Concerns and Questions about the Draft NTP Monograph on the Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects
As a scientist who highly values the fair, relevant and accurate evaluation and presentation of scientific study conclusions – and who trusts the process of formulating, reviewing and adjusting (when required) any well-established scientific consensus – I have some serious concerns and questions about the DRAFT NTP MONOGRAPH ON THE SYSTEMATIC REVIEW OF FLUORIDE EXPOSURE AND NEURODEVELOPMENTAL AND COGNITIVE HEALTH EFFECTS that I would appreciate having answered as part of the review process.
I understand from information
on page 3 that in
2015 this NTP “review
was initiated in response to a nomination from the
Fluoride Action Network.”, fluoridealert.org was
searched for publications, and the foreign language
studies were translated by the Fluoride Action Network.
Fluoride Action Network hardly constitutes an unbiased
scientific institution.
Community water fluoridation
(CWF) is an important, well established public health
measure for reducing the risk of dental decay and
related health problems in communities. CWF
programs depend not only on the scientific consensus of
relevant experts but on the perception of residents who
are not scientists or health care professionals but who
contribute to the democratic process – either as voters
or governmental officials who ultimately determine the
fate of public health measures.
It is critical that this
review take into account the potential for dismantling
CWF programs worldwide if the current wording, “that fluoride is presumed to be a
cognitive neurodevelopmental hazard to humans”
is retained – particularly when the review as presented
does not seem to confirm that significant, verifiable
conative harm occurs at levels below 1.5 ppm.
Fluoridation opponents who have been pushing to acquire
legitimate scientific support for decades will have just
the phrase they need to scare more people into voting to
discontinue CWF. They were disappointed with the
2016 NTP fluoride review and very upset by conclusions
of the 2018 NTP animal study they pushed for. A primary
conclusion “that
fluoride is presumed to be a cognitive
neurodevelopmental hazard to humans” will create
significant, unwarranted chaos – particularly in the
case of the qualifications critical to exposure levels
in fluoridated water which will be completely ignored.
A recent Bloomburg article,
Public Trust in Tap Water May Hinge on Fluoride Link to
Child IQ, stated, “National
Academies committee to review finding that high fluoride
exposure could decrease children’s IQ. Final
assessment could influence local governments’ decisions
to fluoridate water supplies”
“A federal
agency’s preliminary finding that high concentrations of
fluoride may decrease children’s IQ will, if finalized,
be hard to explain to the public, scientists said Nov.
6.
https://news.bloombergenvironment.com/environment-and-energy/public-trust-in-tap-water-may-hinge-on-fluoride-link-to-child-iq
Unless the NTP review Evaluation Team is able to appraise and reject all the criticisms that I and others present concerning this draft monograph and is able toconclude without a reasonable doubt that ingesting optimally fluoridated water (<1.5 ppm or so) “is presumed to be a cognitive neurodevelopmental hazard to humans“, I would strongly suggest changing the conclusion to: “fluoride at levels of exposure significantly above that found in optimally fluoridated drinking water is presumed to be a cognitive neurodevelopmental hazard to humans”. The Evaluation Team can define the term "significantly above" in a different sentence.
There is an overabundance of fake news available these days, and reputable organizations must do everything possible to avoid inadvertently contributing to it.
Concern 1:
As a scientist, I am concerned that the NTP, SYSTEMATIC
REVIEW OF FLUORIDE EXPOSURE AND NEURODEVELOPMENTAL AND
COGNITIVE HEALTH EFFECTS as titled and presented in
draft form is playing into the hands of
anti-fluoridation activists. Fluoridation Action
Network is already using the conclusion of the draft
review to claim a respected scientific organization
agrees with their opinions on the risks of community
water fluoridation. (Image 1,
below)
http://fluoridealert.org/content/bulletin_10-26-19/
Question
1a: Is the body of scientific
evidence used to formulate the draft NTP
conclusion “that
fluoride is presumed to be a cognitive
neurodevelopmental hazard to humans” accurately,
specifically and statistically relevant to exposure at
levels found in optimally fluoridated water with a
cognitive neurodevelopmental hazard in fluoridated
communities? Or are the results that might
possibly show any potential small association with
cognitive neurodevelopmental issues only
potentially demonstrated at higher exposure levels than
found in optimally fluoridated communities as noted in
the review? If so, exposure at the lower levels
(<1.5 ppm) can hardly be labeled a “presumed
hazard”.
Question
1b: since this review will be
primarily used to formulate and assess community water
fluoridation practices,
why was the scope
not restricted to study conclusions that were relevant
to exposure at levels found in optimally fluoridated
communities? Explain why the review was not
titled SYSTEMATIC REVIEW OF COMMUNITY WATER FLUORIDATION
RELATED TO POSSIBLE NEURODEVELOPMENTAL AND COGNITIVE
HEALTH EFFECTS??? If that were the focus of the
review, the conclusions which would have been an
accurate description of findings would be: “There
is insufficient evidence to conclude that exposure to
fluoride ions at levels more than twice those in
optimally fluoridated water can be presumed to be a
cognitive neurodevelopmental hazard to humans. The
studies that have examined a possible correlation
between exposure to fluoride ions below 0.5 ppm have
reported conclusions that have varied widely from no
association, to weak positive and negative associations
in all children, to conflicting differences between boys
and girls.”
