No, in fact, he claims lead is responsible for tooth decay and the improvement in oral health is a result of removing airborne lead contamination. And the “proof” is even in the title of his report – “Global Decline in Tooth Decay correlates with reduced Airborne Lead (Pb) but water Fluoridation prevents further progress“
Mind you, the word “correlate” appears only twice in the document – once in the title and once in the abstract. Nowhere else. Scientists usually restrict the use of words like this to results of proper statistical analyses – but he presents no evidence of a correlation anywhere in the document.
OK, we shouldn’t expect any better. This document is just another one of a series of documents, dressed up as scientific publications, supported by cobbled together citations which are often are irrelevant or don’t support the claims made. Produced by Geoff Pain, well-known Australian anti-fluoride activist, whose concept of scientific publication is to upload his unreviewed documents on to Researchgate. I have written about his citation trawling and false “publication” before in my article An anti-fluoride trick: Impressing the naive with citations
But, perhaps he is on to something. Irrespective of fluoride (he has a hangup about that element) perhaps lead is somehow implicated in oral health problems. So let’s see what the document actually claims.
It has three aims:
1: Rejection of all evidence of the beneficial effects of fluoridation
He describes the evidence for fluoridation as “false” and “absurd.”
Of course, he doesn’t consider for a minute any of the many studies providing evidence of beneficial effects – he just relies on the naive use of selected World Health Organisation (WHO) data which the Fluoride Action Network is well-known for. I have written about this before (see, for example, Fluoridation: Connett’s naive use of WHO data debunked).
This simply argues that the fact that oral health has improved over time in both fluoridated and unfluoridated countries is “proof” that fluoridation has no effect.
Here is the graph he uses:
This figure is meaningless because of the huge influence of inter-country differences on these data, irrespective of fluoridation. That doesn’t require a scientific training to see. These differences introduce so much noise into the data that no conclusion is possible about the influence of fluoridation. Robyn Whyman pointed this out in his report for the National Fluoridation Information Service – “Does delayed tooth eruption negate the effect of water fluoridation?“:
“Studies that appropriately compare the effectiveness of water fluoridation do not compare poorly controlled inter-country population samples. They generally compare age, sex, and where possible ethnicity matched groups from similar areas. Inter-country comparisons of health status, including oral health status, are notoriously difficult to interpret for cause and effect, because there are so many environmental, social and contextual differences that need to be considered.”
The figure does not differentiate between fluoridated and unfluoridated areas within countries – a comparison that is more valid. When we look at the same WHO data for fluoridated and unfluoridated areas we can see the beneficial effect. For example, in the data from the Republic of Ireland:
2: Evidence for an effect of lead exposure on oral health
I can accept that – but certainly would not go as far as Pain’s claim that “lead exposure reduction as the major factor in tooth decay decline.” In fact, the articles he cites suggest that the association of lead exposure with tooth decay is probably weak in most cases.
For example, he cites Gemmel et al., (2002) but ignores what that paper actually says:
“In summary, our findings are consistent with those of several other recent studies (e.g., Campbell et al. 2000; Moss et al. 1999) in suggesting a weak association between children’s lead exposure and caries in primary teeth. The association was region specific, however, suggesting that its magnitude depends on the local distributions of other, more important caries risk factors such as fluoride exposure, diet, and other aspects of environment. The most likely direct role for lead exposure in the development of dental caries, therefore, is as a modifier of host susceptibility. We cannot reject the hypothesis, however, that an elevated lead level is a surrogate or proxy index of some other factor that is itself directly cariogenic.”
Similarly, he cites Martin et al., (2007) but ignores what that paper actually concluded:
“We conclude that this study provides only weak evidence, if any, for an association of low-level lead exposure with dental caries.”
Mind you, he also cites Wiener et al., (2015) who reported:
“This study indicated a strong association of blood lead levels with increasing numbers of carious teeth in children aged 24–72 months.”
But still not evidence that lead is the major factor involved.
Pain ignores suggestions that results may suggest modification of the role of fluoride
I wonder if those who indulge in citation trawling ever actually read the papers they cite. Far from Pain’s citations being evidence of a lack of effect from fluoridation, in almost all cases they suggest the observed effects could be due to modification of the more important effect of fluoride on oral health.
For example, Martin et al., (2007) point out:
” Mechanisms which have been offered to explain the potential association include lead effects on salivary gland development and function (Watson et al., 1997; Bowen, 2001), effects on enamel formation (Lawson et al., 1971; Kato et al., 1977; Appleton, 1991; Watson et al., 1997), and an interference with fluoride uptake in saliva (Gerlach et al., 2002). “
Come on Geoff. Spend some time and actually read the articles you have trawled for your citations.
3: Fluoridation means increase lead concentration in tap water
Having rejected any beneficial role for fluoride and presented lead as the major influence on oral health Pain now puts it all together to “prove” that fluoridation actually enhances tooth decay by increasing dietary lead intake. Why? Because of:
“deliberate addition of Lead as a major contaminant of phosphate fertilizer industrial waste used in Fluoridation plus the exacerbation of Plumbosolvency by Fluoride”
The first point about lead contamination of fluoridating chemicals relies in a naive interpretation of the certificates of analysis required for these chemicals. Just because a very low concentration of lead is recorded in these certificates does not mean this causes an increase in dietary lead intake.
I showed in the article “Chemophobic scaremongering: Much ado about absolutely nothing“ that the fluoridating chemicals contribute less than 0.05% to the lead in tap water – already present from natural sources!
Pain’s reference to “exacerbation of Plumbosolvency” relies on a limited study which reported an association between blood lead levels in children and the treatment of tap water in the US. Of course, the release of lead from pipe fittings can be a problem irrespective of water treatment – which is why authorities recommend one should let the water run for a while first thing in the morning to get rid of such impurities. However, the studies Pain relies on seem to attribute plumbosolvency to specific chlorinating chemicals rather than fluoride.
One can make a simple check, however. In New Zealand authorities regularly make chemical analyses of their tap water available. These do not show increased lead concentrations after fluoridation.
So, again, Geoff Pain has indulged in citation trawling and confirmation bias to produce this report. The citations he uses do not support his claims.
Dietary intake of lead may be one of many factors influencing dental health – but his citations do not in any way support his assertion that it is the “major factor”. Nor do they support his claim that fluoridation does not have a beneficial effect on oral health.
In fact, it is Geoff Pain, not health authorities, who is making the “false” and “absurd” claims.