rapids, MI. Despite years of searching, I have never been able to locate this study, and multiple people have told me that it either does not exist or was never made publicly available. This lack of transparency raises even more questions about what early researchers may have discovered—and why those findings were never shared with the public.

MODERN RESEARCH VALIDATING JANSON’S CONCERNS

• Cardiac Structure & Function in Children (2025 – Mexico)

A study of 374 young children found that fluoride exposure was associated with measurable changes in left ventricular mass and systolic function—structural and functional heart changes that can influence lifelong cardiovascular health. These findings align directly with Jansen’s early warnings about fluoride’s potential cumulative impact on the heart. https://www.sciencedirect.com/science/article/pii/S0013935125011831

• Hypertension & Endothelial Injury (2025 – China)

A detailed study of 724 adults concluded that fluoride exposure is an independent risk factor for hypertension. Mechanistic work shows fluoride damages endothelial cells, triggers arterial inflammation, and contributes to atherosclerosis—exactly the types of cardiovascular pathways Jansen suspected. https://www.sciencedirect.com/science/article/abs/pii/S0013935125003536

• “Vascular Fluorosis”

A 2025 article summarizes decades of vascular research showing how fluoride circulating in blood can harden soft tissue, damage endothelial cells, and impair vascular function—essentially a form of vascular fluorosis. This concept echoes Jansen’s early analysis of public mortality patterns. https://townsendletter.com/vascular-fluorosis/ 

• Animal Study: Fluoride-Induced Cardiac Injury (2025)

Laboratory research confirms fluoride causes vascular endothelial damage, a root cause of cardiovascular disease. Researchers even identified protective compounds (blueberry anthocyanins), highlighting that fluoride’s cardiovascular toxicity is now mechanistically understood. https://www.sciencedirect.com/science/article/abs/pii/S0278691525004338

• Hypertension in Animals (2024)

In vivo and in vitro models demonstrate that fluoride exposure increases blood pressure and causes pathological changes in the aorta—corroborating the human hypertension studies and Jansen’s observations on increased heart-related mortality. https://www.sciencedirect.com/science/article/pii/S0147651324007577

• Stroke Risk (2024 – China)

A large ecological study found that stroke rates are significantly higher in regions with endemic dental fluorosis—and remain elevated even 20 years after fluoride levels were reduced. The U.S. is also an endemic dental fluorosis region, with more than half of teens affected. https://pubmed.ncbi.nlm.nih.gov/39330607/

• Prenatal Fluoride Exposure & Heart-Rate Variability (2023 – MIREC Cohort)

In Canadian infants, prenatal fluoride exposure was associated with lower heart-rate variability, a marker of impaired autonomic nervous system function and lifelong risk for cardiovascular disease. This study also found adverse impacts on early visual acuity—showing fluoride affects multiple biological systems even at low doses. https://www.sciencedirect.com/science/article/pii/S0160412023006098

These modern findings are rigorous, controlled, and conducted with today’s scientific standards—not the biased, unblinded dental tallies of the 1960s.

THE REAL STORY OF ANTIGO

Antigo’s return to fluoridation after five years was not driven by high-quality evidence but by a heavily publicized, unblinded survey carried out by pro-fluoride officials. This was a political campaign—not a scientific demonstration.

Meanwhile, Isabel Jansen’s broader concerns—mocked and ignored for decades—have now been validated by cardiology, toxicology, epidemiology, and developmental science.

Today, fluoridated communities across the U.S. still suffer epidemic tooth decay, especially low-income children—so the claim that fluoridation is an equity enhancer simply hasn’t materialized. Tooth decay remains the #1 most common chronic disease in children in America, despite over 70 years of widespread fluoridation.

SCIENCE HAS ADVANCED. FLUORIDE POLICY HAS NOT.

Nancy Quirk continues to rely on a 50+ year-old unblinded tooth-count survey while ignoring modern cardiovascular, neurological, developmental, and toxicological research. The Antigo story is not “real-world” evidence—it’s outdated political propaganda.

Today’s science is catching up with what Isabel Jansen tried to tell us decades ago: fluoride is not a benign mineral. It is a biologically active compound capable of affecting the heart, blood vessels, developing brain, and autonomic nervous system.

When we discuss public health, we must look at the current evidence, not 1960s anecdotes.

Isabel Jansen was one of the giants that I stand on the shoulders of. I write in our new book Fluoride Harm: Suppressed Science and Silenced Voices https://www.amazon.com/dp/1069802204/. 

Standing on the Shoulders of Giants

“If I have seen further, it is by standing on the shoulders of giants.”

―Sir Isaac Newton

I stood on the shoulders of those who came before me who were

ignored, defunded, censored, and discredited for daring to tell the truth

about fluoride. They were silenced for being scientifically inconvenient.

Their data was buried, credibility attacked, careers quietly dismantled,

and voices muted, but their courage was the bedrock of my future.