===========================================
Concern 2: As a scientist, it is my assessment that the NTP Fluoride Exposure Draft Monograph contains significant, unwarranted, unscientific conclusions. Specifically the wording (P 2 & 59), “NTP concludes that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans. This conclusion is based on a consistent pattern of findings in human studies across several different populations showing that higher fluoride exposure is associated with decreased IQ or other cognitive impairments in children. However, the consistency is based primarily on higher levels of fluoride exposure (i.e., >1.5 ppm in drinking water).” is both false and irresponsible with absolutely no relevant context until the third sentence – which makes it prime fodder for anti-science activists – see Concern 3.
In fact, the phrase “fluoride is presumed to be a cognitive neurodevelopmental hazard”
was used ten times in the review. The word “presumed”
has a completely different meaning and a significantly
greater negative bias than the conclusions actually
stated in most studies referenced which only concluded
there may be a possible “association”
or “correlation”
between exposure to fluoride ions and a given
neurological issue.
The NTP
conclusion seems to be an example of an irresponsible,
blanket claim of harm:
(a)
without noting how weak the reported
“associations” or “correlations” were. The
strongest association, to my knowledge, was about 5%
with huge scatter. That means 95% of any
“association/correlation” would have other causes – and,
of course, correlation does not mean causation (or a
presumed hazard);
(b)
that completely ignores the significant
limitations of the studies reviewed (addressed in other
questions);
(c)
without any context of the actual
exposure levels;
(d)
without highlighting the wide variety of outcomes
reported in other studies (from no association to some high or low
associations to different associations based on sex or
age);
(e)
without apparent consideration of the fact the two
studies (Bashash, et al, and Green, et al.) referenced
(P 49 & 52) as “two
well-designed and well-conducted Canadian and Mexican
prospective cohort studies of children” used
data from the ELEMENT and MIREC studies which were not
designed to test the fluoride and IQ hypothesis.
Concern 2a
& b, weak association & study limitations:
Since many of the studies reviewed in the NTP Monograph
that reported a weak negative correlation/association
between low fluoride levels and neurodevelopmental and
cognitive health effects were published in fairly
obscure journals, they avoided intense scientific
scrutiny and were not widely referenced except by
fluoridation opponents.
The publication of the Green,
et al. study in a fairly respected journal, however,
combined with a very unusual introduction by the editor
and significant resulting publicity changed the dynamic.
There has been a
major, unprecedented response to the Green, et al. study
from many members of the scientific and health
communities around the world who have presented serious
study limitations, and there has been a request by 30
experts for study data for independent analysis.
http://www.cyber-nook.com/water/FluoridationInformation-green.html
Concern 2c,
context: The NTP conclusion of “presumed hazard” is as meaningless as an equally true, but
misleading, statement: “Based
on a review of available evidence, I conclude that H2O
is presumed to be a significant physical hazard to
humans.
Hyperhydration causes symptoms which can lead to injury
and death in children and adults”. The
evidence of potential harm from exposure to water at
levels four to ten times higher than recommended is far
greater than the evidence that exposure to fluoride ions
in drinking water at 4 – 5 times greater than the
recommended level of 0.7 ppm.
https://www.medicalnewstoday.com/articles/318619.php#4
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682940/
“Complications
from acute (>3 L/h) or chronic (5–10+ L/day) water
intakes at rest are uncommon but may result in acute
water intoxication or chronic urinary tract
abnormalities such as urinary bladder distention, ureter
dilation, and hydronephrosis.”
Note, the chronic
over-exposure level is just 3 to 5 times higher than
recommended exposure levels to ingested water. The same
conclusions can be presented regarding exposure to
medicines, vitamins, salt, etc. – they can all be
presumed to be hazardous when exposure levels are
omitted.
Concern 2d,
different outcomes: Another fact
misrepresented in the NTP conclusions is that there is a
“consistent pattern of findings” (P 1, 2 52, 53, 59). In fact,
the pattern is far from consistent in the studies
reviewed which actually demonstrates that there is no
relevant pattern that links exposure to optimally
fluoridated water with lowered IQ or other neurological
issues. In order to make that claim, all of the
significant limitations of the studies that conclude
they found a negative association with fluoride and any
cognitive neurodevelopmental hazard would need to be
dismissed.
=> Some studies
that had conclusions completely contrary to the NTP
conclusion, “that fluoride is presumed to be a cognitive neurodevelopmental hazard to
humans.”
~>
August 2019,
Fluorinated water consumption in pregnancy and
neuropsychological development of children at 14 months
and 4 years of age: (Santa-Marina, et al., Environmental
Epidemiology: October 2019)
“Prenatal
exposure at the levels found in fluorinated drinking
water may exert a beneficial effect
on the development at 4 years of age. At low doses,
fluoride could present a dose-response pattern with a
beneficial effect.”
This study was
not part of the NTP review.
