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Readers following the fluoridation issue have probably come across claims fluoridated water can poison horses. This is just another case of scaremongering by anti-fluoride propagandists – but what is it based on?
The claims go back to Cathy Justus, a horse owner from Pagosa Springs, Colorado. She lost eight horses and four dogs and blames it on their consumption of fluoridated water – which she describes as a “virulent cumulative toxin.” She also claims to “have the sad distinction of owning the first horses to ever be diagnosed with “chronic fluoride poisoning” from artificially fluoridated municipal water.”
Of course, her claim to owning the first horses diagnosed with poisoning by fluoridated water sets off alarm bells straight away. What happened to all the other horses which have consumed fluoridated water? And how could her diagnosis be so different?
What to the experts say?
According to Associate Professor Cynthia Gaskill, toxicology section chief at the Veterinary Diagnostic Laboratory at the University of Kentucky (see Expert discusses fluoridated water and horses in Horsetalk.co.nz):
“A casual internet search of this topic can uncover alarming reports purporting fluoride poisoning in horses from fluoridated municipal water.
“These reports typically are published in non-peer reviewed sources and are missing important information necessary to confirm the diagnosis, to rule out exposure to other fluoride sources, and to eliminate other potential causes.
“A careful review of the peer-reviewed literature in reputable scientific journals showed no published reports documenting fluoride poisoning in horses due to ingestion of fluoridated public water.”
An expert with the Sonoma County Horse Council, Ted S Stashak, concluded in his article The Effects of Artificial Fluoridation of Water (AFW) on Horses:
“Evidence to date indicates that F concentrations allowable in US public water systems are well tolerated by horses and do not cause fluorosis. Supporting this, is a fact that many horses nationwide drink AFW as their major source of water and fluorosis is a very rarely reported condition.”
Why is Cathy Justus so convinced?
It doesn’t take much background reading to see Cathy Justus may be suffering a bit of confirmation bias. In a long letter to the Baltimore Post Express in 2012 she describes her own beliefs and the symptoms of her animals (see Poisoned Horses: Fluoride debate continues). Have a read of at least some of it and you will get the idea.
Cathy is a dyed in the wool anti-fluoride propagandist. Her letter is full of all the “arguments” and relies on the usual anti-fluoride bibles like The case Against Fluoride, The Fluoride Deception, etc. The letter’s tone is typical of someone with these extreme views. So it comes as no surprise to find she is also Fluoride Action Network’s (FAN) National Spokesperson against Fluoride Poisoning in Animals.
She is convinced that her animals’ problems were caused by fluoridated water (as are all the health problems humans currently have) and, in her own mind, that this is not observed by other horse owners just indicates their ignorance and brainwashing.
But wait, there’s more
Cath Justus searched around until she found a veterinary expert who agreed with her bias – in this case, Dr. Lennart Krook, Professor Emeritus, Cornell University. So this whole incident got into the “peer-reviewed” (?), “scientific” (?) literature. To be exact, 2 papers and an editorial in the journal Fluoride – which she describes as the “fluoride bible.” You can check them yourself:
- Krook, L. P., & Justus, C. (2006). Fluoride poisoning of horses from artificially fluoridated drinking water. Fluoride, 39(March), 3–10.
- Justus, C., & Krook, L. P. (2006). Allergy in horses from artificially fluoridated water. Fluoride, 39(June), 89–94.
- Sauerheber, R. (2013). Racehorse breakdowns and artificially fluoridated water in Los Angeles. Fluoride, 46(December), 182–191.
As you might expect from that journal these papers are of poor quality – and, in particular, they present no evidence for the firm beliefs that fluoridated water was the cause of the problems described. Or their equally strong assertions that there is no possibility that feed contamination or other usual causes were absent. As Stashak says, these papers:
“are missing important information necessary to confirm that AFW alone was the cause for the signs of chronic fluorosis in these horses.”
A strongly held, motivated, anecdotal opinion is not evidence and would not be accepted as such by any self-respecting scientific journal. For the life of me, I cannot see how anyone could claim such papers are “peer-reviewed.”
All three authors are organisationally connected with the anti-fluoridation movement. Jutsus through here FAN position. Krook through his membership of the anti-fluoride group Second Look‘s Advisory Board and his membership of the Editorial Board of Fluoride since 1990 and Associate Editor since 2003 (as described in his 2010 obituary of Fluoride). Saueheber is part of James Deal’s (Attorney Deal) anti-fluoride Fluoride Class Action group.