Fluoride wasn’t just in the water. It was in the culture—in

assumptions, in institutions, in policies that protect industry over

people. I wasn’t just up against misinformation. I was up against an

empire. They didn’t follow the science—they followed the script.

Respectfully,

Brenda Staudenmaier
https://www.fluoridelawsuit.com/science
Fluoride Harm: Suppressed Science and Silenced Voices https://www.amazon.com/dp/1069802204/

Open Letter to Karen Black and the Eastman Institute for Oral Health

Dear Ms. Black,

As the Wisconsin mother who sued the U.S. Environmental Protection Agency over the neurotoxicity of fluoridation chemicals — and won — I read your recent article, “Community Water Fluoridation Works: EIOH Debunks Myths, Highlights Lifelong Benefits,” with deep concern.

Your piece echoes the same public relations language used by agencies and dental trade groups that have spent decades defending this outdated policy — even as modern science proves it unsafe. What you published wasn’t objective science communication; it was damage control.

The article’s talking points — claiming “high-quality evidence consistently shows fluoridation poses no risk” — are not only false, they directly contradict the findings presented under oath in federal court. The 2024 decision in Food & Water Watch et al. v. EPA concluded that fluoridation chemicals present an “unreasonable risk” to the developing brain. That conclusion came after years of review of the world’s best evidence — including studies funded by the U.S. National Institutes of Health, published in top medical journals, and vetted by world-class scientists.

Your article also dismisses “foreign studies” that reported IQ loss — yet ignores the NIH-funded research from Canada, Mexico, and the U.S. that found prenatal fluoride exposure at levels typical in fluoridated communities leads to significantly lower IQ scores in children. Those are not fringe findings — they are among the most rigorous developmental neurotoxicity studies ever conducted on a drinking water contaminant.

Even more recently, a 2025 study in Environmental Health found that higher lifetime fluoride exposure was linked to an increased risk of bone fractures — a result that aligns with long-standing evidence of fluoride’s impact on bone brittleness and accumulation in the skeleton. "Among females aged over 50 years, an association of drinking water fluoride with fragility fracture risk started as early as around 0.5 mg/L (risk ratio of 1.26 at 1.0 mg/L)." That’s not “low-quality evidence”; it’s emerging confirmation that this chemical affects multiple systems in the body, not just the teeth. 

So when your headline claims that Eastman Institute scientists “debunk myths,” I have to ask:
Whose myths? Because it certainly isn’t the public’s misunderstanding — it’s the myth that fluoride at 0.7 mg/L is unquestionably safe.

Fluoride defenders have spent years repeating this narrative to protect policy — not people. It’s the same playbook used by the tobacco industry: deny harm, attack scientists who raise alarms, and accuse critics of “politicizing science.” But the real politicization comes from institutions that refuse to confront evidence when it threatens their legacy programs or reputations.

As a mother, I didn’t set out to take on the EPA. I just wanted the truth. What I found was a system that protects policy over children. The federal court case forced the evidence into the open — and the evidence is clear: fluoride is a developmental neurotoxin, and water fluoridation places the entire population at risk of harm.

We’ve compiled an extensive archive of peer-reviewed research at FluorideLawsuit.com/science — a collection of studies published since the U.S. Department of Health and Human Services lowered the fluoridation target to 0.7 ppm in 2015. These papers provide compelling evidence that 0.7 ppm is neither optimal nor safe, and that continuing fluoridation while ignoring such data amounts to unethical human experimentation without consent.

It’s time for journalists and university communicators to rise above the spin. History will not be kind to those who helped prolong public exposure to a known neurotoxicant in the name of “public health.”

Sincerely,

Brenda Staudenmaier

Plaintiff, Food & Water Watch et al. v. EPA
https://www.fluoridelawsuit.com/science

When the FDA announced in mid-2025 that it would finally review the safety and legality of ingestible fluoride supplements for kids, the American Dental Association (ADA) rushed out a form letter and call to action urging dentists to flood the docket with copy-and-paste comments. That page has since vanished from the ADA’s website.

Normally, a removed page can be retrieved through the Wayback Machine, but in this case the archive shows the message:

Hrm. The Wayback Machine has not archived that URL.

(https://web.archive.org/web/20250716182035/https://www.ada.org/advocacy/legislative-action-center/fluoride-regulation)

Yet screenshots taken before the ADA scrubbed its site confirm that the page did exist, and a before-and-after comparison image appears on the left side of this article. In other words, the ADA’s call to action was published, promoted, and then deliberately erased from public view.

The missing page matters because it wasn’t neutral—it was loaded with boilerplate talking points portraying unapproved pediatric fluoride tablets and drops as “vital,” “clinically supported,” and unfairly threatened by “regulatory overreach.” In reality, almost every line misrepresents the science, the regulatory history, or the actual state of pediatric dentistry in 2025.

