Thursday, March 07, 2013

Prominent Toxicologist Opposes Fluoridation

Statement on the fluoridation of public drinking supplies by Professor C V Howard. MB. ChB. PhD. FSB. FRMS. FRCPath. 14/2/2013

1) I am a medically qualified toxico-pathologist and expert on effects of toxic substances on the fetus and infant during the developmental period of life. I am a Past President of the International Society of Doctors for the Environment, which is a World Health Organisation and United Nations recognised NGO representing some 30,000 medical doctors around the world. I have served on UK Government regulatory committees and am currently Professor of Bioimaging at the University of Ulster.  I served as an Expert Witness on fetal toxicology causation in the case of Castillo vs Dupont in Miami, Florida.

2) Pre-industrial levels of fluoride in the environment were very low. There are now many different sources of both therapeutic and pollutant sources of fluoride. The former can be taken, under informed consent, for dental health purposes. 

3) It is generally accepted that the predominant action of fluoride on dental enamel is a topical one and that there is little additional benefit from systemic administration (CDC, 1999).

4) The ‘one dose fits all’ method of administration to whole populations via the public drinking water supply is known to be deeply flawed. This particularly applies to the neonatal infant being fed formula milk, which is reconstituted using fluoridated tap water. In the latter case it is acknowledged overdosing is occurring. A baby drinking formula made up with fluoridated tap water at 1 ppm will get 250 times more fluoride than a breast-fed baby.

5) Breast milk contains very low levels of fluoride (0.004 ppm, NRC, 2006, p.40), even when the lactating mother has been administered fluoride. Though the serum level of fluoride increased, the breast milk level remained very low (Ekstrand, 1981, 1984)). It is my opinion that this is the result of a specific exclusion process that has evolved to protect the neonate from exposure to anything other than very low levels of fluoride during critical windows of development of a number of organs.

6) There is evidence of developmental neurotoxicity from exposure to fluoride, expressed as reduced IQ distributions in populations, when compared epidemiologically with populations with lower exposures. There now have been 36 studies (see the complete listing at that have found a lowered IQ associated with even modest exposure to fluoride. For example Xiang et al. (2003) found a threshold for IQ lowering at 1.9 ppm. Ding et al. (2010) have found a lowering of IQ in the range of 0.3 to 3 ppm. Moreover, they and other researchers, have reported a correlation between the extent of the IQ lowered and the level of fluoride exposure as measured in the urine.

7) Recently a team from Harvard University (Choi et al, 2012) reviewed 27 of these IQ studies using a meta-analysis. They found a remarkable consistency in the results even though they were derived from four different countries (China, India, Iran and Mexico). Of the 27 studies comparing villages with low levels of fluoride and with villages with modest to high levels of fluoride (0.88- 11.5 ppm), 26 revealed a lower IQ in the children from the “high” fluoride village. The mean difference was 7 IQ points, which from a population perspective is highly significant. Such a shift would reduce the number of geniuses in a large population by at least 50%, and approximately double the number of mentally handicapped.

8) The mechanism by which this IQ lowering could occur is not fully understood. However, direct toxicological action by fluoride on the developing nervous system is a biologically feasible likelihood. There have now been well over one hundred animal studies indicating that fluoride can cross the blood brain barrier and cause changes in the brain (see appendix 1 in the book “The Case Against Fluoride” by Connett, Beck and Micklem). Another mechanism is an indirect one, via disturbance of thyroid hormone metabolism, which should be considered (See chapter 8 of the National Research Council report Fluoride in Drinking Water: A Review of EPA’s standards, NRC, 2006, for a comprehensive review of fluoride’s interactions with the endocrine system). The finding that even variations in thyroxin levels within the maternal euthyroid (normal) range can subtly affect the IQ of offspring (Pop et al 1995, 1999) highlights the very critical role of the hormone in controlling normal neural development. The prior therapeutic use of F to reduce thyroid hormone levels in cases of thyrotoxicosis is well documented (Goldemberg, (1926, 1930, 1932); May (1935, 1937); Orlowski (1932) and Galletti and G. Joyet, (1958)).