This is just another example of the way anti-fluoride propagandists attempt to convert their biases into “facts.” They have produced multiple articles in the friendly “natural”/alternative health media, and even a video, to support this particular claim. Their tame “scientific” journal, Fluoride, has been dragged in to give academic credibility – and it is unlikely any reputable journal could have been used for this, given the lack of evidence.
In a rather pathetic footnote, Richard D Sauerheber, author of the editorial referred to, gives his institutional affiliation as University of California, San Diego, La Jolla, CA 92037, USA. He also did this in his one other published paper referred to in my post Calcium fluoride and the “soft” water anti-fluoridation myth. In our discussion there he admitted he does not work at that institution, although he did study there many years ago. This is the first time I have come across an author using their university of study as an institutional affiliation in this way. It is deceptive and aimed purely at attempting to claim credibility to himself and any article where he does this. I would be interested to know what officials at that university think of this practice.
Click on image to enlarge
Another interesting article in the Conversation – Trolling our confirmation bias: one bite and we’re easily sucked in by Will Grant. It underlines a point I have often made – that the sensible reader must approach the scientific literature intelligently and critically.
Grant describes a “scientific” prank which fooled many news outlets who reported the “scientific finding”, and, therefore, many readers.
“Last week science journalist John Bohannon revealed that the whole study was an elaborate prank, a piece of terrible science he and documentary film makers Peter Onneken and Diana Löbl – with general practitioner Gunter Frank and financial analyst Alex Droste-Haars – had set up to reveal the corruption at the heart of the “diet research-media complex”.”
The first trick
This was more than just planting a fictitious “science” story:
“To begin the study they recruited a tiny sample of 15 people willing to go on a diet for three weeks. They divided the sample into three groups: one followed a low carbohydrate diet; another followed that diet but also got a 42 gram bar of chocolate every day; and finally the control group were asked to make no changes to their regular diet.
Throughout the experiment the researchers measured the participants in 18 different ways, including their weight, cholesterol, sodium, blood protein levels, their sleep quality and their general well being.”
So – that was the first trick. “Measuring such a tiny sample in so many ways means you’re almost bound to find something vaguely reportable.” As Bohannon explained:
“Think of the measurements as lottery tickets. Each one has a small chance of paying off in the form of a “significant” result that we can spin a story around and sell to the media. The more tickets you buy, the more likely you are to win. We didn’t know exactly what would pan out — the headline could have been that chocolate improves sleep or lowers blood pressure — but we knew our chances of getting at least one “statistically significant” result were pretty good.”
Now to get credibility they needed to publish in a scientific journal:
“But again, Bohannon chose the path that led away from truth, picking a journal from his extensive list of open access academic journals (more on this below). Although the journal, (International Archives of Medicine), looks somewhat like a real academic journal, there was no peer review. It was accepted within 24 hours, and published two weeks later.”
Now for the publicity
Bohannon then whipped up a press release to bait the media :
“The key, Bohannon stated, was to “exploit journalists’ incredible laziness” – to write the press release so that reporters had the story laid out on a plate for them, as it were. As he later wrote, he “felt a queazy mixture of pride and disgust as our lure zinged out into the world”. And a great many swallowed it whole.
Headlines around the world screamed Has the world gone coco? Eating chocolate can help you LOSE weight, Need a ‘sweeter’ way to lose weight? Eat chocolates! and, perhaps more boringly, Study: Chocolate helps weight loss.”
We should be concerned at the way the news media and reporters handle such matters:
“None did the due diligence — such as looking at the journal, looking for details about the number of study participants, or even looking for the institute Bohannon claimed to work for (which exists only as a website) — that was necessary to find out if the study was legitimate.”
This criticism, unfortunately, applies to almost anything in our news media. it really is a matter of “reader beware.”
Grant summarises the process that leads to such devious “science’ stories in the media:
- we’ve got researchers around the world who have taken to heart the dictum that the quantity of research outputs is more important than the quality
- we’ve got journal publishers at the high quality end that care about media impact more than facts
- we’ve got journal publishers at the no-quality end who exploit the desperation of researchers by offering the semblance of publication for a modest sum
- we’ve got media outlets pushing their journalists ever harder to fill our eyeballs with clickbaity and sharebaity content, regardless of truth
- and we’ve got us: simple creatures prone to click, read and share the things that appeal to our already existing biases and baser selves.