This was their call to action:

Call to Action:
The FDA has proposed taking pediatric ingestible fluoride supplement drug products off the market—a decision that would eliminate access to fluoride tablets and drops used to prevent tooth decay in children without adequate fluoride in their drinking water.
Dentists: Your voice is urgently needed.
Comment Deadline: July 16, 2025, 11:59 p.m. ET
Public Meeting: July 23, 2025, in person and online
These products are clinically supported and vital for vulnerable children, yet FDA is acting on inconclusive evidence and public pressure to eliminate them. The ADA is submitting official comments and strongly urges all members of the profession to speak out.

Here’s how you can help:

• Submit Your Comment: Fill out the form on this page to submit our prewritten language to comment on this regulation. Or please feel free to personalize your comment.

• Register for FDA’s Public Meeting: Attend in person or online on July 23 to hear perspectives and voice support (https://www.regulations.gov/docket/FDA-2025-N-1557).
  We need the profession to act now—before these fluoride supplements are lost to regulatory overreach.

Form Letter Sent on Behalf of the ADA:

As a licensed dentist and oral health provider, I write to express strong concern over FDA’s proposal to remove orally ingestible fluoride prescription drug products for children from the market.

Fluoride tablets and drops are an important tool for preventing tooth decay in children, especially those living in areas without access to fluoridated drinking water or who have limited ability to use topical fluoride. These products are supported by decades of clinical use and recommended by both the American Dental Association and the U.S. Preventive Services Task Force.

FDA has cited emerging safety concerns, but the majority of studies referenced involve fluoride levels significantly higher than those found in U.S. prescription products or lack methodological rigor. These concerns must be weighed against the well-established public health benefits of fluoride in preventing early childhood caries.

Importantly, this action would remove a valuable clinical option and limit parents’ ability to choose an evidence-based preventive measure for their children. While FDA and HHS officials have publicly emphasized the importance of respecting parental freedom in health care decisions, this proposal effectively eliminates a choice, despite its safety, affordability, and long-standing public health value.

I urge FDA to preserve access to prescription fluoride supplements and ensure that any regulatory decision is guided by high-quality scientific evidence and a commitment to preserving clinician and parent choice in pediatric care.

The author, Jess Steier, DrPH, Founder and CEO of Unbiased Science, is the type of “scientist for hire” we used to see working for the tobacco industry. She receives sponsorship from Arcora, one of the strongest fluoride lobbying groups in the U.S.

Debunking the “Unbiased Science” fluoridation piece published in Smart Water Magazine on 08/09/2025. 

1) “The scientific consensus is clear … safe, effective, essential.”

Reality: The science is contested and evolving. In August 2024 the U.S. National Toxicology Program (NTP) released its final monograph on Fluoride Exposure and Neurodevelopment. It concluded that higher fluoride exposures are associated with lower IQ in children, supported by meta-analyses (including a 2025 JAMA Pediatrics meta-analysis). The NTP also notes evidence is uncertain at typical U.S. water-only levels, which is not the same thing as “clear and safe.” 

Separately, in September 2024 a federal judge ruled under TSCA that fluoridation at 0.7 mg/L presents an “unreasonable risk” and ordered EPA to act; EPA has appealed, so policy is unsettled—but the court explicitly rejected the “settled and safe” framing. 

2) “NTP and meta-analyses only examine ≥1.5 mg/L, irrelevant to U.S. programs.”

Reality: False. The literature NTP evaluated spans a range of exposures and includes prospective birth cohorts in North America with urinary fluoride levels typical of fluoridated cities:

Canada (MIREC): Higher maternal urinary fluoride (median ≈0.4–1.0 mg/L) associated with lower child IQ, particularly in boys (JAMA Pediatrics 2019). 

Mexico (ELEMENT): Prospective cohorts linked prenatal fluoride to lower IQ at 4–12 years. 

NTP’s page summarizes: decreased IQ findings were based primarily on epidemiology where some pregnant women/children living at 0.7mg/L fluoridated water areas had total fluoride intake above what would correspond to ~1.5 mg/L water—but the underlying studies include individual-level urinary biomarkers and dose-response analyses, not just high-fluoride villages. That directly contradicts the article’s claim. 

3) “Studies are just cross-sectional and don’t control confounding.”

Reality: Misleading. The key North American studies are prospective (not cross-sectional) and adjust for numerous confounders (e.g., maternal education, smoking, co-exposures). The 2025 JAMA Pediatrics systematic review/meta-analysis (74 studies; 10 cohorts) found a significant inverse association between fluoride exposure and children’s IQ, including dose-response with urinary fluoride. 

4) “Only 0.6% of Americans see ≥1.5 mg/L, so findings are irrelevant.”

This statistic refers to naturally high-fluoride systems and is often cited from media summaries; it’s not a blanket dismissal of risk. More importantly, the core signal is seen with individual biomarker exposure (urine), not just extreme water concentrations. Policy needs to consider total intake (water, tea, formula, dental products), body weight, and windows of vulnerability (pregnancy, infancy). 

