The Irish Health Research Board (HRB) in their recent review say that they found no definite evidence that community water fluoridation has negative health effects. Yet remarkably, and extraordinarly, the review did not in any way assess the exposure of the Irish population to fluoride; including the contribution of water fluoridation, food or beverage consumption, medicines or occupational exposures to fluoride from major industries that are known to be significant sources of fluoride such as computer manufacturing, aluminium processing, coal fired electricity generation, chemicals industry, cement, brick, glass or fertilizer manufacturing all of which have large workforces in Ireland. From a risk management perspective there is only one accurate way to access exposure and therefore risk, and that is to use established biomarkers of fluoride exposure by measuring the fluoride content in human blood, urine or bone, as well as measuring the fluoride content in commonly consumed beverages, foods as prepared with fluoridated water and to determine the exposure of the population to fluoride releasing medications that are commonly prescribed in Ireland. For engineers and scientists the concept of cumulative exposure is well understood, as it is applied in environmental, flood and pollution risk management and impact assessment. However, when its comes to the consumption of a known and established bio-accumulative toxin that is deliberately added to the water supply, it appears that the rigours of scientific assessment do not apply. In the case of the HRB review not one of these most basic tasks were undertaken.

In addition, the review while examining the literature on fluoride and neurological disease somehow managed to exclude the recently published study in the Journal Environmental Health, titled “Exposure to fluoridated water and attention deficit hyperactivity disorder prevalence among children and adolescents in the United States: an ecological association”. After controlling for socioeconomic status this study empirically demonstrated a direct association between more widespread exposure to fluoridated water and increased ADHD prevalence in U.S. children and adolescents [1]. This large scale ecological study, the first of its kind to investigate this association, was published the same week as the study by Peckham and associates who also found a significant association between water fluoridation and hypothyroidism disorders in the UK [2]. The latter study was included in the HRB review but the former was not? Why not?

As for the prevalence of thyroid disorders in Ireland, we must assume that the HRB are aware that the third most popular prescribed drug in Ireland is for the treatment of hypothyroid disorders [3]. From the sheer number of prescriptions and the normal prescription patterns for this drug, the data suggests that almost 10% of the Irish population suffer from hypothyroid disorders. This would indicate that Ireland has the highest prevalence of thyroid disorders in the developed world and would agree with the findings of Peckham and associates that water fluoridation was associated with a 60% increase in thyroid disorders among the population.

Overall, their desk based review entirely excluded the published literature which has found that many common medications can cause fluoride intoxication. This is a matter of significant public health concern, as the European Food Safety Authority noted that medications can contribute over 75% of the daily fluoride intake for infants alone [4]. So did the HRB review access fluoride intake from medications? No they did not.

Neither did the HRB review determine the fluoride intake and exposure from tea in Ireland, which is by far the most significant dietary intake source of fluoride for the Irish population. Over 60 published studies have been published internationally which have found excessive concentrations of fluoride in tea, yet remarkable not a single study has every been published in Ireland documenting the fluoride exposure from tea. As the worlds largest consumer of tea and with mandatory water fluoridation this omission is simply extraordinary. So did the Health Research board measure the fluoride content in tea products sold in Ireland? No they did not.

In fact, tea as a source of fluoride was only noted in their report as it was previously documented by myself in correspondence almost two years ago to the Chief Medical Officer, Minister for Health, Minister for Food and Agriculture among others, where I warned about public safety from excessive fluoride exposure and to which I have received neither a reply nor acknowledgement. Despite this, the HRB review could only conclude without actually testing tea products for fluoride content that “tea leaves contain proportionally higher levels of fluoride than CWF water that is used to make it”. This statement reflects a gross misrepresentation of the facts. Tea contains substantially higher concentrations of fluoride than CWF.

In 2006, the National Research Council of the United States (NRC) stated that in the UK consumers can ingest 9mg per day of fluoride from tea drinking alone and that making tea with fluoridated water contributes to excess fluoride intake and the risk of chronic disease. Furthermore, the NRC (2006) reported that consumption of just half a cup of brewed tea with an average fluoride concentration of 3.3 mg/L would equal the total background intake of fluoride from all food sources [5]. Moreover, in 2008, the Department of Public Health in Taiwan conducted a risk assessment on fluoride exposure from tea drinking measuring the fluoride content in over fifty specimens of tea using de-ionized water. The concentration of fluoride in the majority of tea samples was found to exceed 4 mg/L [6]. The authors found that elderly persons, who generally consume greater quantities of tea, would exceed the Acceptable Daily Intake (ADI) for fluoride from tea drinking and concluded that caution should be undertaken in considering fluoridation of water in Taiwan in order to avoid side effects. Drinking water is not fluoridated in Taiwan, but more importantly, per capita consumption of tea in Ireland is significantly higher than Taiwan.