Problem wider than the diet industry
Bohannon gives his prank as an example of a “diet research-media complex . . that’s almost rotten to the core.” I agree readers should be far more sceptical of such diet-related science stories. But the problem is far wider than that industry. I think is particularly relevant to any area where people are ideologically motivated, or their feelings of inadequacy or danger, can be manipulated.
Take, for example, the anti-fluoride movement. I have given many examples on this blog of science being misrepresented, or poor quality science being published and promoted by this movement. There are examples of anti-fluoride scientists doing poor quality research – often relying on “statistical fairy tales. Examples of using shonky journals to get poor quality work published. But also examples of such work making its way through inadequate journal peer-review processes.
These anti-fluoride researchers, and their allied activist groups, commonly use press releases to promote their shonky findings. Social media like Facebook and Twitter are roped in to spread the message even more widely.
There is also a link with big business interests – in this case an active anti-fluoride “natural” health business-research-media complex.
So readers beware – there are people, businesses and ideological interests out there attempting to fool you. And they are not averse to using shonky or false science, biased press releases and lazy journalists to do this.
See also: A rough guide to spotting bad science from Compound Interest (Click to enlarge).
Concepts of “natural” and “unnatural” or “artificial” ( or even “industrial”) fluoride often come up in the fluoride debates. Some fluoridation opponents claim “natural” calcium fluoride is quite safe, maybe even necessary for the body, but “artificial fluorides” are toxic. For example, a recent commenter stated:
“I understand that the addition of calcium fluoride to our water supply could be a safe alternative as its use in the small quantities needed would not be harmful. It is not very reactive, but has the desired effect on teeth.”
One of the arguments used is that the presence of calcium is what makes calcium fluoride (CaF2) good, whereas its supposed absence with “artificial” or “industrial” fluorides makes these bad. Anti-fluoride campaigner Eron Brokovich put it this way in here recent “open letter” to the US Institute of Medicine / National Academy of Sciences:
“The 2013 study of chemist Dr. Richard Sauerheber examined the differences between aturally occurring Calcium Fluoride and the highly toxic Industrial Fluoride used in water supplies. Dr. Sauerheber confirmed that the calcium in CaF(sic) makes the fluoride much less absorbable by the human body and therefore less toxic when ingested in that form, whereas the industrial fluoride is . . . highly absorbable . . .”
Sauerheber’s paper (which Brockovich relies on as “evidence”) is a meandering and naive anti-fluoridation rant, published in a shonky journal. But anti-fluoridation propagandists treat “peer-reviewed friendly papers like this as pure gold, so they do tend to rely on them. But don’t take my word for this – here is the citation for anyone wanting to check out the paper
Sauerheber, R. (2013). Physiologic conditions affect toxicity of ingested industrial fluoride. Journal of Environmental and Public Health, 2013,
Sauerheber’s (and therefore Brockovich’s) argument is that calcium in CaF2 reduces assimilation of fluoride into the body and, therefore, renders it non-toxic. He says, for example:
“Natural mineral fluorides are not absorbed well when ingested because of the natural metal cations that accompany fluoride. Having no biologic similarity at all with natural fluoride minerals, industrial manufactured fluoride compounds have cations that replaced those in the natural mineral. . . . . Free fluoride ion in some water supplies as a contaminant is naturally present
from natural fluoride minerals that exhibit low solubility. The equilibrium double-arrow natural partial dissolution of the insoluble solid into some waters is given by:
CaF2(s) ↔ Ca2+(aq) + 2F−(aq).
Industrial fluorides stripped of natural mineral cations lack antidote calcium and are fully assimilated from artificially treated water with insufficient calcium.”
“Fluoride minerals are not neurotoxins, because fluoride is not absorbed from ingested minerals. Free fluoride ion in drinking water can be so classified, but industrial fluoride sources are assimilated more readily than fluoride from hard water or from natural calcium fluoride.”
So, “natural” fluoride, CaF2, is good because the calcium present stops it getting into your blood stream. But “industrial” fluoride is bad because it has no calcium present to inhibit assimilation.
True, the most commonly used fluoridating chemicals are fluorosilicic acid, sodium fluosilicate or sodium fluoride. These do not contain calcium. But wait a minute! These chemicals are drastically diluted in the water supply which already contains calcium from natural sources, and sometimes from water treatment chemicals like lime.