5) “Pharmaceutical-grade additives at precisely monitored levels.”

Reality: U.S. utilities typically use water treatment-grade fluoridation chemicals (e.g., fluorosilicic acid) certified to NSF/ANSI Standard 60—not “pharmaceutical-grade.” CDC’s own materials emphasize product certification and impurity limits under NSF 60. Trace arsenic is controlled by this standard, but the claim of “pharmaceutical-grade” is incorrect. 

6) “25% cavity reduction and $20 savings per $1 invested.”

Those figures are CDC talking points drawn largely from older contexts (prevalent when toothpaste use and other fluoride exposures were lower). The 2015 Cochrane Review—gold-standard methods—found the evidence base for caries reduction is of low quality and mostly pre-1975, and benefits in modern, toothpaste-saturated settings are smaller and uncertain in adults. Cost-savings estimates typically do not incorporate potential neurodevelopmental costs flagged by NTP and the federal court. 

PubMed

7) “Removing fluoride widens disparities—look at Calgary.”

Calgary studies did observe higher caries after cessation, but attributing all changes to fluoridation removal is risky: multiple concurrent policy and behavioral factors (sugar intake trends, dental service access, sealant programs, immigration/demographics, COVID-era disruptions) can confound outcomes. Meanwhile, equity-focused alternatives (e.g., Scotland’s Childsmile: universal toothbrushing in nurseries + targeted support) reduced caries and inequalities and were cost-saving, without medicating the water supply. Equity can be achieved without systemic fluoride dosing. 

Environmental Health Perspectives

PMC

NIHR Evidence

8) “Fluoridation helps prevent cardiovascular disease, cognitive decline, respiratory infections.”

Reality: This is an overreach. Fluoridation’s primary, supported outcome is caries prevention. Evidence that community water fluoridation lowers risks of cardiovascular or respiratory disease is not established. Conflating periodontal-systemic links (which are real) with proof that CWF prevents those diseases is unsupported. Cochrane and public-health reviews emphasize dental outcomes, not systemic disease reduction. 

PubMed

9) “Safety for infants and pregnancy.”

Even CDC advises that exclusively mixing infant formula with fluoridated water can increase the chance of dental fluorosis, and suggests using low-fluoride water some of the time—an implicit acknowledgement of dose sensitivity in early life. Given NTP’s conclusions and the prospective cohort data, prudence during pregnancy and infancy (e.g., minimizing avoidable fluoride intake) is scientifically reasonable. 

CDC

10) Policy landscape isn’t “settled.”

The TSCA ruling (July 2025) found unreasonable risk at 0.7 mg/L and ordered EPA action; EPA has appealed. Separately, HHS leadership signaled intent in April 2025 to revisit CDC recommendations (policy still in flux). Whatever one’s position, claiming a stable, unanimous “consensus” ignores current legal and federal review dynamics. 

CDC

Office of Dietary Supplements

Politico

What this means for water utilities

Legal & scientific due diligence: The TSCA decision changes your risk calculus. Track EPA’s response and incorporate total exposure and sensitive subpopulations (pregnant women, formula-fed infants) into risk management. 

CDC

Stop saying “pharmaceutical-grade”: Use accurate language—NSF/ANSI 60–certified water treatment chemicals—and disclose impurity specs transparently. 

Fluoride Action Network

Equity without exposure: Evaluate Childsmile-style programs (supervised toothbrushing, dental health workers, sealants, sugar policies). They can reduce caries and inequalities and are cost-saving, without systemic dosing. 

PMC

NIHR Evidence

Communicate honestly about uncertainty: CDC still recommends 0.7 mg/L, but NTP findings and the court ruling warrant precaution, particularly for pregnant households and infant formula mixing guidance. Provide practical options (low-fluoride water, filters with certified fluoride reduction). 

CDC

Bottom line

The article’s sweeping claims—“clear consensus,” “irrelevant studies,” “pharmaceutical-grade additives,” and systemic disease prevention—don’t align with the current evidence or the current legal reality. The prudent, science-based position for utilities today is nuanced risk management, targeted caries-prevention strategies, and transparent communication—not absolutist assurances.

Prenatal fluoride exposure and infant motor development in Los Angeles, California (#237)

D. Khan1, S. P. Eckel2, I. Hernandez-Castro3, H. Hu2, T. Yang2, S. F. Farzan2, C. V. Breton2, T. M. Bastain2, A. J. Malin1

1 University of Florida, Epidemiology; College of Public Health and Health Professions; College of Medicine, Gainesville, Florida, United States of America

2 University of Southern California, Department of Population and Public Health Sciences, Keck School of Medicine, Los Angeles, California, United States of America

3 Stanford University, Department of Epidemiology and Population Health, Stanford Medicine, Stanford, California, United States of America

Background: Chronic prenatal fluoride exposure, at United States (US) population relevant levels, has been associated with worse child neurodevelopment; however, to our knowledge, no US-based study has examined these associations in infants. This study investigated associations between maternal urinary fluoride during pregnancy and infants’ motor developmental outcomes among mother-child pairs in Los Angeles, California.

