Dear All,

Early today I started off with the intention of transcribing the panel discussion on the relevance of the NRC report to water fluoridation. It has not been an easy task. The sound quality was not always good, and I had to keep listening to the same passages over and over again to get an accurate version. After most of the day, I have only been able to transcribe the reponse of the NRC panel members to the first - but key - question: Did the NRC panel members feel that, contrary to assertions by the ADA, the CDC, the AWWA and even the chairman of the panel, Dr. John Doull himself, that the NRC report was relevant to water fluoridation?

Below are the key exerpts from the discussion of that question.

This discussion, chaired by Paul Connett, featured three members of the NRC panel (Dr. Hardy Limeback, Dr. Kathleen Thiessen and Dr. Bob Isaacson) as well as Dr. Bill Hirzy; Dr. Albert Burgstahler; Dr. Donald Taves and Chris Neurath, of the FAN research Team.

The discussion was preceded by a clip from a videotaped recording of the June 20 meeting of the Palm Beach County Commissioners (Florida) who met to reconsider the recommendation of County Administrator Bob Weisman to halt fluoridation in the light of the NRC report and the response from Dr. Jean Malecki of the County Health department who presented arguments why it should continue.

Paul Connett, maintaining that the only way that the CDC et al. can argue their position is by confusing concentration with dose, gave a toxicology 101 lesson on the difference between the three different ways that toxicologists gauge exposure to a toxic substance:

1) concentration in water measured in milligrams per liter;

2) dose in terms of milligrams per day (concentration in mg/liter times the number of liters of water consumed) and

3) dosage in terms of milligrams per kilogram bodyweight per day.

The conversion to dosage is critically important when one is extrapolating from health effects in adults, with large bodyweight, to children, with low bodyweights. This is why a dose of aspirin may be safe for an adult, but dangerous for a baby.

Chris Neurath then made a few more comments on the exposure analysis contained in Chapter 2 of the NRC report and indicated that certain subsets of the population are getting higher than currently considered safe dosages (based upon the current MCLG) simply from drinking large quantities of water at 1 ppm.

Connett: Starting with our three panel members…You have spent three years reviewing this only to have the CDC within 6 days of the publication of your report say that it wan’t relevant to water fluoridation. Do you think your report was relevant to fluoridation?

Limeback: I think we have to address the fact that they are lying to us and how we address their lies (applause) … My biggest frustration was listening to the webcast (on March 22, 2006, PC)…When John Doull, started off - as our committee chair - saying that we accept that water fluoridation is beneficial, we did not look at it, that really burned me up (Hardy used a more graphic term, PC) because even though we were charged only to look at 4 ppm or 2 ppm, we have clearly here documentation of  study after study showing that dosage is important for fluorosis and all kinds of things. Dosage is important and yet he then represented our committee falsely, nationally.

Connett: And this chairperson - Dr. Doull -  is an author of one of the leading textbooks on toxicology. He is saying (in effect) he doesn’t know the difference between concentration, dose and dosage - give me a break, of course he knows the difference. Kathy, your response. Is the report relevant to water fluoridation?

Thiessen:   Yes, that’s the short answer.  Let me say several things. Ideally, we would have been permitted to look at the whole issue of what are the toxic effects of fluoride; what ranges of exposure do they occur at, and what are the ranges of exposures experienced. Many parts of this report were written with that in mind, the exposure chapter was written with that in mind and some other chapters were. Some other chapters were written (with this question in mind, PC): is it safe or not safe at 4 mg per liter? That’s why there are some differences in the report.

Soon after it came out, I wrote Dan Stockin a letter (attached below, PC) some of you may have seen it. Is it relevant to water fluoridation? Yes.  Certainly, we say on page 13 in the pre-publication version, “As noted earlier this report does not evaluate or make judgements about the benefits, safety or advocacy of artificial water fluoridation. That practice is reviewed only in terms of being a source of exposure to fluoride.”