The HRB must clearly be aware, that Ireland has the highest per capita consumption of tea in the world, 17% higher than the UK, 14 fold higher than the United States and over 40 fold higher than countries such as Spain, Belgium or Portugal [7]. Tea is consumed by 91% of adults in Ireland [8], with the average person consuming four cups of tea every day [8]. The European Food Safety Authority (EFSA) have established that the upper tolerable intake for fluoride to prevent chronic disease for a healthy adult is 7 mg/day [9]. Furthermore, the EFSA estimated that drinking just 2 cups of tea per day, combined with an average consumption of fluoridated drinking water and use of fluoridated tap water in the preparation of food, but excluding all other sources (including solid foods, toothpaste and dental products), would provide a daily dietary intake of 6 mg per day [4]. So what does this say about fluoride intake among the Irish population? It clearly suggests that chronic fluoride intoxication is a major public health problem in Ireland and that the authorities are turning a blind eye in order to protect a public policy of mandatory fluoridation.

One must assume that the HRB and Food Safety Authority would also be aware that the Regulatory Authorities in China recently banned the importation of tea from Kenya, due to toxic levels of fluoride that were found in tea produced in Kenya [10]. Obviously, the HRB and Food Safety Authority are aware that 90% of tea leaves consumed in the Irish market are sourced from Kenya. If they are not aware of this, or indeed the fluoride content in tea products consumed in Ireland, than this further demonstrates that they are not protecting public health.

So what does this say about the HRB review? Clearly, it is plainly obvious that the HRB review found no definite evidence that water fluoridation was causing harm, because, as with every other review on fluoridation undertaken in this country, they failed abjectly in their duty to protect Irish consumers, by actually measuring the fluoride exposure of the population. On the basis of a large body of published studies and risk assessments of fluoride intake from tea and certain medications, there is absolutely no doubt that the Irish population are chronically exposed to fluoride and that water fluoridation is further contributing to this overexposure. The MRB, Department of Health and Food Safety Authority of Ireland have a legal responsibility to determine the actual exposure to fluoride among the Irish population from food, beverages and medications. Only when they have undertaken this can they determine if the risk of water fluoridation is acceptable. In the absence of such robust studies and the abject failure of regulatory health authorities in Ireland to understand that it is total fluoride intake and exposure that is important when assessing the risk of water fluoridation, any claim that water fluoridation is safe is unscientific and unreliable. To allow this farce to continue may indeed breech medical and public law.

[1] Malin AJ and Till C. Exposure to fluoridated water and attention deficit hyperactivity disorder prevalence among children and adolescents in the United States: an ecological association. Environmental Health 2015, 14:17 doi:10.1186/s12940-015-0003-1
[2] Peckham S, Lowery D, Spencer S. Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water. J Epidemiol Community Health. 2015;Jul;69(7):619-624. doi: 10.1136/jech-2014-204971.
[3] Barry M. Economies in Drug Usage in the Irish Healthcare Setting, National Centre for Pharmacoeconomics, St. James’s Hospital, RoI.  [Accessed 12 June 2015]
[4] Scientific Opinion on Dietary Reference Values for fluoride, EFSA Panel on Dietetic Products, Nutrition, and Allergies: EFSA Journal. 2013;11(8):3332.
[5] National Research Council, Review of Fluoride in Drinking Water, U.S. National Research Council 2006.
[6] Lung SC, Cheng W, Fu CB. Potential exposure and risk of fluoride intakes from tea drinks produced in Taiwan. J Exposure Sci and Environ Epidem. 2008;18:158–166.
[7] Beresniak A, Duru G, Berger G, Dominique Bremond-Gignac. Relationships between black tea consumption and key health indicators in the world: an ecological study. BMJ Open.
[8] North/South Ireland Food Consumption Survey, Irish Universities Nutrition Alliance; 2001.
[9] Kavanagh D, Renehan J. Fluoride in Tea – Its Dental Significance. J Ir Dent Assoc. 1998;44(4):100-105.
[10] China rejects tea from Kenya over high fluoride levels. Business Daily, Kenya. 16th April 2015 Web: [Accessed 12 June 2015].