Methods: Participants were from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort. MADRES is a prospective pregnancy and birth cohort of predominantly Hispanic women with low income living in urban Los Angeles. Specific gravity-adjusted maternal urinary fluoride (MUFsg) in the third trimester was used as a biomarker of fluoride exposure. Infant motor development at 6, 9, 12, and 18-months was assessed with the Ages and Stages Questionnaire-3 (ASQ). Fine and gross motor development scores were reverse coded, such that higher scores indicate worse performance. Longitudinal negative binomial regression examined associations between MUFsg and ASQ scores adjusted for maternal age, race, income, BMI, child sex and corrected age at ASQ assessment.

Results: Among 347 mother child pairs, the median (IQR) MUFsg was 0.79 (0.54) mg/L. In longitudinal models, higher third trimester MUFsg was marginally associated with higher gross motor score (IRR=1.13, 95% CI: 0.99, 1.29, p=0.06), and higher fine motor score (IRR=1.13, 95% CI: 1.00, 1.27, p=0.05), indicating worse performance. There was no evidence for associations with other ASQ scores [problem solving (IRR=0.99, 95% CI: 0.82,1.19), personal-social score (IRR=1.01, 95% CI: 0.86,1.19), communication score (IRR=0.94, 95% CI: 0.79,1.12)].

Conclusions: Prenatal fluoride exposure may be associated with developmental neurotoxicity manifesting in infancy. Additional studies are needed to further explore this association in different regions and across the nation.

Prenatal Fluoride Exposure and Neuropsychological Outcomes in the New Hampshire Birth Cohort Study (#238)

C. V. Goodman1, M. Karagas2, J. Peacock2, S. Korrick3, D. Flora1, B. Lanphear4, E.A. Martinez-Mier5, G. Tamayo-Cabeza5, G. Castiblanco5, F. Lippert5, C. Till1

1 York University, Department of Psychology, Toronto, Ontario, Canada

2 Dartmouth College, Department of Epidemiology; Geisel School of Medicine, Hanover, New Hampshire, United States of America

3 Harvard University, Harvard T.H. Chan School of Public Health and Brigham Women’s Hospital, Boston, Massachusetts, United States of America

4 Simon Fraser University, Faculty of Health, Burnacy, British Columbia, Canada

5 Indiana University, Indiana University School of Dentistry, Indianapolis, Indiana, United States of America

Background: Fluoride has been associated with deficits in intelligence, and increased externalizing and internalizing problems, but the neuropsychological domains most sensitive to fluoride remain unclear.

Objective: We examined whether prenatal fluoride exposure is associated with children’s neuropsychological outcomes in the New Hampshire Birth Cohort Study (NHBCS).

Methods: Our analysis included 358-409 mother-child dyads from the NHBCS. Fluoride was measured in toenails collected at ~24-28 weeks’ gestation (referred to as 24-week toenail fluoride; 24WTF) and ~6 weeks postpartum (6WPTF), reflecting exposures in early- to mid-pregnancy. Children’s cognition, motor function, and behaviour were assessed at age 5 years. Generalized estimating equations were applied to estimate the association between toenail fluoride and neuropsychological outcomes, modeling behavioural measures with odds ratios for T-scores≥60. Covariates included child sex, maternal education, maternal age, and study site. Effect modification by child sex was evaluated.

Results: Median (IQR) μg/g fluoride concentration were 2.77 (1.90) for 24WTF and 2.13 (1.42) for 6WPTF. In a complete case analysis, 24WTF was associated with higher odds of depression in girls (OR=1.82 [1.19, 2.79]), but not boys (p-for-interaction=0.007). 24WTF was associated with elevated odds of hyperactivity (OR=1.20 [1.01, 1.43]) and externalizing problems (OR=1.39 [1.15, 1.67]) in both sexes; a similar pattern was observed with 6WPTF. Associations differed between toenail sampling times and child sex for working memory (p-for-interaction=0.044); among girls, 24WTF was associated with decreased working memory (β=-1.24, [ –2.40, –0.09]); no association was observed for boys or for 6WPTF in either boys or girls. A 6WPTF-by-sex interaction was observed for fine motor precision (p-for-interaction=0.032), with higher fluoride related to lower fine motor precision among boys (β=–0.35 [–0.70, 0.01]), but not girls.

Conclusions: Preliminary findings from this U.S. cohort suggest that prenatal fluoride exposure is associated with sex- and domain-specific effects on children’s neuropsychological outcomes; however, further analyses are needed.