 We worked very hard to keep statements assuming benefits or safety - whatever - out of that and this took several rounds but we kept them out. But certainly the exposure chapter considers fluoride from all sources, including drinking water, including whatever the source of the fluoride in the drinking water, so it is certainly relevant with respect to the exposure. Many of the health effects discussed in there include exposures at or around 1 milligram/liter or they include exposures at ranges equivalent to those experienced by people on fluoridated water.

What I tried to do in chapter 8 (on the endocrine system) is to put the studies in terms of an estimated exposure in milligrams per kilogram per day, because that is the standard way to do these things, to make comparisons. For that chapter admittedly some of those estimates were rough because the information wasn’t complete in the papers, but we did the best we could do. But at least you have a way to make comparisons.

Many of the studies in that chapter (chapter 8, PC), Bob’s chapter (Chapter 7 on the brain, PC), Elise Bassin’s study (on osteosarcoma, PC) and some of the other ones in the cancer chapter, looked at exposure to fluoridated water or water at around 1 milligram per liter, so those are certainly all relevant.

I think some of the strengths of the report: we had 12 people who agreed unanimously that 4 milligram per liter was not safe, that 2 milligrams per liter was not safe. That goes a long way. That was based on the health effects that have traditionally been associated wtih fluoride and even the public health sorts of people admit to being caused by fluoride and that’s the dental and skeletal fluorosis - not all of them would have liked the bone fracture stuff in there -  but at least these are things that have been associated with fluoride exposure for a long time. Many of the other things in here (pointing to the web version of the NRC report, PC) are new- previous reviews have dismissed them out of hand or said they didn’t count … We got them in here… Because the exposure ranges for some of these effects are reached by some people on fluoridated water, they are wrong (to say it is not relevant to fluoridation, PC)…

We did a lot of work on groups of people who consume a lot of water. .. (we found) that the water intakes for people with diabetes insipidus - that’s not diabetes mellatus - can be huge. It is a small subset of the population but the EPA guidelines are supposed to protect everybody.

Dan I don’t have a copy of the letter I sent to you but there may be some other things in there which are relevant to water fluoridation (see copy of letter to Dan Stockin below, PC).

Isaacson:  I have been bewildered lately. I keep coming back to the origins of our committee - that’s where my bewilderment started. I think the charge to the committee was contradictory in some ways… I was surprised by the chairman in many regards..I think that the chairman was really dedicated to a threshold concept and  believed that there were levels which would be without  effect… in most cases I do not find any basis for (this) belief.

I was also a little bit surrpised about the composition of the committee which varied on a number of dimensions, with some people with dedicated positions before the meeting one way or another. I remember the meeting where we decided that we had to have Hardy here on the committee. Do you remember that? (question to Kathleen Thiessen) Oh yes. He was a true blessing on the committee. But I was bewildered that we had to come up with this through the committee itself. At any rate there were a lot of mysteries on how it operated.

The summary also bewildered me a bit, when I read that.  The line that (paraphrasing) “there is no question that fluoride was wonderful for the prevention of  cavities” - that line is in here (the March 22 web version, PC).   I pray to God it is not in the published version (hard copy, bound text, PC). I called Susan Martell  - she is the administrative coordinator and somebody nominated her for the Nobel prize for peace (laughter) and I think everyone seconded the motion - I said to her that “the peace will end if that line is in the published version.” We will wait and see…

So at any rate,  my advice to people who read it (when the published report comes out), is read the chapters and not the introduction and not the summary! Whatever you do.

1) Several (many) of the NRC panel members had little idea what they were getting into. They had no idea of the volume of work involved - nor the politics. By all accounts it was a long and harrowing experience.

2) The NAS ran out of the money alloted to this review by the EPA and had to put its own resources into completing the task.

3) The printing of the bound version of the final report has been delayed through lack of funds.

4) Later in the discussion the panel members responded to a letter submitted by Dr. Bob Carton (see below). Dr. Carton was working at the EPA when the 1985 MCLG was determined and is on record - and has produced evidence to show - that it was fraudulently derived. As you will see he is dismayed that the issue is now back in the hands of the EPA without a firm recommendation being made as to what a scientifically based MCLG should be.

