Monday, April 5, 2010

Fluoridation, My Thoughts (Follow up to the weekly agenda posting)

(My html tags disappeared--so no links--sorry!)

I have studied this issue in some depth as a lay person, starting from when I was first elected to Council more than two years ago, and more extensively while on the EC, and now this week, as I have been preparing for this meeting. I have re-looked at all the information, particularly as I have received a couple more emails, on both sides of the issues, even today, and they continue to pour in.


1. It is complex.

2. It goes to the heart of our provision of something we need for our daily life and health: water.

3. It addresses the only instance of mass medication of the US population using our water supply, something that is almost impossible to avoid contact with.

4. It also engages issues of children's health and economic disparities.


FIRST, I have read information and evidence from all sides of this debate—both pro-fluoride and anti-fluoride, and people with a more nuanced or cautious stance. I believe that all sides actually want what is best for public health. I believe that all sides actually do care deeply about children’s health and are concerned about health care inequities in our community and our country due to income.

SECOND, some writers and speakers on both sides of the debate seem, to me, to regularly overstate their case and even engage in scare tactics that make it even harder to sort out the issues.

The people who are arguing against the current status quo are always particularly vulnerable to doing this, because when you're in the minority or arguing a “new” point, it's easy to feel one must "scream" to make the new concerns heard. And this tendency gets worse when those on the other side simply dismiss these folks as crazed, anti-science conspiracy theorists without considering the evidence. People are not crazy to be concerned with this substance.

On the other hand, the people arguing for the status quo also can feel threatened by the opposition, and sometimes engage in these tactics, also, and, in this case, most have not consulted the most recent evidence that has gathered in the past decade or so.

And both sides often ignore or downplay evidence that does not support their conclusions.

THIRD, I'm not a scientist. I regularly read scholarly materials from a variety of disciplines. I also know that science is complex, and that the process of drawing firm, broad-based policy conclusions from research is actually amazingly complex. I am still educating myself on this issue. And I’m pretty humble about it. I have wrestled with my current stance, which has evolved over the course of this past week.

SO: The most useful, recent document I have found is this one, a massive, 2006 National Research Council (NRC) review of the scientific literature, entitled "Fluoride in Drinking Water," The NRC is a scientific group appointed by the federal government to advise on science-related policy. Their job was narrow: to simply address whether the EPA's "maximum contaminant level" for fluoride, which is still set at 4 milligrams per liter, should be lowered. These scientists spent 3 years working through all the research done on fluoride since the last major study of fluoride and EPA standards, in 1993. The committee of twelve scientists did not address any other issue (including whether water should or should not be fluoridated), but they did ultimately agree that the current level of 4 is too high, and should be lowered, because there are concerns about elevated fluoride levels, predominantly from food and drink sources, that most of the scientists agreed could not simply be dismissed.


* Our water's fluoridated levels fall within the .7-1.2 mg/liters recommended by the EPA and the CDC for preventing cavities (which dentists now typically call “caries”).
* It is not expensive--it's around a couple thousand dollars/ year for the whole community.
* It is cheaper than any other means of transmitting fluoride to the community would be, and it is continuous, which, given the way fluoride works, it needs to be readily available, ideally about every 90 minutes.
* BUT cost has not really the central issue: community health is.
* Without adding fluoride to our water, our water would still have fluoride levels, I believe of about .4 mg/liters.
* And virtually all of us would be exposed to significant fluoride content from other foods and beverages.

Here's what I have gathered from the materials I've read, esp. the NRC:

* Fluoride occurs naturally in our environment, and is also a by-product of industrial processes.
* Fluoride does probably work to retard the growth of dental caries—i.e., it doesn't technically prevent cavities, but it likely slows the growth of caries if they are regularly exposed to fluoride, especially when they first appear at the molecular level. (This pro-fluoride leaning article from Wikipedia--yes, I know, Wikipedia, but it's well documented and serves my purposes here--explains the action of fluoride pretty clearly. AND The CDC’s webpage is a one stop shop for all things pro-fluoride.)
o NOTE: The Wikipedia article just cited DOES NOT pay adequate attention, in my opinion, to the legitimate concerns raised by the studies reviewed by the NRC panel in 2006, cited above and explained below. (Nor the York University panel cited below.)
o Here’s how the York University summarizes their findings: The best available evidence suggests that fluoridation of drinking water supplies does reduce caries prevalence, both as measured by the proportion of children who are caries free and by the the mean change in dmh/DMFT score. The studies were of moderate quality (level B) but of limited quantity. The degree to which caries is reduced, however, is not clear from the data available. The range of the mean difference in the proportion (%) of caries-free children is -5.0 to 64%, with a median of 14.6% (interquartile range 5.05, 22.1%). The range of mean change in dmft/DMFT score was from 0.5-4.4, median 2.25 teeth, (interquartile range 1.28, 3.63 teeth). It is estimated that a median of six people need to receive fluoridated water for one extra person to be caries-free (interquartile range of study NNTS 4, 9). The best available evidence from studies following withdrawal of water fluoridation indicates that caries prevalence increases, approaching the level of the low fluoride group. Again, however, the studies were of moderate quality (level B), and limited quantity. The estimates of effect could be biased due to poor adjustment for the effects of potential confounding factors.
* The CDC and the ADA accept that fluoride works NOT by being swallowed (even in infants), but by being present in the saliva which then washes around the teeth--the fluoride in your saliva is residue from the fluoride in drinking water, toothpaste, fluoride rinses, food, and other beverages that have been in your mouth--especially tea. It does NOT need to be swallowed, ingested to have its intended effect. It does NOT work significantly on pre-erupted teeth.
* Due to the potential problem of fluorosis (stains on permanent teeth and on the skeleton due to too much fluoride build up in the body), the CDC cautiously recommends infant formula should probably NOT be mixed using fluoridated water.
* (Tea, even made from distilled water, is naturally very high in fluoride, by the way--A March 2008 tea and fluoride study published in Food and Chemical Toxicology found up to 4.5, 1.8, and 0.5 mg/L fluoride in black, green and white teas, respectively, when brewed for 5 minutes--and there are even significant amounts in herbal teas. That means that a cup of strong black tea has higher than EPA MCL standard levels for tested water! So people who don't trust fluoride at all, should probably not drink tea.)
* This is why having fluoride in food and water seems to be such an inexpensive and effective way to retard the growth of cavities: because it's constantly available and can start to work when cavities are at their most miniscule. (This does mean that most of the fluoride we put in the water is kind of useless: most of it is flushed down our toilets and put on lawns and in pools.)

* HOWEVER, it should be noted that poverty and lack of access to timely and regular dental care, not fluoridation, is the best predictor of serious dental problems. This is true worldwide. Fluoride may offer some small help, but studies conducted in cities like Detroit that do fluoridate their water reveal that the problems for poor populations are not ever able to be addressed by fluoride alone. To have good teeth, people need good food, good dental care access, good dental hygiene, more than they need fluoride. So, it’s true that Xenia and Springfield do not fluoridate AND that both cities share in the serious poverty problem faced by our state and country. Both cities have populations with serious dental issues. Yet so do many cities that fluoridate and have significant poor populations. (The article by Dr. Connett, cited below the next bullet, includes more references to cities that fluoridate experiencing a “dental crisis,” the words used to describe Boston’s problems—where they have fluoridated for decades.)

o It's important that people not view fluoride in the water as a silver bullet or an "easy" way to get a substitute for real dental care to poorer people. It is not any kind of silver-bullet nor is it likely to serve as a social leveler in our unequal society.
o If there's a chance that poor children especially are even marginally benefited by a little extra fluoride in the water, at low cost, isn't that enough of a reason to keep fluoridating? That's the most serious question we need to address. Dr. Paul Connett, who came to speak in YS, at the request of the Environmental Commission argues that it doesn't and may leave them even more vulnerable to negative health impacts of fluoride. (I find his use of the word "toxic," however, to be loaded--it's one of my reservations about the work of his group.)

* It's also true that, so far as we currently know, there's no evidence that we need fluoride for any bodily functions. Excess is stored in the bones, and places like the pineal gland. It appears that for most people, at the levels we ingest in our water, fluoride does not seem to be harmful, but the studies are actually quite limited and the data is not very reliable in either direction. (See especially the York University review of the scientific literature, below).
* However, people with sensitivity to fluoride--people with renal (kidney) problems, for example, may be absorbing much more fluoride over a lifetime, and we do not adequately understand the effects of that exposure—both the NRC report and the York University report conclude.
* The fluoride in our water is probably not “a poison” at the levels we fluoridate, any more than tea made from distilled water, or raisins (which naturally have high levels of fluoride in them) are poisons, but at very high levels it would be toxic--like many things in our environment.