Prenatal fluoride exposure and child sleep behaviors in a nationally representative Canadian cohort (#239)

Z. Wang1, C. Till2, M. Hall2, J. El-Sabbagh2, G. Muckle3, J. Séguin4, L. Booij5, K. Boylan6, C. Panagiotopoulos7, K. Morrison8, M. Bouchard9, B. Lanphear10, A. J. Malin1

1 University of Florida, Epidemiology; College of Public Health and Health Professions; College of Medicine, Gainesville, Florida, United States of America

2 York University, Psychology; Faculty of Health, Toronto, Ontario, Canada

3 Université Laval, psychology; Faculty of Social Sciences, Québec, Québec, Canada

4 Université de Montréal, psychiatrie et d’addictologie; Faculté de médecine, Montreal, Québec, Canada

5 McGill University, Psychiatry; Faculty of Medicine and Health Sciences, Montreal, Québec, Canada

6 Mcmaster University, Psychiatry & Behavioural Neurosciences; Faculty of Health Science, Hamilton, Ontario, Canada

7 University of British Columbia, Pediatrics; Faculty of Medicine, Vancouver, British Columbia, Canada

8 McMaster University, Pediatrics; Faculty of Health Sciences, Hamilton, Ontario, Canada

9 Institut National de la recherche scientifique, Armand-Frappier Santé Biotechnologie Research Centre, Laval, Québec, Canada

10 Simon Fraser University, Health Science; Faculty of Health Science, Burnaby, British Columbia, Canada

Objective: Fluoride accumulates in the pineal gland, which produces melatonin, the hormone that regulates sleep. We examined associations between maternal fluoride exposure during pregnancy and sleep patterns in Canadian children.

Materials and Methods:

Participants included mother-child pairs from the Maternal-Infant Research on Environmental Chemical (MIREC) cohort. We measured urinary fluoride concentrations (UFC; mg/L) in spot urine samples collected during each trimester and adjusted for specific gravity (n= 433). Water fluoride concentrations (WFC; mg/L) were ascertained from municipal water treatment reports (n=370). Covariate-adjusted linear and logistic regression analyses examined associations between fluoride exposures and sleep behaviors self-reported by the child (n=421 for UFC; n=361 for WFC) and accelerometer-derived sleep outcomes in a subsample (n=89 for UFC; n=74 for WFC). Covariates included mothers’ education level, marital status, race, annual household income, age, urbanicity, and child’s sex and age; we also included city for models using UFC as a predictor.

Results:

Children’s ages ranged from 7 to 13 years. Median (interquartile range; IQR) UFC and WFC were 0.50 (0.39) mg/L and 0.52 (0.52) mg/L, respectively. Each 1-IQR increase in WFC was associated with a 10-minute later self-reported weekday bedtime (B = 10.40, 95% CI: 0.83, 19.97, p=0.04), and 1.73 times the odds of snoring compared to not snoring (OR = 1.73, 95% CI: 1.04, 2.88, p=0.04). Each IQR increase in UFC was associated with a 14-minute later bedtime (B=13.57,95%CI: 2.05, 25.09, p = 0.02), an 11-minute later child sleep midpoint (B=11.42,95%CI: 1.13, 21.72, p = 0.03), and a trend of later wake-up time (B=9.25,95%CI:-1.42, 19.92, p = 0.09) all assessed via accelerometry.

Conclusion:

In this Canadian cohort, children with higher prenatal fluoride exposure had later bedtimes, later sleep midpoint, and higher odds of snoring. Studies employing polysomnographic assessment of sleep are needed further to explore potential effects of fluoride on sleep patterns.

Urinary Fluoride Concentration is Associated with Structural Changes in the Adolescent Brain (#241)

K. M. Cecil2, K. J. Brunst1

1 University of Cincinnati, Environmental Health; College of Medicine, Cincinnati, Ohio, United States of America

2 University of Cincinnati, Departments of Radiology, Pediatrics, Environmental and Public Health Sciences, Cincinnati, Ohio, United States of America

Despite the emerging evidence of fluoride's adverse impact on neurobehavioral outcomes, the impact on brain structure is unclear. Using magnetic resonance imaging (MRI), we examined the relationship between childhood urinary fluoride and brain structure, featuring morphometrics of brain volume, cortical thickness and curvature, while also exploring sex effects.

Data from participants (n=329, median 12.1 years (range 11-14.7), 166 female) enrolled in the Cincinnati Combined Childhood Cohorts (C4) Study collected at the 12-year study visit were used for this study. Dilution-corrected childhood urinary fluoride (CUF) concentrations were determined, adjusted for specific gravity and log-transformed. High-resolution, three dimensional T1-weighted images were collected using a 3 Tesla MRI scanner and analyzed with FreeSurfer software to determine whole and subcortical brain volumes, with the cortex parcellated to determine volume, thickness and curvature measurements. Each regional volume, cortical thickness and curvature metric was compared to CUF using covariate-adjusted general linear models including participant sex, maternal age at delivery, household income, neighborhood deprivation index score, maternal depression score, blood lead, household smoking status and total intracranial volume. Sex-interaction and stratified models were developed. The models were adjusted for multiple comparisons.