~> From the 2019 NTP Draft Review, P 54: “Surprisingly, three of the studies (Xu et al. 1994, Qin et al. 2008, Aravind et al. 2016) found that the lowest IQ scores were in areas with the lowest and the highest fluoride concentrations”
~>
2014
dissertation,
Fluoride exposure during pregnancy and its effects on
childhood neurobehavior: a study among mother-child
pairs from Mexico City, Mexico, by Deena B. Thomas
used data from the Mexican ELEMENT study which also
provided data for the Bashash, et al. 2017 and 2018 IQ
and ADHD studies. Four of the five members of her
Doctoral Committee and Thomas were coauthors of the
published Bashash, et al. studies. Thomas’
dissertation concluded: “Overall,
this investigation found no evidence of a detectable
adverse outcome on offspring neurobehavioral development
associated with maternal fluoride exposure during
pregnancy.” P 75
“Overall, this
investigation found a significant positive impact
on neurobehavioral development due to ingestion of
fluoride in male children but no association was
detected in female children. Fluoride measured in
urine was significantly associated with total WASI score
in male children ages 6 to 15 years old” P 77
~> 2018 study, "An Evaluation of Neurotoxicity Following Fluoride Exposure from Gestational Through Adult Ages in Long-Evans Hooded Rats", lead by the Neurotoxicology
Group of the NTP concluded, “The
findings of this well-controlled animal study directly
address previous concerns regarding potential biological
plausibility of fluoride as a neurotoxin. The findings
provide valuable information and assurance that
low-level fluoride exposures from water and diet that
are equivalent to the levels allowed in the US does not
result in clinically adverse neurobehavioral function or
pathological effects in various organs.”
Reviewers at Fluoride Science concluded, “The
findings of this well-controlled animal study directly
address previous concerns regarding potential biological
plausibility of fluoride as a neurotoxin. The findings provide valuable information and assurance that low-level
fluoride exposures from water and diet that are
equivalent to the levels allowed in the US does not
result in clinically adverse neurobehavioral function or
pathological effects in various organs.”
~> October 2019, Fluorinated water consumption in pregnancy and neuropsychological development of children at 14 months and 4 years of age: (L, Santa-Marina, et al., Environmental Epidemiology: October 2019) “Conclusions: Prenatal exposure at the levels found in fluorinated drinking water may exert a beneficial effect on the development at 4 years of age. At low doses, fluoride could present a dose-response pattern with a beneficial effect.”
~> January 2015, Community Water Fluoridation and Intelligence: Prospective Study in New Zealand, (Broadbent, et al., Am J Public Health. 2015) “Conclusions. These findings do not support the assertion that fluoride in the context of CWF programs is neurotoxic. Associations between very high fluoride exposure and low IQ reported in previous studies may have been affected by confounding, particularly by urban or rural status.”
~> June 2016, The Effects of Fluoride in the Drinking Water (2016 paper, Aggeborn & Öhman) “We use a rich Swedish register dataset for the cohorts born 1985-1992, together with drinking water fluoride data. To estimate the effect we exploit intra-municipality variation of fluoride, stemming from an exogenous variation in the bedrock. First, we investigate and confirm the long-established positive relationship between fluoride and dental health. Second, we find precisely estimated zero effects on cognitive ability, non-cognitive ability and education. We do not find any evidence that fluoride levels below 1.5 mg/l have negative effects. Third, we find evidence that fluoride improves labor market outcome later in life, which confirms that good dental health is a positive factor on the labor market.”
Concern 2e,
data not designed for fluoride study:
A research team that does not collect their own specific
study data from a population based on a specific study
design must depend on data collected by others.
Eventually, data is extracted from another study
specifically to fit a study proposal. There are a
number of possible situations in which the extracted
data might not have been collected in an appropriate
manner for a different study, or it might not contain
all of the variables necessary to establish a legitimate
association between variables, never mind the
presumption of a presumed hazard.
Questions
relevant to Concerns 2a & b:
~> Has the
NTP review Evaluation Team carefully considered all
of the criticisms presented against the Green, et al.
and Bashash, et al. study designs, data selection, data
evaluation and conclusions – not to mention the other
reviewed studies?
http://www.cyber-nook.com/water/FluoridationInformation-green.html
If so, are any of the criticisms legitimate?
If the NTP has found any criticisms unfounded, provide
the reasons.
If any of the criticisms are legitimate, is it
even remotely accurate to present the studies as, “two
well-designed and well-conducted Canadian and Mexican
prospective cohort studies of children where repeated
maternal urinary fluoride levels were assessed during
pregnancy…”? (p. 52)
~>
Why didn’t the NTP review publish its
conclusions as they were stated in the reviewed papers?
How and why did the NTP review Evaluation Team make the
transition from the actual conclusions of the widely
varied and conflicting studies which, at most, only
stated there was a possible association or
correlation to the published conclusion “fluoride
is presumed to be a cognitive neurodevelopmental hazard”
(used 10 times within the monograph) which implies an
established cause and effect relationship???
~>
Is it appropriate to finalize and publish the
“SYSTEMATIC REVIEW OF FLUORIDE EXPOSURE AND
NEURODEVELOPMENTAL AND COGNITIVE HEALTH EFFECTS” with
the primary conclusion “fluoride is presumed to be a
cognitive neurodevelopmental hazard” before the
many exposed problems, limitations and concerns of
Green, et al. study (and many similar problems,
limitations and concerns of other reviewed studies) have
been adequately addressed by other experts?