9) There is evidence that the incidence of osteosarcoma, a frequently lethal bone cancer, increased in teenage boys in fluoridated versus non-fluoridated areas (Hoover et al., 1991); Cohn, 1992). These findings were greatly strengthened by a case-control study conducted at Harvard by Elise Bassin (Bassin et al., 2006).  Bassin found that young boys exposed to fluoridated water in their 6th, 7th and 8th years had a 5-7 fold risk of succumbing to osteosarcoma by the age of 20. At the time that this study was published Bassin’s thesis adviser, Chester Douglass promised in a letter (Douglass and Joshipura, 2006) that his larger study would refute her findings. However, Douglass’s study was finally published (Kim et al., 2011) failed to refute Bassin’s thesis. In other words we have a high quality – unrefuted - study, which indicates that fluoridation may actually be killing a few young men each year.

10) Given the above uncertainties concerning the causation of harm to human health through mandatory fluoridation of the public drinking water of whole populations, allied to the very dubious advantage for dental health of the practice, it is my considered opinion that on the balance of medical probabilities that there is a strong case for not considering the fluoridation of public drinking water.  This statement is made also in the light of ethical issues concerning a) the incidence of avoidable dental fluorosis in young people and b) the mass medication of a whole population without prior informed consent.

11) Statement on conflicts of interest. I have no commercial interests or research grants, current or past, concerning the fluoridation of drinking water. I hold no shares in any companies involved in water fluoridation. I have never received a fee for speaking on the topic of fluoridation.

Bassin, EB, Wypij, D,  Davis, DB, and Mittleman, MA. (2006). “Age-specific Fluoride
Exposure in Drinking Water and Osteosarcoma (United States),” Cancer Causes and
Control 17, no. 4 (May): 421–28.

CDC (1999). Centers for Disease Control and Prevention, “Achievements in Public Health,
1900–1999: Fluoridation of Drinking Water to Prevent Dental Caries,” Mortality and
Morbidity Weekly Review 48, no. 41 (October 22, 1999): 933–40,

CDC (2010). Beltrán-Aguilar ED, Barker L and Dye BA. Nov 2010, Prevalence and Severity of Dental Fluorosis in the United States, 199–2004 National Center for Health Satistics.
Choi, A.L., et al., Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis. Environ Health Perspect, 2012

Cohn, PD (1992). An Epidemiologic Report on Drinking Water and Fluoridation, New Jersey Department of Health, Environmental Health Service, November 8, 1992. Note:
The original title of this report was A Brief Report on the Association of Drinking Water
Fluoridation and the Incidence of Osteosarcoma Among Young Males. The word “osteosar-
coma” was deleted from the title soon after the report was released; http://fluoridealert

Connett, P., Beck, J. Micklem, H.S.  The Case Against Fluoride. Chelsea Green, Vermont, 2006.
Douglass, CW and Joshipura, K (2006). “Caution Needed in Fluoride and Osteosarcoma Study” (letter), Cancer Causes & Control 17, no. 4 (May 2006): 481–82.

 Ekstrand, J., Boreus, LO and P. de Chateau, P. (1981). No Evidence of Transfer of Fluoride from
Plasma to Breast Milk.  British Medical Journal 283, no. 6294: 761–62.

 Ekstrand, J., Spak,CJ, Falch, J. et al. (1984). Distribution of Fluoride to Human Breast 
Milk Following Intake of High Doses of Fluoride. Caries Research 18 (1):

Galletti P, and Joyet, G. (1958). Effect of Fluorine on Thyroidal Iodine Metabolism in
Hyperthyroidism. Journal of Clinical Endocrinology 18, no. 10: 1102–10.

 Goldemberg, L. (1930). Traitement de la Maladie de Basedow et de l’Hyperthyroidisme par le Fluor. La Presse Médicale 102: 1751.

Goldemberg, L. (1932).  Comment Agiraient-ils Therapeutiquement les Fluoers dans le Goitre Exopthalmique et dans L’Hyperthyroidisme. La Semana Médica 39: 1659.

Hoover, et al. (1991). U.S. Department of Health and Human Services, Review of Fluoride: Benefits and Risks,
Public Health Service, Washington, DC, February 1991,
ReviewofFluoride/ appendix E.

Kim FM, Hayes C, Williams PL, et al. (2011). An assessment of bone fluoride and osteosarcoma. J Dent Res. 2011. doi: 10.1177/002203451141882

May, W. (1935). Antagonismus Zwischen Jod und Fluor im Organismus. Klinische
Wochenschrift 14: 790–92.