CUF concentration was 1.12 + 0.72 (range 0.31 – 7.78) mg/mL. Increases in CUF were associated with greater cortical thickness among several brain regions including the left inferior temporal gyrus, left pars orbitalis, right middle temporal gyrus and right fusiform gyrus in females. Associations of CUF and measures of cortical curvature were observed in males. However, no associations with CUF and volume metrics were observed.

Significant fluoride associated cortical thickness changes were observed in regions implicated in perception, language processing and social cognition, which may reflect delays in brain maturation. Understanding the impact on neurodevelopment is essential to protecting pediatric health and making informed decisions about appropriate fluoride exposure in public health settings.

Dental Fluorosis and Depression Among Young Adults in the United States (#243)

A. M. Miles1, 2, D. Khan2, A. Mattia2, Z. Wang2, A. J. Malin2

1 University of Florida, Rehabilitation Science; College of Public Health and Health Professions, Gainesville, Florida, United States of America

2 University of Florida, Department of Epidemiology, College of Public Health and Health Professions, College of Medicine, Gainesville, Florida, United States of America

Objective

Fluoride exposure can contribute to depressive symptoms in animals, even at low levels; however, to our knowledge, no human studies have examined this association. We investigated associations between dental fluorosis (a proxy for excess fluoride exposure during tooth development) and depression in young adults in the United States (US).

Materials and Methods

The study included 886 adults aged 18-29 years from the National Health and Nutrition Examination Survey (NHANES) 2015-2016. Fluorosis was assessed using the Dean's Fluorosis Index (DFI). Participants with a DFI score ≥ 1.0 had fluorosis ranging from very mild to severe; we classified those with a DFI ≤ 0.5 (i.e., normal/questionable fluorosis) as not having fluorosis. Depression was measured using the Patient Health Questionnaire (PHQ-9). We classified participants as having major depression if they scored ≥10 and satisfied certain clinical criteria. We also classified depression severity as no depression (score < 5), minimal symptoms/mild depression (score 5-14), and moderately severe/severe depression (score >=15). Survey-weighted and covariate-adjusted binomial and multinomial logistic regression examined associations of dental fluorosis with presence and severity of depression, respectively. Covariates included age, gender, race/ethnicity, BMI, income, and serum cotinine.

Results

Participants were 24 years-old on average and males and females were evenly distributed. Approximately 70% of participants had dental fluorosis and 5% reported currently experiencing major depression. Participants with dental fluorosis were 1.8 times more likely to report current major depression compared to those without fluorosis (OR=1.78; 95% CI: 1.03, 3.07; p=0.04). Dental fluorosis was not associated with severity of depressive symptoms (OR=1.23, 95% CI: 0.56, 2.69; p=0.59 for minimal symptoms/mild depression; OR=1.03,95% CI: 0.27, 3.98; p=0.96 for moderately severe/severe depression, compared to no depressive symptoms).

Conclusion

Excess fluoride exposure during tooth development is associated with higher odds of major depression in adulthood. Prospective studies are needed to further examine this association

These studies have been archived on my website for many years and were done using US data:

NHANES Reports Relevant to Fluoridation Harm

1.     INFLAMMATION: “Our finding that neutrophils and monocytes are associated with higher plasma fluoride in U.S. children and adolescents is consistent with animal data showing fluoride related effects of increased inflammation.” https://ehjournal.biomedcentral.com/articles/10.1186/s12940-022-00911-6

•       Den Besten P, Wells CR, Abduweli Uyghurturk D. Fluoride exposure and blood cell markers of inflammation in children and adolescents in the United States: NHANES, 2013-2016. Environ Health. 2022 Oct 27;21(1):102.

2.     KIDNEYS: “Water fluoridation results in higher plasma fluoride levels in those with lower renal function. How routine water fluoridation may affect the many millions of Americans with Chronic Kidney Disease, who are particularly susceptible to heavy metal and mineral accumulation, needs to be further investigated.”

https://pubmed.ncbi.nlm.nih.gov/35688217/

•       Danziger J, Dodge LE, Hu H. Role of renal function in the association of drinking water fluoride and plasma fluoride among adolescents in the United States: NHANES, 2013-2016. Environ Res. 2022 Oct;213:113603.

3.     LIVERS & KIDNEYS: “Fluoride exposure may contribute to complex changes in kidney and liver related parameters among U.S. adolescents. As the study is cross-sectional, reverse causality cannot be ruled out; therefore, altered kidney and/or liver function may impact bodily fluoride absorption and metabolic processes.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6754771/

•       Malin AJ, Lesseur C, Busgang SA, Curtin P, Wright RO, Sanders AP. Fluoride exposure and kidney and liver function among adolescents in the United States: NHANES, 2013-2016. Environ Int. 2019 Nov;132:105012.