An example for consideration
of a more accurate current monograph conclusion
would be: “NTP
concludes that a number of studies have evaluated the
correlation between exposure to fluoride ions and
cognitive neurodevelopmental in humans.
Those studies
have reported many different possible associations or
correlations between cognitive neurodevelopmental
and exposure to fluoride ions, all of which are small
and most occur at exposure levels >1.5 ppm in drinking
water – twice the recommended level in optimally fluoridated water.
The studies have reported a variety of different,
inconsistent and often conflicting findings. Some
studies reported no effect of fluoride exposure levels
at levels equivalent to those in optimally fluoridated
water and higher. Some studies reported a small decrease
in cognitive neurodevelopmental at higher fluoride
exposure levels for all children. Some studies
reported a small increase in cognitive
neurodevelopmental at higher fluoride exposure levels
for all children. Some studies reported a small decrease
in cognitive neurodevelopment for boys but not girls,
and some for girls but not boys at higher exposure
levels. Some studies have reported a decrease in
cognitive neurodevelopmental at both the lowest and at
higher fluoride exposure levels.”
Question
2c: If all substance ingestion or
activities that were beneficial at optimal levels but caused (or were even
associated with or correlated with) potential harm of
some sort at levels 3 to 5 times higher than “normal
levels” were categorized as a “presumed hazard”, what
would be the consequence for most human actions?
For a government entity to selectively and repeatedly
frame an established, beneficial public health measure
that has over 70 years of supporting evidence in a
manner that deliberately makes it appear to be dangerous
is shocking.
http://www.cyber-nook.com/water/FluoridationInformation-Reviews.html
Question 2d: Why didn’t the NTP review Evaluation Team highlight the wide variety of different study outcomes in their conclusions? Even if some studies were evaluated as better than others, the small effects, wide scatter in available graphs, and conflicting conclusions should be a warning to not presume there are any conclusions sufficient to change the current scientific consensus. (Image 2 below)
Question 2e:
Did the NTP review Evaluation Team consider the
possible, significant limitations of using ELEMENT and
MIREC data instead of data actually collected for
investigations specifically designed to study the effect
of fluoride at levels found in optimally fluoridated
water?
==========================================================
Concern
3:
Fluoride Action
Network is already using the NTP draft review in its
propaganda.
http://fluoridealert.org/content/bulletin_10-26-19/
- “On Oct 22, the National
Toxicology Program (NTP) published a
draft review of fluoride’s neurotoxicity concluding:
‘…Fluoride is
presumed to be a cognitive neurodevelopmental hazard to
humans.” & “FAN
disagrees with NTP’s conclusion that studies “with
[fluoride] exposures in ranges typically found in the
water distribution systems in the United States (i.e.,
approximately 0.03 to 1.5 ppm) …are inconsistent and
therefore unclear.’“
Question
3:
Why is the NTP statement (P 2 & 59), ”When
focusing on findings from studies with
exposures in
ranges typically found in the United States (i.e.,
approximately 0.03 to 1.5 ppm in drinking water, NHANES
(Jain 2017)) that can be evaluated for dose response,
effects on cognitive neurodevelopment are inconsistent,
and therefore unclear”
not the primary conclusion of the review? As I
will discuss in other questions/concerns, even that
equivocal conclusions has some serious problems.
“The
conclusion that fluoride is presumed to be a cognitive
neurodevelopmental hazard in children is based on the
consistency of the data; however, most lower
risk-of-bias studies observed effects with drinking
water concentrations above 1.5 mg/L. As noted above,
describing the effects at 1.5 mg/L or below, which is
more relevant to the exposures observed in the U.S.
population, including from community water fluoridation,
is more difficult”. (P 57)
As noted in Question 2d, the
information NTP used for the primary conclusion “fluoride
is presumed to be a cognitive neurodevelopmental hazard”
does not actually seem to be consistent with studies of
fluoride exposure levels near that experienced in
fluoridated communities worldwide.
========================================
Concern 4:
Individuals associated with the Green, et al. study have
made very public claims (referenced below) about their
opinion that ingestion of optimally fluoridated water is
as harmful as lead exposure. Those claims seem to
have been staged, and they appear to be supported by the
current NTP conclusion that “fluoride
is presumed to be a cognitive neurodevelopmental hazard”
– which was repeated ten times throughout the monograph under
review. As with all claims made by fluoridation
opponents to date (and the NTP conclusion), they are
presented without relevant context and are not a
complete or accurate representation of the actual
evidence. Specifically:
a) Unlike fluorine, lead has no
known beneficial function in human health – only harmful
effects have been identified. In contrast, over 70
years of evidence supports the scientific consensus that
optimal exposure to fluoride ions (in water, toothpaste,
etc.) reduces the risk of dental decay and related
health problems.
b) There is no safe exposure level
for lead while there is no consistent, quality evidence
(as noted in the review) that drinking optimally
fluoridated water causes harm – and a great deal of
quality evidence of beneficial effects.
c) There is no way that ingestion of
optimally fluoridated water could be “very similar to the effect size that’s seen with childhood exposure to
lead.” If that were true, it would be
expected that someone besides fluoridation opponents
would have noticed it in the huge body of relevant
evidence.