May, W. (1937). Behandlung the Hyperthyreosen Einschliesslich des Schweren Genuinen
Morbus Basedow mit Fluor.  Klinische Wochenschrift 16: 562–64.

NRC (2006). National Research Council of the National Academies, Fluoride in Drinking Water: A Scientific Review of EPA’s Standards (Washington, DC: National Academies Press, 2006),

Orlowski, W. (1932). Sur la Valeur Therapeutique du Sang Animal du Bore et du Fluor dans la Maladie de Basedow.  La Presse Medicale 42: 836–37.

Pop VJ, Kuijpens JL, van Baar AL, Verkerk G, van Son MM, de Vijlder JJ, et al. Low maternal free thyroxine concentrations during early pregnancy are associated with impaired psychomotor development in infancy. Clinical Endocrinology 1999;50:149-55.
Pop V.J., de Vries E., van Baar A., Waelkens J.J., de Rooy H.A., Horsten M., et al. Maternal Thyroid Peroxidase Antibodies during Pregnancy: A marker of impaired Child development? Journal of Clinical Endocrinology and
References to the 25 IQ studies:
 (links to the references cited here can be accessed at )

Y. Chen, F. Han, Z. Zhou, et al., “Research on the Intellectual Development of Children in
High Fluoride Areas,” Fluoride 41, no. 2 (2008): 120–24, (originally published in 1991 in
Chinese Journal of Control of Endemic Diseases),

Ding Y, Gao Y, Sun H, Han H, Wang W, Ji X, Liu X, Sun D. (2010). The relationships between low levels of urine fluoride on children's intelligence, dental fluorosis in endemic fluorosis areas in Hulunbuir, Inner Mongolia, China. Journal of Hazardous Materials doi:10.1016/j.jhazmat.2010.12.097.

X. Guo, R. Wang, C. Cheng, et al., “A Preliminary Investigation of the IQs of 7–13 Year Old
Children from an Area with Coal Burning-Related Fluoride Poisoning,” Fluoride 41, no. 2
(2008): 125–28 (originally published in 1991 in Chinese Journal of Endemiology), http://www.

F. Hong, Y. Cao, D. Yang, and H. Wang, “Research on the Effects of Fluoride on Child
Intellectual Development Under Different Environmental Conditions,” Fluoride 41, no. 2
(2008): 156–60 (originally published in 2001 in Chinese Primary Health Care), http://www

X. S. Li, J. L. Zhi, and R.O. Gao, “Effect of Fluoride Exposure on Intelligence in Children,”
Fluoride 28, no. 4 (1995): 189–92,

Y. Li, X. Jing, D. Chen, L. Lin, and Z. Wang, “Effects of Endemic Fluoride Poisoning on the
Intellectual Development of Children in Baotou,” Fluoride 41, no. 2 (2008): 161–64 (origi-
nally published in 2003 in Chinese Journal of Public Health Management), http://www

F. F. Lin, Aihaiti, H. X. Zhao, et al., “The Relationship of a Low-Iodine and High-Fluoride
Environment to Subclinical Cretinism in Xinjiang,” Xinjiang Institute for Endemic
Disease Control and Research; Office of Leading Group for Endemic Disease Control
of Hetian Prefectural Committee of the Communist Party of China; and County Health
and Epidemic Prevention Station, Yutian, Xinjiang, Iodine Deficiency Disorder Newsletter 7,
(1991): 3,; also see

S. Liu, Y. Lu, Z. Sun, et al., “Report on the Intellectual Ability of Children Living in High-
Fluoride Water Areas,” Fluoride 41, no. 2 (2008): 144–47 (originally published in 2000 in
Chinese Journal of Control of Endemic Diseases),

Y. Lu, Z. R. Sun, L. N. Wu, et al., “Effect of High-Fluoride Water on Intelligence in
Children,” Fluoride 33, no. 2 (2000): 74–78,

Poureslami HR, et al. (2011). International Journal of Paediatric Dentistry 21(Suppl s1):47.