4.     BLOOD PRESSURE: “This study suggested that fluoride exposure may affect childhood blood pressure.” https://pubmed.ncbi.nlm.nih.gov/35168424/

•       Guo M, Afrim FK, Li Z, Li N, Fu X, Ding L, Feng Z, Yang S, Huang H, Yu F, Zhou G, Ba Y. Association between fluoride exposure and blood pressure in children and adolescents aged 6 to19 years in the United States: NHANES, 2013-2016. Int J Environ Health Res. 2022 Feb 15:1-11.

5.     LOW BIRTH WEIGHT & ENVIRONMENTAL JUSTICE: “Our findings suggest a significant association between excess water fluoride exposure (>0.7 ppm) and LBW weight in Hispanic women, independent of established LBW risk factors.” https://pubmed.ncbi.nlm.nih.gov/35897326/

•       Arun AK, Rustveld L, Sunny A. Association between Water Fluoride Levels and Low Birth Weight: National Health and Nutrition Examination Survey (NHANES) 2013-2016. Int J Environ Res Public Health. 2022 Jul 23;19(15):8956.

6.  DENTAL FLUOROSIS; “The prevalence of dental fluorosis was 70% in the U.S. children and adolescents in survey of NHANES 2015–2016.” https://pubmed.ncbi.nlm.nih.gov/34166938/

•       Dong H, Yang X, Zhang S, Wang X, Guo C, Zhang X, Ma J, Niu P, Chen T. Associations of low level of fluoride exposure with dental fluorosis among U.S. children and adolescents, NHANES 2015-2016. Ecotoxicol Environ Saf. 2021 Sep 15;221:112439.

7.     REPRODUCTIVE HEALTH: “Median (IQR) water and plasma fluoride levels were 0.48 (0.53) mg/L and 0.34 (0.30) µmol/L respectively. An IQR increase in water fluoride was associated with a 3.3 month earlier first menstrual period (B= -0.28, 95%CI: -0.54, -0.02, p = 0.05). Additionally, we observed a significant interaction between plasma fluoride and race/ ethnicity in association with age of menarche (p = 0.01). For non-Hispanic black females, each IQR increase in plasma fluoride was associated with a 5-month earlier age of menarche (B=-0.42, 95%CI: -0.61, -0.23, p < 0.001).” https://ehp.niehs.nih.gov/doi/abs/10.1289/isee.2020.virtual.O-OS-619

•       Fluoride exposure and reproductive health among adolescent females in the United States: NHANES 2013-2016. A. J. Malin, S. A. Busgang, J. C. Garcia, P. Curtin, and A.P. Sanders. ISEE National Meeting Presentation. Environmental Health Perspectives. 23-26 August 2021.

8.  DENTAL FLUOROSIS: “In 2001-2002, the weighted percentage prevalence of the denoted dental fluorosis categories were: 49.8% normal (i.e., unaffected), 20.5% questionable, and 29.7% very mild and above. In 2011-2012, the weighted percentage prevalence categories were: 31.2% normal, 7.5% questionable, and 61.3% very mild and above. When comparing years 2001-2002 with the years 2011-2012, the prevalence of very mild and above fluorosis increased by 31.6% (P <.0001) for the 2011-2012 group.” “There was a difference of 31.6% in dental fluorosis prevalence between 2012-2011 when compared to data from 2002-2001 in adolescents aged 16 and 17 years. The continued increase in fluorosis rates in the U.S. indicates that additional measures need to be implemented to reduce its prevalence.” https://pubmed.ncbi.nlm.nih.gov/29500282/

•       Wiener RC, Shen C, Findley P, Tan X, Sambamoorthi U. Dental Fluorosis over Time: A comparison of National Health and Nutrition Examination Survey data from 2001-2002 and 2011-2012. J Dent Hyg. 2018 Feb;92(1):23-29.

9.  FLUORIDE & DEMOGRAPHICS: “About 30% of the children were at the risk of dental fluorosis.” https://pubmed.ncbi.nlm.nih.gov/28110134/

•       Jain RB. Concentrations of fluoride in water and plasma for US children and adolescents: Data from NHANES 2013-2014. Environ Toxicol Pharmacol. 2017 Mar;50:20-31.

10.  SLEEP PATTERNS: “Fluoride exposure may contribute to changes in sleep cycle regulation and sleep behaviors among older adolescents in the US. Additional prospective studies are warranted to examine the effects of fluoride on sleep patterns and determine critical windows of vulnerability for potential effects.” https://pubmed.ncbi.nlm.nih.gov/31818308/

•       Malin AJ, Bose S, Busgang SA, Gennings C, Thorpy M, Wright RO, Wright RJ, Arora M. Fluoride exposure and sleep patterns among older adolescents in the United States: a cross-sectional study of NHANES 2015-2016. Environ Health. 2019 Dec 9;18(1):106.