Sauerheber sort of hints at this in his reference to “hard water.” Water “hardness” refers to its mineral content and is usually expressed as the calcium, or calcium carbonate, concentration. It is a common measure of water quality so data is readily available from water treatment plants. In the graph below I compare the calcium concentration from some typical New Zealand water treatment plants with the calcium concentration of a saturated CaF2 solution and the theoretical calcium concentration of “pure” water fluoridated with CaF2 to produce a fluoride concentration of 0.75 ppm (mg/L).
- The majority of NZ waters are considered “soft” with a hardness of 30 ppm (expressed as Ca) or less. I have used this for the NZ maximum.
- The Te Marua, Wainuiomata and Waterloo treatment plants are in the Wellington region. The Hamilton treatment plant is in Hamilton city.
- CaF2 is only slightly soluble so a saturated solution contains approximately 7.5 ppm Ca and 7.5 ppm F, depending on pH and temperature.
All this talk about “natural” CaF2 somehow being “safe” because it contains calcium, whereas the fluoridation chemicals used do not contain calcium, is hogwash There is plenty of calcium even in “soft” drinking water – far more calcium that could be derived from “natural” CaF2 if it were used to produce the optimum concntration fo fluoride used in community water fluoridation.
There are now over 300 blogs on the list, although I am weeding out those which are no longer active or have removed public access to sitemeters. (Let me know if I weed out yours by mistake, or get your stats wrong).
Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters.
Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.
Here are the rankings of New Zealand blogs with publicly available statistics for May 2015. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers.
Meanwhile I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.
You can see data for previous months at Blog Ranks
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Paul Connett, executive director of the Fluoridation Action Network (FAN), told me, during our fluoride debate, that he was writing a scientific paper defining a lower safety limit for fluoride than currently accepted. Nothing has been published yet – although a recent FAN newsletter did refer to a risk assessment paper by him and Bill Hirzy currently under review. I look forward to reading this paper, but I am not holding my breath as neither author has an impressive publication record.
Connett described his risk assessment for fluoride in the debate (see Fluoride debate: Paul Connett’s Closing statement) and he and Hirzy have also made comments on this lately. They are rejecting the current risk assessment, based on the incidence of severe dental fluorosis, and using the incidence of IQ deficits instead. To this end, they are heavily promoting the work of Choi et al., (2012) and Xiang et al., (2003) (which reported IQ deficits in areas where fluorosis is endemic). They are also attempting to rubbish published research (such as Broadbent et al., 2014) which show no significant IQ deficits at fluoride concentrations used in community water fluoridation.
Connett and Hirzy have also organised campaigns to congressional representatives in their effort to force a downward revision of the Environmental Protection Agency’s (EPA) standards for fluoridation.
Connett’s approach is a desk study – these guys are not going to dirty their hands by doing their own research to get useful data. They are taking a value which they claim represent the lowest concentration of fluoride in drinking water below which no IQ deficit was found. They then apply “safety factors” to effectively conclude the only safe concentration is zero (see Scientist says EPA safe water fluoride levels must be zero)!
I will be a bit surprised if they manage to squeeze their paper though a decent review process because their approach is shonky. Look at the way they use the data from Xiang et al., (2003). (I have used the presentations by Connett and Hirzy at last February’s Sydney anti-fluoride conference as sources here). As I pointed out in Connett fiddles the data on fluoride, this data actually does not show a strong relationship between IQ and fluoride. The figure (from Xiang et al., 2003) shows the relationship between IQ and urinary fluoride and, in this case, the fluoride explains only about 3% of the variance in IQ.
Despite being statistically significant (p=0.003) this is certainly not evidence for a causative relationship. Clearly other, unconsidered, factors contribute to the variance and if these were considered the relationship with fluoride may be non-significant.
(Readers may notice the figure uses data for urinary not drinking water fluoride. Unfortunately, Xiang did not give a similar figure for fluoride concentration in drinking water. I have contacted him requesting the similar data for drinking water but so far have not had a meaningful response. Xiang did report drinking water fluoride is well correlated with urine fluoride so the above figure probably gives a good idea of the variability in drinking water fluoride as well).
Connett and Hirzy effectively ignore the high variability in the data and rely on a trick to get this second graph. By splitting the concentration range into groups and taking the mean IQ for each group they make the situation look a lot more respectable. Who would guess from this trick that fluoride only explained about 3% of the IQ variance?
Connett illustrates his next step with this slide.
He then claims that IQ deficits occur at a fluoride concentration of 1.26 ppm – he appears to have simply subtracted the value of one standard deviation from the mean of the lowest concentration group associated with a significantly different mean IQ to that of Xiang’s “control” group – Xinhaui village. That is strange because surely the first figure indicates that low IQ values occur even for children with very low urinary fluoride, and most probably drinking water fluoride.