5) During our disucssions both Hardy and Bob advocated an MCLG of zero, and Kathy provided a number of margin of safety factors which would have resulted in a MCLG well below 1 ppm.

6) While several people were in favor of a minority report (presumably offering a value for what they felt a new MCLG should be) this was rejected for strategic reasons. It was felt that agencies like the CDC would have hived off the part that they wanted, and that fluoridation proponents would have spun off their own minority report further obfuscating the overall findings. Hardy, Bob and Kathy all stressed that the important thing was that they achieved unanimity in the fact that neither the 2 nor the 4 ppm standards were protective of health; that unlike all previous reviews they had not dismissed the possibility that fluoride causes cancer, and that both the exposure analysis and several of the chapters had put enough solid scientific evidence on the table to produce a MCLG less than 1 ppm, if a standard regulatory risk assessment is conducted.

If I might add my own feelings on this: if the US EPA is forced to do an honest job (that’s a huge “if” which is going to keep us occupied for some time), they cannot be accused of having an anti-fluoridation bias, which might well have happened if say Hardy had led the charge for an MCLG of zero in a minority report.

In short the NRC panel has given the EPA the science. If the EPA joins the dots, the MCLG will end up less than 1 ppm and water fluoridation is over.

Paul Connett

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May 2, 2006

Daniel G. Stockin, MPH
Senior Operations Officer
The Lillie Center, Inc.
P.O. Box 1951
Brentwood, TN 37024

Dear Mr. Stockin,

Thank you for your interest in the recent National Research Council report on the toxicology of fluoride; as you know, I had the privilege of serving on the committee that prepared this report.  As a resident of Tennessee for 25 years, I appreciate your concern regarding the significance of the NRC report for water districts in Tennessee that are evaluating the safety and desirability of starting or continuing water fluoridation.

As you are aware, the NRC report did not evaluate the safety or benefits of water fluoridation, which were outside the scope of our committee’s assignment.  However, we also did not say that the practice of fluoridation is safe or that fluoride concentrations in water of 0.7-1.2 mg/L are safe-we did not evaluate that.  We did specifically address the safety of the Maximum Contaminant Level Goal (MCLG) of 4 mg/L, and we concluded, unanimously, that the MCLG is not protective of human health.  We said that the MCLG should be lowered, but we did not derive or suggest a new value for the MCLG.

Our conclusion that the MCLG of 4 mg/L is not protective was based largely on health effects that have long been considered specific to fluoride and significant enough to warrant protection, namely dental fluorosis and skeletal fluorosis.  We parted ways with previous reviews of fluoride by saying that severe dental fluorosis is an adverse health effect, not merely a cosmetic effect, that stage II as well as stage III skeletal fluorosis is an adverse health effect, and that a fluoride concentration of 4 mg/L is likely not protective with respect to an increased risk of bone fracture.  We indicated that at 2 or 4 mg/L, bone fluoride concentrations can reach the ranges historically associated with stage II and III skeletal fluorosis.  We were not able to rule out a carcinogenic effect of fluoride.  We reported that fluoride exposure is plausibly associated with a number of other health effects, including neurotoxicity, gastrointestinal problems, and endocrine problems, and that even though these effects are not necessarily specific to fluoride exposure, the associations cannot be ruled out and need further study.

For dental fluorosis, skeletal fluorosis, and risk of bone fracture, the committee considered studies in which populations were exposed to concentrations of fluoride in drinking water of around 4 mg/L; because there were sufficient studies at the exposure level of interest, we did not examine the whole range of possible fluoride exposures.  From those studies we concluded that 4 mg/L is not protective of those effects; only when the fluoride concentration in water is below 2 mg/L does the prevalence of severe dental fluorosis approach zero.  For some of the other health effects mentioned above, the committee examined studies over a wider range of exposures, depending on what information was available.  Some of those studies do include exposure levels that would be associated with water fluoride concentrations of around 1 mg/L.  The committee also provided a very thorough analysis of overall fluoride exposures in the U.S., which are largely driven by drinking water and beverages made with tap water.  We identified population subgroups who are at higher risk than usual of problems due to fluoride exposure, due to factors such as very high water consumption rates or increased retention of fluoride in the body.