· HOWEVER, There are concerns about the sourcing of fluoride for municipal water, which is not subjected to ‘food grade’ processing (although it is subject to federal regulations), and is a by-product of industrial processes. The kind of fluoride that is typically used is fluorosilicic acid (or Hydrofluorosilicic acid), which is a by-product of super-phosphate manufacturing, industrial fertilizer. This is what we use. It does sound scary. It’s important to remember that these chemicals do have to be tested before they can be used in the drinking supply and must meet federal standards, and then our water is tested after it’s added. The fluorociliac acid does contain trace amounts of some impurities (silver and phosphorous, for example), but there is no lead or mercury. Critics charge that the studies done on fluoride are typically done on sodium fluoride, rather than these industrial acids and that these are not the same and may cause greater damage than the naturally occurring forms of fluoride.

o The most serious claim about this difference that I have seen is in this article from the International Journal of Environmental Science, which argues that when they ingest fluoride in this form children absorb lead more easily. I will quote from the abstract: “The two chemicals in question — fluosilicic acid and sodium silicofluoride — are toxins that, despite claims to the contrary, do not dissociate completely and change water chemistry when used under normal water treatment practices. As a result, water treatment with siliconfluorides apparently functions to increase the cellular uptake of lead. Data from lead screening of over 280,000 children in Massachusetts indicates that silicofluoride usage is associated with significant increases in average lead in children's blood as well as percentage of children with blood lead in excess of 10μg/dL. Consistent with the hypothesized role of silicofluorides as enhancing uptake of lead whatever the source of exposure, children are especially at risk for higher blood lead in those communities with more old housing or lead in excess of 15 ppb in first draw water samples where silicofluorides are also in use.Preliminary findings from county-level data in Georgia confirm that silicofluoride usage is associated with higher levels of lead in children's blood. In both Massachusetts and Georgia, moreover, behaviors associated with lead neurotoxicity are more frequent in communities using silicofluorides than in comparable localities that do not use these chemicals. Because there has been insufficient animal or human testing of silicofluoride treated water, further study of the effect of silicofluorides is needed to clarify the extent to which these chemicals are risk co-factors for lead uptake and the hazardous effects it produces.”

· Our water is regularly and carefully tested for some heavy metals, after the inclusion of fluoride, and it always falls well within EPA standards on those measures. (However, this very recent article from the New York Times suggests that we should be testing for a lot more substances and metals in our water than we currently are and that the testing requirements are far too lax, given what is in our environment today.)

* The NRC report cited above makes clear that while most people are not exposed to extremely high levels of fluoride, there is need for more research on the effects of high (and lower) levels of fluoride, exposure over time, on:
o Increased risk of bone breakage: "The best available study, from Finland, suggested an increased rate of hip fracture in populations exposed to fluoride at concentrations above 1.5 mg/L. However, this study alone is not sufficient to judge fracture risk for people exposed to fluoride at 2 mg/L. Thus, no conclusions could be drawn about fracture risk or safety at 2 mg/L."
o Alterations in the reproductive system: "A few human studies suggested that high concentrations of fluoride exposure might be associated with alterations in reproductive hormones, effects on fertility, and developmental outcomes, but design limitations make those studies insufficient for risk evaluation."
o Neurotoxcitiy / intelligence: "Animal and human studies of fluoride have been published reporting adverse cognitive and behavioral effects. A few epidemiologic studies of Chinese populations have reported IQ deficits in children exposed to fluoride at 2.5 to 4 mg/L in drinking water. Although the studies lacked sufficient detail for the committee to fully assess their quality and relevance to U.S. populations, the consistency of the results appears significant enough to warrant additional research on the effects of fluoride on intelligence. ... A few animal studies have reported alterations in the behavior of rodents after treatment with fluoride, but the committee did not find the changes to be substantial in magnitude. More compelling were studies on molecular, cellular, and anatomical changes in the nervous system found after fluoride exposure, suggesting that functional changes could occur. These changes might be subtle or seen only under certain physiological or environmental conditions. More research is needed to clarify the effect of fluoride on brain chemistry and function."
o Failures in the endocrine system / thyroid: "The chief endocrine effects of fluoride exposures in experimental animals and in humans include decreased thyroid function, increased calcitonin activity, increased parathyroid hormone activity, secondary hyperparathyroidism, impaired glucose tolerance, and possible effects on timing of sexual maturity. Some of these effects are associated with fluoride intake that is achievable at fluoride concentrations in drinking water of 4 mg/L or less, especially for young children or for individuals with high water intake. Many of the effects could be considered subclinical effects, meaning that they are not adverse health effects. However, recent work on borderline hormonal imbalances and endocrine-disrupting chemicals indicated that adverse health effects, or increased risks for developing adverse effects, might be associated with seemingly mild imbalances or perturbations in hormone concentrations. Further research is needed to explore these possibilities."
* Western European countries mostly do not fluoridate.