Connett then uses a safety factor of 10 (“to account for the wide range of sensitivity expected for any toxic substance in a large population”). Of course, this produces a maximum “safe” concentration of 0.13 ppm – which rules out all fluoridated water – and most natural water sources!
Connett goes on to promise his offsider, Bill Hirzy, will elaborate on the method they issued. Hirzy’s presentation did mention fluoride intake from other sources besides water. He then presents his conclusion on what the “safe daily dose” is fluoride – but no explanation of why! All the preceding slides in his presentation where self-justifying descriptions of his qualifications, employment history and how great his organisation, FAN, is.
Connett and Hirzy are claiming IQ deficits are more important than dental fluorosis for setting of maximum fluoridation levels in drinking water. They are campaigning to get this accepted by legislators and the EPA.
Connett has been promising publication in a scientific journal for several years and recently implied that a paper is under review. If their publication efforts are successful a more critical assessment of their approach will be possible.
Available information indicates Connett and Hirzy have no original data but are relying on data from a study of children in an area of endemic fluorosis in China. They are refusing to accept published information from areas where community water fluoridation exists.
Their analysis also appears to rely on a tricky processing of the data to obscure the fact that fluoride probably only explains about 3% of the variance in IQ measured by the Chinese researchers! Legislators and policy makers would be foolish indeed to make changes to fluoridation standards on the basis of such data and poor analysis.
I could, of course, be wrong so eagerly await the Connett & Hirzy (2016?) paper.
The controversial Lancet editor, Richard Horton, has produced an opinion piece which some are interpreting as an attack on medical science, if not science in general. His article, What is medicine’s 5 sigma?, is being touted by websites like Collective Evolution as authoritative “evidence,” or justification, for their attempts to manufacture doubt on scientific issues (see Editor In Chief Of World’s Best Known Medical Journal: Half Of All The Literature Is False). And, of course, these messages are spread far and wide in social media like Facebook and Twitter by activists for various anti-science causes.
Horton, of course, exaggerates. He calls a spade a shovel – or even a giant earth moving machine. That is music to the ears of propagandists and manufacturers of doubt in the anti-vaccination, anti-fluoridation or even climate change denial movements. But, putting aside the damage such exaggeration causes for a moment, I do sympathise with some of Horton’s claims.
Provisional nature fo scientific knowledge
Horton begins with the statement “A lot of what is published is incorrect.”
While he appears to think this claim has shock value it is hardly news to scientific researchers. By its very nature, scientific knowledge is both provisional and incomplete. In the real world, no scientific idea or theory can accord completely with the true objective reality. We are always dealing with just a part of that reality. And our theories are always being replaced by new, updated and more complete theories which give better explanations of reality. Let’s be clear, though, in most cases this is not a simple mechanical replacement but usually a modification to, or improvement of, existing theories.
So, yes, published science is “incorrect” in that it is always incomplete and provisional. It is always open to sceptical consideration and improvement – or even rejection.
However, Horton has really brought in the earth-moving machinery when he advances “the idea that something has gone fundamentally wrong with one of our greatest human creations.”
Modern science is indeed “one of our greatest human creations” – despite the fact that it is by its very nature incomplete and imperfect. Despite all the human problems influencing science it has still enabled us to solve many problems, to provide a more comfortable and safer existence for much of the world’s population and provided us with amazing technology (which critics of science enthusiastically use without being aware of the irony involved).
Sure, we still have many pressing problems to solve but no-one can seriously believe that science cannot contribute to the solution of these problems. In the end, despite all the human frailties inherent in such human endeavours, no other approach to obtaining knowledge and solving problems can seriously compete with science.
Some real problems
Horton gets specific:
“The case against science is straightforward: much of the scientific literature, perhaps half, may simply be untrue. Afflicted by studies with small sample sizes, tiny effects, invalid exploratory analyses, and flagrant conflicts of interest, together with an obsession for pursuing fashionable trends of dubious importance, science has taken a turn towards darkness.”
He also refers to those papers relying on correlations without showing causation, saying:
“Our love of “significance” pollutes the literature with many a statistical fairy-tale.”
But these problems are, in essence, not new and do not justify his purple prose about “a turn towards darkness.” That prose is rather hypocritical considering his own role in the publication of, and resistance to the retraction of, Andrew Wakefield’s article claiming a causal link between standard childhood vaccinations (measles, mumps and rubella) and autism (see Why Is Richard Horton Still The Editor Of The Lancet?).