I personally feel that the NRC report is relevant to many aspects of the water fluoridation debate, even though the committee did not directly address water fluoridation, in terms of either risks or benefits.  For instance, the report discusses the wide range of drinking water intake among members of the population, which means that groups with different fluoride concentrations in their drinking water may still have overlapping distributions of individual fluoride exposure.  In other words, the range of individual fluoride exposures at 1 mg/L will overlap the range of individual exposures at 2 mg/L or even 4 mg/L.  Thus, even without consideration of differences in individual susceptibility to various effects, the margin of safety between 1 and 4 mg/L is very low.  The report also discusses a number of health effects plausibly associated with fluoride exposure that should be considered in any future risk assessment for fluoride, besides the effects that have historically been attributed to fluoride.  Several issues pertaining to use of silicofluorides in municipal water are brought up, although it was outside the committee’s scope to address them in detail.  Recent information provided on the relationship between outdoor temperatures and drinking water consumption suggests that the historical guidelines for setting water fluoride levels should be revisited.  The report attempts to draw together much of what is known about the effects of fluoride exposure on human health and to identify the sizeable areas that are still not fully understood, for example, the molecular mechanisms by which fluoride exerts its effects.

I encourage you to read the report yourself, and to encourage your contacts at the various water districts to read it.  I hope that you and your contacts will feel free to call me or send me an e-mail if I can be of any further help to you.

Sincerely,

Kathleen M. Thiessen, Ph.D.
Senior Scientist
(865) 483-6111

kmt@senes.com
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Here is my summary of the deficiencies of the NRC report:

Regarding the March NRC report, it is obvious that a lot of honest effort went into this report and major breakthroughs have occurred. The members who fought for change should be congratulated.

Nevertheless, the report has serious problems:

Regarding Point #1: You can argue that the committee did not understand the requirements of the SDWA because EPA misled them in giving them their charge.  Transcripts of meetings between EPA and the committee prepared by FAN, show that EPA did indeed mislead the committee. However, the committee itself could have asked to see the exact wording of the law. They also should have examined the controversy surrounding the 1985 standard. The paper by myself and Bill Hirzy presented to the NAEP in 1998 at their annual conference is readily available on the web and should have been accessed by the committee.  Referenced in that paper is the  amicus brief prepared by the EPA professionals’ union specifically explaining the requirements of the law. The brief is also available on the web.

Point #2: As stated in the report, the committee was charged with evaluating the scientific basis for the MCLG established in 1985.   This means evaluating the scientific literature available to EPA in 1985 and up to the present time, and making an independent judgment of a safe level.  If you determine the number EPA came up with is not valid, the obvious question then becomes: what is valid? Once again EPA misdirected the committee by instructing them not to make their own determination of an MCLG. Why not? What were they afraid of?

If you apply the proper criteria required by the law and you independently determine your own safe level, this is some of what you can conclude: moderate dental fluorosis and Stage I skeletal fluorosis become adverse health effects. Any margin of safety puts the safe level below the levels of water fluoridation.  Since bone fractures were found to occur at 1.5 mg/l, the level required to protect against bone fractures drops below fluoridation levels. Depression of thyroid function is another probable health effect of fluoride.  Since effect levels are found as low as 0.7 mg/day for iodine deficient individuals, a safe level of zero is probably appropriate considering the amount of fluoride already received from sources other than drinking water.  A safe level of zero is also appropriate considering fluorides effects on the brain, especially in combination with aluminum. 

As stated by Dr. Thiessen in an email to me, “We endeavored to provide a solid information basis for the conclusions that need to be drawn by EPA and others.” I believe she is correct. The information is there. It is unfortunate that the most important conclusion the committee could have made was absent and the protective nature of the Safe Drinking Water Act was not applied properly. The determination of a safe level is now, once again, in the hands of politicians.

Best of luck on your conference. Pressing family matters prevent me from being there.

Congratulations on getting Ralph Nader’s support.

Bob