d) Fluoridation opponents have made
a blanket statement about an alleged similarity between
lead exposure and fluoride exposure with no context of
exposure levels. Harm from low levels of lead
exposure is not equivalent to harm from high exposure
levels to fluoride – any more than a claim that taking
vitamin supplements causes hypervitaminosis.
e) It is very easy to cause
confusion and fear among members of the public who don’t
have relevant science/health training or experience by
promoting blanket, out of context statements like
fluoride exposure is “actually
very similar to the effect size that’s seen with
childhood exposure to lead” or “fluoride
is presumed to be a cognitive neurodevelopmental hazard”
f) With lead exposure there is no
discussion about risks vs. benefits at any exposure
level because there are no known benefits, only risks of
harm. In contrast, with fluoridation, even if an
association was demonstrated of low fluoride exposure
and a small drop in IQ (or other neurological issue)
there would still need to be a discussion of any
potential risks against the well-established benefit.
Simply making out-of-context statements like fluoride
exposure is “actually
very similar to the effect size that’s seen with
childhood exposure to lead” or “fluoride is presumed to be a
cognitive neurodevelopmental hazard” is not
supportable by scientific principles.
Specific
Public Claims:
~>
According to Green (~27-30 minutes), the
strength of correlation of one of the important
regression lines in the Figure 3 graphs (apparently for
the Male/MUFC correlation) “explains 5% of the variance”
–– which would mean a
r2
value of 0.05 –– and was defended as statistically
important within the context of various factors that
might possibly influence IQ. She stated it “is
quite a big number. It is actually the same number we
see in the lead IQ studies…”
https://www.facebook.com/MedPageToday/videos/2396767130414029/
~> “In an editorial “Is Fluoride Potentially Neurotoxic?”
that ran with
Till’s study, David Bellinger, a professor of neurology
at Harvard Medical School and Boston Children’s
Hospital, wrote that ‘the hypothesis that fluoride is a
neurodevelopmental toxicant must now be given serious
consideration.” He told NPR: ‘It’s
actually very similar to the effect size that’s seen
with childhood exposure to lead.’”
https://www.buzzfeednews.com/article/nidhisubbaraman/fluoride-water-iq-kids-debate
https://www.npr.org/sections/health-shots/2019/08/19/752376080/can-maternal-fluoride-consumption-during-pregnancy-lower-childrens-intelligence
~> In a
podcast with the JAMA Pediatrics Editor and Chief
Dimitri Christakis and Frederick Rivara the following
claim was made (4:00 minutes in) “Mothers
who lived in fluoridated areas had higher fluoride
concentration in their urine and a higher fluoride
intake during their pregnancy than mothers who lived in
non-fluoridated areas, and there seemed to be an effect
on their kids’ IQ. Now this effect was only seen
in boys, where a 1 mg/L increase in the maternal urinary
fluoride concentration was associated with a 5-point
lower score on the boys’ IQ. An effect size which
is sizable.
Which is sizable, on a par with lead. And in
girls, they found a non-significant increase in their
IQ. The effect size is really quite large…”
https://edhub.ama-assn.org/jn-learning/audio-player/17802991
~> Two news stories reported, “Fluoride poses a greater risk
than NTP's draft report suggests, Chris Neurath,
research director for the Fluoride Action Network, told
the committee,
NTP's report consistently paid less
attention to studies that found low concentrations of
fluoride could be harmful, he said.
The
scientific evidence showing fluoride can harm children's
developing brains is as strong or stronger than was the
data that emerged in the 1990s—and faced fierce
criticism—showing low levels of lead were neurotoxic,
Neurath said.”
https://patch.com/new-york/levittown-ny/long-islanders-wisely-rejected-fluoridation
https://news.bloombergenvironment.com/environment-and-energy/public-trust-in-tap-water-may-hinge-on-fluoride-link-to-child-iq
Question 4a:
Do you agree with my concerns above about claims of an alleged similarity between lead exposure and harm and that of exposure to optimally fluoridated water? If not, why not, and what specific evidence can be provided to prove that claim?
Question
4b: Is it appropriate to finalize
and publish the “SYSTEMATIC REVIEW OF FLUORIDE EXPOSURE
AND NEURODEVELOPMENTAL AND COGNITIVE HEALTH EFFECTS”
current NTP conclusion that “fluoride is presumed to be a
cognitive neurodevelopmental hazard“ before all
criticisms of the current NTP review (and the studies
they are based on) knowing the anti-fluoridation
activists will immediately further distort any
conclusions and pronounce that science has validated
their opinions that fluoride is poison and community
water fluoridation should be banned???
========================================
Concern 5: There are
many extremely important, potential factors that can
significantly contribute to a child’s IQ. Some are
listed below, and most of them apparently were not
collected, analyzed and included in the Green, et al.
study (or in the other studies reviewed either.
Some of these important,
mostly ignored variables include:
a)
Parental IQ:
“IQ and education for both parents were statistically
correlated to child IQ. However, paternal IQ and
education were not significant after accounting for
maternal IQ effects.” (Meador, et al., Epilepsy Behav.