The fact is that poor quality research does get published – even by reputable journals like The Lancet (see for example Repeating bad science on fluoride). Poor quality research is not always knocked back, or improved, by the peer review processes journals use. These peer review processes themselves can be very flawed and even suffer from cronyism (see Poor peer review – and its consequences) and Poor peer-review – a case study) .
Many studies are poorly designed, report tiny effects and use small sample sizes. Many rely on statistically significant correlations which may be meaningless without any evidence for causation. Peer reviewers and journal editors, if they are actually conscientiously doing their jobs, are forced to make judgment calls. There is an argument for sometimes getting such studies into the literature where they can be critically examined and discussed. (Horton himself justified his decision to publish Andrew Wakefield’s article, which he acknowledged was an inferior study by claiming it would generate debate on the autism/vaccine issue).
But this backfires when uncritical journalists report the studies as scientifically credible, even gospel truth, when they are far from it. This is compounded by propagandists for activist groups who, confirmation bias in full flight, latch on to such studies to give “scientific authenticity” to their unscientific claims. And then promote them far and wide.
Recently we saw this with published papers claiming a link between fluoridation and thyroid problems (Peckham et al., 2015 – see Paper claiming water fluoridation linked to hypothyroidism slammed by experts) and ADHD (Malin and Till, 2015 – see ADHD linked to elevation not fluoridation). These papers were prime examples of Horton’s “statistical fairy tales.”
So, I am repeating a theme I often promote here. When it comes to the scientific literature it really is a matter of “reader beware.”
The reader must approach this literature carefully – intelligently and critically. The reader has the task of identifying “statistical fairy tales,” poor study designs and problems of tiny effects or small sample sizes. If the reader does not have the ability to do so they need to seek the opinions of qualified experts – and I don’t mean the self-appointed “world experts” leading activists groups or the google-informed commenters who seem to dominate social media and the internet.
After all, it is the real expert, many of whom are active researchers, who critically assess the scientific literature on a daily basis. And if they are participants in an active scientific community problems of confirmation bias are reduced.
The “reader beware” approach is even more necessary with the “scientific” claims often bandied about in the popular news media – mainstream media and especially the ideologically motivated “alternative” media.
I am an avid reader of the NZ Listener – which I consider a reputable mainstream journal. But every week I am annoyed by the small snippets reporting some new scientific claim (usually related to popular health issues) relying on individual scientific papers which I would place in Horton’s group of “statistical fairy tales.” I hope most readers are intelligent enough to seek further advice before taking such reports seriously.
But this annoyance is minor compared with what I feel about the rubbish I see daily on the internet daily. Ideologically motivated activists dominate social media here. They opportunistically link to such media reports, and even the original scientific papers, to give “scientific justification,” and confirmation bias for their unscientific messages.
When it comes to the internet one cannot repeat often enough – reader beware.
I keep coming across this very naive form of chemophobic scare-mongering – the use of safety data sheets to frighten consumers about trace chemicals in their environment, food and drink.
Here is an example anti-fluoridation propagandists continually use – safety data sheets for fluoridation chemicals like fluorosilicic acid. Often these people simply reproduce the image without comment – thinking this somehow proves their argument!
I have discussed this issue for water treatment chemicals before (see Water treatment chemicals – why pick on fluoride?).
First, we need to be clear – Safety Data Sheets (or Material Safety Data Sheets) are not relevant to the chemicals we come across in our food drink – at the concentration they exist in these foods or drink. The safety data sheets are there for the use of those workers who must handle, transport and dispose of concentrated chemicals. As Wikipedia explains:
“A SDS [Safety Data Sheet] for a substance is not primarily intended for use by the general consumer, focusing instead on the hazards of working with the material in an occupational setting.”
In the article I link to above I give information, including that from safety data sheets, for the range of chemicals used in water treatment. Chemicals like Aluminium sulphate or alum, used as a flocculation and coagulation agent and chlorine which is used as a disinfection agent (here is the safety data sheet for chlorine).
The safety data sheets for these chemicals can be just as scary as for fluorosilicic acid. Even scarier for chlorine, which was used as a chemical weapon in the first world war. And the information is important for the people handling the concentrated chemicals, manufacturing them, transporting them and disposing of them to waste where necessary.
But these sheets are completely irrelevant to people interested in the safety and nutritional value of their food which do not contain such concentrated chemicals (except for water, of course).