Supplementary paper on water fluoridation for
Bedford Borough Council Adult Services and
Health Overview and Scrutiny Committee
Written information to supplement answers given to questions
raised by OSC members at their meeting on 16th December 2014
John Morris DDS, MCDH, BDS, FDSRCPS, FDSRCSEd, DDPH Regional Consultant in Dental Public Health
Sandra White BDS, MPH, FDSRCS, FDS(DPH)RCS Director of Dental Public Health
Public Health England
Supplementary paper on water fluoridation
The vast majority (23 out of 26) of the studies reviewed by York to
assess whether fluoridation reduces tooth decay looked at children
for members of Bedford Council Adult
before and after fluoridation schemes were implemented. The
Services and Health OSC
studies, which compared places that had introduced fluoridation with
places that had not, recorded the average levels of tooth decay per
child and/or the percentages of children with and without decay.
The paper submitted by Public Health England to the Bedford Council
Adult Services and Health OSC at its 16th December 2014 meeting
provided information on:
Average benefits identified from analysis of all the results
* the responsibilities of local authorities for promoting the oral health of
When the York team combined and analysed the results of all these
studies, they found that children between the ages of 5 and 15 in
* specific legislation and regulations pertaining to decisions on the
fluoridated areas had, on average, 2.25 fewer decayed, missing and
introduction and maintenance of water fluoridation schemes;
filled teeth than those in non-fluoridated areas (representing
approximately a 40% reduction in decay levels). The York team also
* the evidence on the benefits of fluoridation for oral health;
found that, on average, around 15% more children were completely
free of tooth decay in fluoridated areas than in non-fluoridated ones.
* the evidence on water fluoridation and dental fluorosis; and
Sections 2 and 3 of this paper explain the nature of the studies
* the evidence on safety of water fluoridation in relation to general
reviewed by the York team in relation to the benefits of water
fluoridation over and above other sources of fluoride and its impact on
reducing oral health inequalities between social groups.
OSC members took the opportunity to ask the two PHE
representatives a number of questions, to which they gave verbal
answers. This supplementary paper provides more detail in support of
2. DENTAL BENEFITS OVER AND ABOVE THOSE OF
those answers which, it is hoped, OSC members will find helpful.
OTHER SOURCES OF FLUORIDE
1. “BEFORE AND AFTER” STUDIES OF DENTAL
The York review looked at a range of studies to determine whether
fluoridation achieved dental benefits over and above the effect of other
sources of fluoride such as mouth rinses, tablets and, in particular,
An OSC member asked whether the dental benefits studies reviewed
in the York report were ‘before and after’ studies. In other words, did
those studies compare the state of children’s oral health before a
Again, the majority of these studies (8 out of 10) were conducted
before and after the introduction of a fluoridation scheme in one of the
fluoridation scheme started and after it had been in operation for some
communities being compared. According to the York review, the
evidence suggests that fluoridated water has an effect over and above
that of fluoridated toothpaste and other sources of fluoride.
3. DENTAL BENEFITS IN TERMS OF REDUCED ORAL
non-fluoridated Manchester was greater than between children from
HEALTH INEQUALITIES BETWEEN SOCIAL GROUPS
the most and least affluent social groups in fluoridated Newcastle
upon Tyne. In other words, there was evidence that water fluoridation
reduces oral health inequalities.
Most of these inequalities studies were ‘cross sectional’ rather
than ‘before and after’
The York review also looked at studies that had explored whether or
not fluoridation reduces oral health inequalities between social groups.
4. DENTAL FLUOROSIS
All but three of the 15 studies reviewed were ‘cross sectional’ rather
than ‘before and after’ studies.
An OSC member asked about the prevalence of severe dental
fluorosis (characterised by the pitting of tooth surfaces and brown
In other words, the majority of these studies began after a fluoridation
staining). As stated in the earlier PHE briefing (see sections 6.6 and
scheme had started in a particular community. Then, at a single
6.9) and in the answer given at the December OSC meeting, this level
moment in time, the studies compared the oral health of children from
of dental fluorosis is very rare in the UK.
different social groups in the fluoridated community as well as in
another community that had not been fluoridated.
Severe fluorosis virtually non-existent
Evidence of a narrowing of the gap between the most and least
For example, a 2012 study of 11 to 13 year olds (McGrady et al) found
that only 0.1% of those in fluoridated Newcastle upon Tyne, and 0.2%
in those in non-fluoridated Manchester had severe dental fluorosis.