· A respected Canadian research group, similar to the NRC, that advises national and international governments and organizations on public policy, The Research and Discussion Group at York University, did an extensive review of all the scientific literature worldwide in 2000, and they found that the evidence for fluoridation was at best mixed, and that there was reason for concern, because the evidence at all levels was of a poor quality (there are no A-level studies). As they explained in 2003, urging people to read the whole report (I’ve read the executive summary):

“We were unable to discover any reliable good-quality evidence in the fluoridation literature world-wide. What evidence we found suggested that water fluoridation was likely to have a beneficial effect, but that the range could be anywhere from a substantial benefit to a slight disbenefit to children's teeth. This beneficial effect comes at the expense of an increase in the prevalence of fluorosis (mottled teeth). The quality of this evidence was poor. An association with water fluoride and other adverse effects such as cancer, bone fracture and Down's syndrome was not found. However, we felt that not enough was known because the quality of the evidence was poor. The evidence about reducing inequalities in dental health was of poor quality, contradictory and unreliable. Since the report was published in October 2000 there has been no other scientifically defensible review that would alter the findings of the York review. As emphasised in the report, only high-quality studies can fill in the gaps in knowledge about these and other aspects of fluoridation. Recourse to other evidence of a similar or lower level than that included in the York review, no matter how copious, cannot do this.”

* Worldwide, the rates of dental decay have fallen, regardless of fluoridation. This fact was particularly persuasive to the Environmental Commission, particularly when combined with concerns about health risks. When all this is further combined with the fact that poverty is the best predictor of tooth decay, it does appear that fluoride’s role in dental health has often been overstated, even by respected authorities.
* Dr. Katherine Theissen, one of the 12 scientists on the NRC panel, argues, here, that the NRC findings can and should be considered when communities are looking at fluoridating water, and she summarizes her concerns. She concludes that fluoridation is not necessary and may be a matter of concern, especially related to the thyroid and pineal gland.
* NOTE: Dr. Theissen was already a fluoride skeptic before participating in the report, as she is quoted in earlier documents on the Fluroide Action Network webpages, but her tone is always careful and scientific. Indeed, she has a powerpoint presentation, which is linked to this interview with her on the FAN pages, about the potential link between elevated levels of fluoride—even mildly elevated—on the linked modern ailments such as hypothyroidism, obesity, depression, children’s lower ages of puberty, and reduced levels of calcium and iodine in American systems, that makes a very strong case that we should be concerned about the levels of fluoride that we are ingesting.)
* Here is a redaction of an article from Scientific American, entitled "Second Thoughts on Fluoridation" which quotes others from the committee, particularly by Dr. John Doull, professor emeritus of pharmacology and toxicology at the University of Kansas Medical Center, who chaired the NRC committee: “The thyroid changes do worry me. There are some things there that need to be explored"....."What the committee found is that we’ve gone with the status quo regarding fluoride for many years—for too long, really—and now we need to take a fresh look,” Doull says. “In the scientific community, people tend to think this is settled. I mean, when the U.S. surgeon general comes out and says this is one of the 10 greatest achievements of the 20th century, that’s a hard hurdle to get over. But when we looked at the studies that have been done, we found that many of these questions are unsettled and we have much less information than we should, considering how long this [fluoridation] has been going on. I think that’s why fluoridation is still being challenged so many years after it began. In the face of ignorance, controversy is rampant.” [NOTE: The redaction was made by the Fluoride Action Network, which is opposed to fluoridation. You can, however, read the beginning of the article, and purchase the entire article here--and it does seem to correspond in tone to the redaction provided by the FAN.]