L. Qin, S. Huo, R. Chen, et al., “Using the Raven’s Standard Progressive Matrices to
Determine the Effects of the Level of Fluoride in Drinking Water on the Intellectual
Ability of School-Age Children,” Fluoride 41, no. 2 (2008): 115–19 (originally published in
1990 in Chinese Journal of the Control of Endemic Disease), http://www.fluorideresearch

D. Ren, K. Li, and D. Liu, “A Study of the Intellectual Ability of 8–14 Year-Old Children in
High Fluoride, Low Iodine Areas,” Fluoride 41, no. 4 (2008): 319–20 (originally published
in 1989 in Chinese Journal of Control of Endemic Diseases), http://www.fluorideresearch

D. Rocha-Amador, M. E. Navarro, L. Carrizales, et al., “Decreased Intelligence in Children
and Exposure to Fluoride and Arsenic in Drinking Water,” Cadernos de Saúde Pública 23,
suppl. 4 (2007): S579–87.

B. Seraj, M. Shahrabi, M. Falahzade, et al., “Effect of High Fluoride Concentration in
Drinking Water on Children’s Intelligence,” Journal of Dental Medicine 19, no. 2 (2007):
80–86. Note: English translation forwarded by lead author (B. Seraj, department of pediatric
dentistry, faculty of dentistry, Tehran University of Medical Sciences), http://fluoridealert

M. H. Trivedi, R. J. Verma, N. J. Chinoy, et al., “Effect of High Fluoride Water on Intelligence
of School Children in India,” Fluoride 40, no. 3 (2007): 178–83, http://www.fluoride

G. Wang, D. Yang, F. Jia, and H. Wang, “A Study of the IQ Levels of Four- to Seven-Year-Old
Children in High Fluoride Areas,” Fluoride 41, no. 4 (2008): 340–43 (originally published
in 1996 in Endemic Diseases Bulletin [China]),

S. Wang, H. Zhang, W. Fan, et al., “The Effects of Endemic Fluoride Poisoning Caused by
Coal Burning on the Physical Development and Intelligence of Children,” Fluoride 41,
no. 4 (2008): 344–48 (originally published in 2005 in Journal of Applied Clinical Pediatrics

S. X. Wang, Z. H. Wang, X. T. Cheng, et al., “Arsenic and Fluoride Exposure in Drinking
Water: Children’s IQ and Growth in Shanyin County, Shanxi Province, China,”
Environmental Health Perspectives 115, no. 4 (2007): 643–47,

Q. Xiang, Y. Liang, L. Chen, et al., “Effect of Fluoride in Drinking Water on Children’s
Intelligence,” Fluoride 36, no. 2 (2003): 84–94,
FJ2003_v36_n2_p84-94.pdf. Also see Q. Xiang, Y. Liang, M. Zhou, and H. Zang, “Blood
Lead of Children in Wamiao-Xinhuai Intelligence Study” (letter), Fluoride 36, no. 3 (2003):

L. B. Zhao, G. H. Liang, D. N. Zhang, and X. R. Wu, “Effect of High-Fluoride Water Supply
on Children’s Intelligence,” Fluoride 29, no. 4 (1996): 190–92,

The following five Chinese I.Q. studies have not yet been translated:

J. A. An, S. Z. Mei, A. P. Liu, et al., “Effect of High Level of Fluoride on Children’s Intelligence”
(article in Chinese), Zhong Guo Di Fang Bing Fang Zhi Za Zhi 7, no. 2 (1992): 93–94.

Z. X. Fan, H. X. Dai, A. M. Bai, et al., “Effect of High Fluoride Exposure on Children’s
In Intelligence” (article in Chinese), Huan Jing Yu Jian Kang Za Zhi 24, no. 10 (2007): 802–3.
Y. L. Xu, C. S. Lu, and X. N. Zhang, “Effect of Fluoride on Children’s Intelligence” (article in
Chinese), Di Fang Bing Tong Bao 9 (1994): 83–84.

L. M. Yao, Y. Deng, S. Y. Yang, et al., “Comparison of Children’s Health and Intelligence
Between the Fluorosis Area with Altering Water Source and Those without Altering Water
Source” (article in Chinese), Yu Fang Yi Xue Wen Xian Xin Xi 3, no. 1 (1997): 42–43.

J. W. Zhang, H. Yao, and Y. Chen, “Effect of High Level of Fluoride and Arsenium on
Children’s Intelligence” (article in Chinese), Zhong Guo Gong Gong Wei Sheng Xue Bao 17,
no. 2 (1998): 119.