2011) “IQ correlations – father-child, 0.51;
mother-child, 0.55. So intelligence clearly has a
powerful genetic component.”(Intelligence and IQ,
Dr. C. George Boeree)
b)
Diet and nutrition of mothers
during pregnancy & Diet and nutrition of children after
birth: “After adjusting for maternal
education, socioeconomic status, the Home Observation
for Measurement of the Environment (HOME) score, and
total caloric intake, the good prenatal and childhood
nutrition indices predicted more favorable
neurodevelopment, while both poor nutrition indices
predicted poorer neurodevelopment. These associations
were stronger in prenatal than childhood models.” (Malin,
et al., Nutrients 2018)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115750/
c)
Birth weight and early-life
weight: “Within this cohort of
typically developing children, early-life weight status
was inversely associated with children's perceptual
reasoning and working memory scores and possibly with
full-scale intelligent quotient scores.” (Li, et
al., Obesity, 2018)
d)
Length of time breast-feeding:
“Breastfeeding duration of 1 month or shorter
compared with longer periods was associated with
approximately three points lower IQ… In conclusion, in
this large sample with high quality assessment of child
IQ, we found support of a beneficial association for
breast feeding with child IQ at 5 years of age, while
adjusting for maternal IQ and parental education, which
only few previous studies have been able to do.” (Strøm,
et al., BMJ Open 2019)
e)
Amount of time parents spent
with child: “Using a large
longitudinal British dataset, I show that paternal
involvement in childhood has positive associations with
offspring IQ at age 11, and offspring social mobility by
age 42, though not with numbers of grandchildren. For
IQ, there is an interaction between father's
socioeconomic status socioeconomic status (SES) and his
level of involvement, with high-SES fathers making more
difference to the child's IQ by their investment than
low-SES fathers do.” (Evolution and Human Behaviour,
2008)
f)
“Maternal education,
household income, parents’ skin color, duration of
breastfeeding, head circumference and number of siblings
were the most powerful predictors of low IQ at age six.
Of a broad set of potential social and biological
predictors explored those essentially social were the
most impactful ones, which could mean that a high
proportion of these children may require intervention.”
"Another major finding of this study is the effect of
growth, nutrition, and breastfeeding during the first
year of life on cognitive ability. Children who were
breastfed for a longer period were less likely to have
low IQ than those who were not breastfed." "Other
predictors of low IQ were smoking during pregnancy and
maternal perception of the child’s health."
(Camargo-Figuera, et al., BMC Pediatr.)
g)
Amount of time each child
spent in front of TV or playing electronic games:
“In multivariate models, being a third-born or more
child and watching television ≥1 h/day at 24 months were
negatively associated with all IQ scores…” (Plancoulaine,
et al., Sleep Med. 2017)
h)
Many other factors were
ignored that influence intelligence and cognitive
development in infants and young children:
that influence intelligence and cognitive development in
infants and young children, for example: Amount of time
each child spent outside playing; Amount of time each
child spent socializing with others; any environmental
stress, genetics, etc.
“The IQ of an
individual is multifactorial and is determined by a
multitude of factors. Nature and nuture work together in
determining human intelligence. Even though the genetic
susceptibility plays a crucial role on the IQ of the
individual, various modifiable environmental factors
like education, premature birth,
nutrition, pollution,
drug and alcohol abuse, mental illnesses,
and diseases can have an influence on an
individual’s IQ. These modifiable factors can reinforce
or weaken genetic susceptibility.” (Arun Oommen,
Journal of Neurology & Stroke, 2014)
If the Green, et al. study
had actually been designed and implemented to find a
legitimate, potential association between prenatal
exposure to low levels of fluoride, and IQ, then data on
most of these (and other) extremely critical factors
which have known negative effects on IQ and cognitive
development should have been collected and analyzed in
addition to the several factors mentioned in the report.
Question 5a: Without adjusting for a number of significant factors that contribute to IQ how can the NTP review Evaluation Team possibly conclude that “fluoride is presumed to be a cognitive neurodevelopmental hazard“? As discussed in other questions this is a particularly disturbing conclusion when made in the absence of exposure levels and other significant limitations.
Without considering many
possible factors that can have an important impact on a
child's IQ, why would any extremely low (boys-only)
potential association of IQ with low levels of exposure
to fluoride be of any value?
Question
5b: What is your assessment of
the criticisms of the Green, et al. study to date?
If any of them are legitimate and not addressed and
remain unresolved by the NTP review Evaluation Team, is
it appropriate to continue describing the assessment as
a highly unbiased, reliable study?
http://www.cyber-nook.com/water/FluoridationInformation-green.html
https://openparachute.wordpress.com/2019/09/25/biostatistical-problems-with-the-canadian-fluoride-iq-study/
I did some research and
discovered that both average income and average daily
temperature have a significant effect on IQ
with r2
values of 0.30 and 0.45 respectively. (Image 3
below)
In fact the correlation is about an order of magnitude
larger than most fluoride studies. From this
analysis it can be seen that a higher average daily
maximum temperature can be “presumed
to be a cognitive neurodevelopmental hazard“
while a higher average income confers a significant
cognitive neurodevelopmental benefit – of course a
higher IQ could confer a higher average income.
https://www.worlddata.info/iq-by-country.php
========================================
Concern 6:
The Risk-of-bias Heatmaps are an interesting feature of
the NTP review process – they add some color to what is
otherwise a black and white narrative. I am not a
statistician, and at first glance they seem to be
reasonable assessments.