I have been on all sides of this issue:

* I began assuming that only crazy John-Birchers were opposed to fluoridation. I had seen Stanley Kubrick’s film, Dr. Strangelove, and I thought concerns were on the level of the flat-earth society or the people who think the moon landing was faked.
* When I started researching, I came to be sympathetic to concerns raised by those opposed to fluoridation, particularly the issue of mass medication and concerns for people who may have elevated sensitivity to fluoride.
* Even this week, however, I was ready to reverse my stance, simply because of that basic fact that the studies I have read do indicate that fluoride works to reduce cavities.
* Truth in advertising: I have hypothyroidism, which is one of the conditions that may be connected to high levels of fluoride. (But I love tea and have a hard time not drinking tea!) Moreover, it’s likely that an even stronger case could be made that the chlorides in the water may have the same or worse effect on my thyroid, displacing iodines, and we cannot get rid of chlorides at this time, and have our water be cost effective.
* I understand, but was put off BOTH by the lack of knowledge of our local health department when they discussed this issue in a public forum last fall, AND by the lack of nuance in the arguments of those opposed to fluoridation, which often exaggerate the certainty of any links between fluoride and ill-health effects.
* However, many serious, well-trained scientists have examined the evidence closely and have seriously begun to reconsider the massive use of fluoridation in the United States and other English speaking countries. I agree with these scientists.


* The CDC and majority of health-care officials conclude that fluoride is, as a TOPICAL agent, beneficial for developing children’s teeth and probably adult teeth, but we do not need to ingest it.
* We need to be especially concerned about the hours that most village children are in school, especially following lunch, which are critical times for caries to develop; fluoride from the water fountains is likely preventing the growth of cavities on some of their teeth. This may be preventing cavities for village children each year, and I am concerned about that.
* The difference between the “naturally” occurring fluoride in our water and the amount we add is fairly small—from .4 to .7-1 mg/l (we have typically been at about 1 mg/l). People should not exaggerate this amount or the difference it will have on overall health, in either direction. Moreover, the awareness that fluoride is so widely found in our environment, is naturally found in water, and is a part of foods and beverages like tea that have been drunk in significant quantities for thousands of years, makes me very skeptical of the claim that fluoride itself is the toxin that some strive to paint it as being.
* I do not believe fluoride in the water is as important a source of fluoride today as it has sometimes been represented—both due to fluoride’s prevalence in normal foods and beverages and due to toothpastes, rinses, dental treatments, etc. The most important things for good dental health seem to be: a good diet, good oral hygiene, regular access to dental care.
* While fluoridated drinking water has been an inexpensive way of helping village teeth, it is a very inefficient mode of delivery. Most of it goes down the toilet, through our washing machines and dishwashers, or into our gardens and lawns.
* We do not medicate people using the water supply for any other purpose. Many countries—97% of Western Europe—have rejected fluoridation for that reason, because people cannot consent to it when it is in their water supply.
* There is some significant evidence that infants should not ingest fluoridated water, and that ingestion of the form of the fluoride we are adding may be harmful to any children who are exposed to lead, and that there is also an under-researched possibility that higher levels of ingested fluoride are affecting their maturity rates and metabolism.
* These concerns about the industrial sourcing and type of the fluoride and the difference that may make on poor children’s health—along with the other potential risk issues—makes me concerned about this mode of delivering the probably good benefits of fluoride to our village children’s teeth.


* That we should practice the stop adding fluoride to the water.
* We should have a dialogue about this issue with the school. If we make this change, we may need to urge additional dental hygiene in schools so that children whose parents want fluoride can easily, for example, use a fluoridated mouth rinse after lunch.
o Perhaps we could budget the money we currently spend on fluoride for fluoridated rinses in all the schools—in many locations within each building—and dental hygiene education programs.
* Persons with significant health problems, especially serious renal problems and others who believe they are sensitive to fluorides, chlorides and other elements in small quantities should probably still drink filtered or distilled waters.
* If my colleagues on Council disagree, and we decide to keep with the standard guidelines of the CDC, we should use the lowest amount possible, or .7mg/l.

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