The cross sectional oral health inequalities studies were not rated by
the York team as being of as high a quality as the ‘before and after’
When the numbers of children with moderate dental fluorosis in the
studies, which indicates that a degree of caution should be applied
study are also taken into account, the prevalence figures were 1.1%
when evaluating the results.
for Newcastle and 0.2% for Manchester. There was, however, an
increased risk of developing mild fluorosis.
However, the York review did find evidence to suggest that the
differences between 5 and 12-year old children from the most and
least affluent social groups in non-fluoridated areas were narrower in
Very low prevalence of fluorosis of possible aesthetic concern
Reduced inequalities identified in recent Newcastle v Manchester
A Medical Research Council report published in 2002 estimated that
between 3 and 4% of people in fluoridated areas of Europe have
dental fluorosis of potential aesthetic concern.
A study (McGrady et al) published 12 years after the York review
looked at the teeth of 11 to 13 year olds in two major English cities.
It found that the difference in the average number of decayed teeth
between children from the most and least affluent social groups in
Some studies have suggested most of the milder forms of dental
5. RECONSTITUTING INFANT FORMULA WITH
fluorosis (characterised by pearlescent areas on tooth surfaces that in
many instances make the teeth look whiter than normal) do not bother
those whose teeth are affected, may not be noticeable and may even
An OSC member asked about claims that the American Dental
be judged more aesthetically pleasing (e.g., Hawley GM, Ellwood RP,
Association (ADA) warns against making up infant formula feeds with
Davies RM (1996): Dental caries, fluorosis and the cosmetic
fluoridated water. The ADA does not do this and has publicly
implications of different TF scores in 14-year old adolescents.
expressed concern that its position on this issue is being
Community Dental Health, 13: 189-192).
Study of 12-year olds found very few had noticed or were
concerned about white marks on teeth
American Dental Association supports fluoridation and advises
parents to continue using fluoridated water to reconstitute infant
In September 2011, the NHS Dental Epidemiology Programme
published its report of a national survey conducted in 2008/09 among
89,000 twelve-year old children who were asked whether they had
The ADA has for long been and remains a strong supporter of the
noticed any white marks on their teeth and whether they were
water fluoridation. In 2011, following a systematic review by an expert
bothered by those marks. The children lived in both non-fluoridated
panel of the evidence on infant formula and dental fluorosis, the ADA’s
and fluoridated parts of the country.
Council on Scientific Affairs published recommendations for parents
and health professionals. Parents were advised to continue to use
http://www.nwph.net/dentalhealth/reports/12 Yr Old_Supplementary
optimally fluoridated water to reconstitute infant formula feed.
The results showed very little difference between regions. Nationally,
16% of 12-year olds said they had noticed white marks on their teeth,
while 84% said they had no white marks or did not know whether they
had any. Across the different regions, the numbers who said they had
The recommendations suggest that, if some parents are especially
marks ranged from 14.6% to 18.4%. In the West Midlands, the most
keen to minimise the risk of dental fluorosis, they should consider
extensively fluoridated region, the figure was 16.8%. In London,
purchasing a ready-to-use feed with a low fluoride content or use
where there is no fluoridation, it was 17.4%.
fluoride-free or low fluoride water to make up the feed. As OSC
members can see, all this is a very long way from warning against the
The white marks were not necessarily all due to dental fluorosis.
use of fluoridated water with infant formula feed.
There are many different causes of ‘enamel opacities’ on tooth
As in the UK, health agencies in the United States recommend
breastfeeding of infants. The American Academy of Paediatrics
Of the small minority of 12-year olds across England who thought their
guidelines for infant nutrition, for example, advocate exclusive
teeth had white marks, about a quarter said they were bothered by
breastfeeding until the child is six months of age.
them. This represented just 4% of all the children who took part in the
the analysis, along with potential confounding variables such as socio-
economic status, birth weight, breastfeeding and educational
An OSC member asked about a report by Grandjean and Landrigan
(published in the Lancet in 2014), which lists fluoride and a number of
other substances as ones they believe to be ‘neurotoxicants’.
The New Zealand research team found no significant differences in IQ
between people in fluoridated and non-fluoridated areas.