However, as noted in my
previous Concern 2 and Question 2d, even from the
perspective of a scientist who is not specifically trained
or experienced in the complexities of statistical
analysis, I am able to understand that when scatter
graphs are presented that look like they were produced
by a shotgun blast (or a drunken monkey playing darts),
any presumed association would be extremely low, subject
to “adjustment” by any outliers and completely destroyed
by other un-considered or ignored significant
confounding factors. I have also read “How to Lie
With Statistics, and I have heard over the years of
various ways to manipulate a statistical analysis so
that statistically significant results are found.
I had no reason to delve into that realm until about
five years ago when I began examining claims made by
fluoridation opponents and other groups that are driven
to undermine various public health measures that are
based on the relevant scientific consensus. Since
then the frenetic dedication and creativity of those
groups has astounded me – not in a good way.
Concern about the Green, et
al. study motivated an unprecedented response from
thirty academics and professional experts from health
and dental institutions in the US, Canada, UK, Ireland,
and Australia to formally complain to the US National
Institute of Environmental Health Science (NEHS) about
the study.
https://openparachute.wordpress.com/2019/10/24/experts-complain-to-funding-body-about-quality-of-fluoride-iq-research/
The letter lists a number of problems with the Canadian
study. These include:
1.
Focusing on a subgroup analysis
amid “noisy data”:
2.
Modeling and variable anomalies:
3.
Lacking data on relevant factors:
4.
Omitting crucial findings:
5.
Using invalid measures to
determine individual exposures:
6.
Defining the final study group:
7.
Assessing the impact of fluoride
exposure:
8.
Reporting anomalies:
9.
Internal inconsistency of
outcomes:
10.
Overlooking research that conflicts with the
authors’ conclusions:
https://www.asdwa.org/wp-content/uploads/2019/10/NIEHSLetter10-23-19.pdf
https://mattjacob.s3-us-west-2.amazonaws.com/cwf/CADTH+Evaluation+of+Green+Study+(2019).pdf
I have carefully examined all
of the criticisms of the Green, et al. study submitted
by a number of statisticians based on claims that
various forms of statistical manipulation might account
for the published results of a presumed association
between fluoride exposure and IQ. It became
obvious that the same level of statistical evaluation
should be employed to assess the validity of study
conclusions from the other studies used by the NTP
review Evaluation Team to substantiate their claim that
“fluoride
is presumed to be a cognitive neurodevelopmental hazard“
– particularly if the claims are made in the context of
ingesting optimally fluoridated water.
http://www.cyber-nook.com/water/FluoridationInformation-green.html
I did not see any category in
the Risk-of-bias Heatmaps that evaluated the potential
statistical issues in the 10 concerns listed above or in
other criticisms like satisfying Hill’s Criteria of
Causality, limitations suggested in the CADTH appraisal, possible P Hacking, etc.
https://www.acsh.org/news/2019/08/19/no-fluoride-doesnt-lower-iq-it-fails-satisfy-hills-criteria-causality-14229
https://epidemiological.net/2019/09/23/the-hijacking-of-fluorine-18-998-part-three/
https://www.sciencemediacentre.org/expert-reaction-to-study-looking-at-maternal-exposure-to-fluoride-and-iq-in-children/
Question 6a: Why are there apparently no Risk-of-bias Heatmap categories for the numerous potential problems identified with the statistical analysis process in the Green, et al. study – and by association with the other reviewed studies?
Question 6b:
Will relevant new “statistical appropriateness/validity”
categories be added to the final NTP SYSTEMATIC REVIEW
OF FLUORIDE EXPOSURE AND NEURODEVELOPMENTAL AND
COGNITIVE HEALTH EFFECTS? If no, why not? If yes,
what specific potential manipulatory statistical tactics
would be considered?
Question
6c: Did the NTP review Evaluation
Team assess the Green, et al. study (and the others on
the Risk-of-bias Heatmaps) against any of the
statistical critiques presented above?
~> If so, which critiques were considered, which studies
were evaluated and what were the NTP review Evaluation
Team’s specific findings?
~> if not, why were the potentially serious study
limitations not addressed?
Question
6d: Will the NTP review
Evaluation Team publically address all of the specific
and extremely serious concerns of statisticians and
other relevant experts that have been presented against
the Green, et al. study – and by association, with all
of the other studies referenced in the NTP in the final
Monograph?
Question
6d: In the Review Monograph (P
8) the Evaluation Team states, “Unpublished data were eligible for inclusion provided the owner of the
data was willing to have the data made public and peer
reviewed.” Does this
statement apply to published studies like Green, et al.
where 30 experts have identified potentially significant
issues and are requesting the data be made public and
open to additional peer review. Understandably
(and thankfully), this is a rare situation, but if
inappropriate statistical methods have been utilized –
even unintentionally – to arrive at conclusions which
are not as published, it is critical to expose them.
========================================
Concern 7:
I understand that Friday, November 15 is the deadline
for acceptance of comments on the Fluoride Monograph and
that there is a significant volume of concerns,
information and questions.
Question 7:
Is it appropriate to close the collection of new data,
concerns, criticisms and opinions on Friday, November 15
before all of the relevant issues have been exposed and
adequately addressed?
A final communication sent Friday, November 15, 2019:
Attention: Project RSO Dr.
Ellen Mantus, Chair Dr. David Savitz, and the Peer
Reviewers of the NTP Draft Monograph on Systematic
Review of Fluoride Exposure and Neurodevelopmental and
Cognitive Health Effects.
Before the deadline for
comments on the NTP Draft Fluoride Monograph expires
tonight, I would like to respectfully (but urgently)
make a request. Even if my critiques of the
Monograph and the dozens of other excellent
assessments/suggestions I have read from scientists and
health care professionals with more direct knowledge and
experience than myself are not sufficient to
substantially change the current draft version of the
systematic review of the SYSTEMATIC REVIEW OF FLUORIDE
EXPOSURE AND NEURODEVELOPMENTAL AND COGNITIVE HEALTH
EFFECTS, please at least consider changing the
conclusion that “fluoride is presumed to be a
cognitive neurodevelopmental hazard to humans.”
As I noted in my previous
communications, the phrase “fluoride is presumed
to be a cognitive neurodevelopmental hazard to humans”
is used ten times in the review, and yet it is
completely out of context of any exposure levels.
It is not until several sentences later than
qualifications are admitted that, “When focusing on
findings from studies with exposures in ranges
typically found in the United States (i.e.,
approximately 0.03 to 1.5 ppm in drinking water, NHANES
(Jain 2017)) that can be evaluated for dose response,
effects on cognitive neurodevelopment are inconsistent,
and therefore unclear. ” And that conclusion
does not take into account any review of the studies
based on the comments and suggestions – many of which I
have read point to significant limitations and potential
biases that would remove even the “inconsistent, and
therefore unclear” conclusions.
It may be appropriate to make
the claim that “mercury is presumed to be a hazard to
humans”, or “lead is presumed to be a hazard to humans”,
or “disinfection byproducts are presumed to be a hazard
to humans”, or to label any element or chemical that is
known to have no beneficial health effects – and is
known to cause only harm.
However, it is not
appropriate to label a substance like fluoride ions that
have been presumed to have a beneficial effect on human
health at optimal exposure levels (0.7 ppm in drinking
water which is meant to be ingested or 1,500 ppm in
toothpaste which is not meant to be ingested) with a
blanket accusation that “fluoride is presumed to be a
cognitive neurodevelopmental hazard to humans”
– particularly when it appears the review team
conclusions don’t support that conclusion at levels
below 1.5 ppm.
That would be as irresponsible as making blanket statements like, “coffee and aspirin are presumed to be a neurological hazard to humans” or “water ingestion is presumed to cause death” or “vitamins are presumed to be harmful to health. All those statements are true if benefits the at lower, optimal levels are ignored and if, like the fluoride presumption, there is no mention of exposure levels
My suggestion is that, if the
concerns about the current Draft NTP Monograph are not
sufficient to significantly alter the conclusions, at
least modify the statement of presumption and modify
the 10 instances that claim “fluoride is presumed to be
a hazard” in the monograph to “Excessive
fluoride exposure (>1.5 ppm) is presumed to be a
cognitive neurodevelopmental hazard to humans.”
If that change is not made
and fluoride is presumed a hazard in the final document,
the fight to keep water fluoridated worldwide will get
even harder.
If that change is made, and a
fair context of the conclusions is presented, there will
be some ammunition to mitigate the constant onslaught of
individuals driven to remove fluoride from community
water.
--------------------------------------------------------------
Some examples from today of
how the current argument can be influencing public
opinion:
Dentists continue to
ignore fluoride’s effect on the brain
https://www.scoop.co.nz/stories/GE1911/S00057/dentists-continue-to-ignore-fluorides-effect-on-the-brain.htm
Federal Judge to Decide if
Fluoride-in-Water Case Goes to Trial
“The EPA says the health groups haven’t
made the case that flouride in drinking water poses an
unreasonable risk.
But the health advocates point
to a 2017 federal study that found increased levels of
fetal fluoride exposure linked to lower childhood IQ.
And a Canadian study reported in August that fluoride
exposure during pregnancy was associated with lower IQ
scores in children aged 3 to 4 years.
A September 2019 draft report by the National
Toxicology Program, which examined the Canadian
study and others, said that human studies show higher
fluoride exposure is associated with decreased IQ or
other cognitive impairments in children. [actually
the conclusion was ‘fluoride is presumed to be a
cognitive neurodevelopmental hazard’] However, it
added that studies with exposures in the range typically
found in U.S. tap water showed effects on cognitive
neurodevelopment were inconsistent, and therefore
unclear.”
https://news.bloombergenvironment.com/environment-and-energy/federal-judge-to-decide-if-fluoride-in-water-case-goes-to-trial
Respectfully, Randy Johnson, MS
biology
Image 1:
http://fluoridealert.org/content/bulletin_10-26-19/
Image 2:
Image 3:
https://www.worlddata.info/iq-by-country.php