They present no supporting arguments for their belief about fluoride,
other than citing a review (which one of them had co-authored) of
International and UK expert bodies
studies on the possible effects of high levels of naturally occurring
fluoride in water in some rural areas of China. Furthermore, since the
There is no suggestion from expert bodies worldwide that
Lancet report was published, Landrigan has gone on public record as
neurotoxicity is likely to occur following exposure to fluoride
saying that in small amounts ‘fluoride is beneficial’.
concentrations present in the UK Public water supply (e.g. University
of York 2000, Medical Research Council in 2002, World Health
Analysis of the studies covered by the review which Grandjean and
Organisation 2004, International Programme on Chemical Safety
Landrigan cite in their 2014 report shows that where the naturally
(IPCS 2002), European Food Safety Authority (EFSA 2005) and the
occurring fluoride in water supplied to these rural communities in
European Commission’s Scientific Committee on Health and
China was at or around the same low level as in artificially fluoridated
Environmental Risks (SCHER) 2011.
communities in England and the United States, children appeared to
have higher average IQs than those living in areas with much higher
While any substance can cause toxic effects if consumed at high
naturally occurring fluoride levels.
enough concentrations or in high enough amounts, the overall
available evidence does not support the conclusion that fluoride at the
New Zealand research paper found no differences in IQ between
levels permitted in UK drinking water causes a neurotoxic effect.
people born and growing up in areas with fluoridated and non-
7. THE SAFETY OF THE SYSTEMS USED TO
A research paper on water fluoridation and IQ in New Zealand has
recently been published which, unlike earlier studies reported mainly
An OSC member asked about the system used to fluoridate water
from China, relates specifically to a comparison of the IQs of people
and, specifically, whether the target was to achieve a level of one part
living in areas with and without community water fluoridation schemes
of fluoride per million parts of water regardless of how much naturally
(Broadbent et al, 2014, Community water fluoridation and intelligence
occurring fluoride is already in the water supply.
– a prospective study in New Zealand.
American Journal of Public
Health, published online May 15, 2014.).
Naturally occurring fluoride is already present in all water supplies.
The precise level may vary from one community to another. It could,
The study tracked individuals who were born in 1972/73 over a period
for example, be 0.1 ppm, 0.2 ppm, 0.3 ppm or higher or lower than
of nearly 40 years, with IQ assessments conducted at regular intervals
that. In Bedford, which is not currently being fluoridated, the natural
between the ages of seven and 38. Use of fluoride toothpaste, and
fluoride level is reported to be on around 0.25 ppm on average.
consumption of fluoride tablets in early life, were taken into account in
Aim to achieve and maintain a fluoride level of one part per
* continuous electronic monitoring of the fluoride concentration, linked
to automatic alarms and shutdown of the process if more than the
permitted level is present;
Whatever the natural background level of fluoride in the water, the
fluoridation equipment at a water treatment plant is calibrated to raise
* a programme of staff training and supervision;
it to, and maintain it at, 1 ppm (the target level set in legislation). In
other words, the amount of fluoride added takes into account the
* sampling of water from taps within the fluoridated area and
natural background level already in the water.
laboratory analysis of the fluoride content in those samples (the
results of which are accessible to the public through water suppliers’
Fluoride compounds permitted under UK legislation
online water quality reports for individual postcodes).
The two fluoride compounds permitted in UK fluoridation schemes
Compliance with the Code of Practice is monitored by the Drinking
must conform with European standards governing chemicals used for
Water Inspectorate. This is achieved through the DWI’s ongoing
water treatment purposes. The manner of their use must also comply
programme of technical audits of water company performance. These
with a Code of Practice (CoP) developed and overseen by the
results are also reported to and monitored by the Drinking Water
Drinking Water Inspectorate (DWI).
Drinking Water Inspectorate Code of Practice on operation of
plant and equipment
The DWI Code of Practice sets out principles for the safe design and
operation of fluoridation installations and are intended to assist water
suppliers in maintaining, as far as practicable, the fluoride
concentration specified in legal agreements with Public Health
England (1 ppm) and ensuring that it does not exceed the maximum
permitted value of 1.5 ppm set out in the Water Supply (Water Quality)
Regulations 2000 (as amended).
Specifically, there are requirements for:
* safe delivery and storage of fluoride chemicals;
* controlling the transfer of fluoride chemicals from bulk storage to the
mains water by means of a ‘day tank’ that holds, as its name
suggests, a maximum of one day’s supply at any time;
* specially calibrated pumps that can add fluoride to the mains supply
only in proportion to the flow of water;