A Dash of Science, Social Media and VARD

Yesterday I recorded a podcast with Matthew Lee Loftus (from The Credible Hulk) and Christopher El Sergio for A Dash of Science, all about science communication and social media. It was a brilliant chat – I won’t go into lots of details of what we covered, but if you’d like to hear it (you know you do!) the direct link is: Communicating Science on Social Media. You can also pick it up on iTunes and/or Tune In.

After our conversation ended I remembered something I developed little while ago, after marking a particularly infuriating research homework where a quarter of the class wrote down that Mendeleev was awarded a Nobel prize for his work on the Periodic Table. For the record: he never received the honour. He was recommended for the prize but famously (at least, I thought it was famously!) the 1906 prize was given to Henri Moissan instead, probably due to a grudge held by Svante Arrhenius of Arrhenius Equation fame (it’s a good story, check it out).

Mendeleev was never awarded a Nobel prize.

Does it really matter if a few students believe that Mendeleev won a Nobel prize? That’s not really harming anyone, is it? Maybe not, but on the other hand, perhaps it’s part of a long and slippery slope greased with ‘alternative facts’ which is leading us to, well, shall we say, situations and decisions that may not be in our best interests as a society.

How to encourage students to do at least a little bit of fact-checking? Of course, you could produce a long list of Things That One Should Do to check information, but I reasoned that while students might read such a list, and even agree with the principles, they were unlikely to get into the habit of applying them and probably quite likely to immediately forget all about it.

Instead I tried to come up with something short, simple and memorable, and here it is (feel free to share this):

Fact-checking isn’t easy; it’s VARD

The four points I focused on spell out VARD, which stands for…

Verify

V is for verify, which means: can you find other sources saying the same thing? Now, chances are, you can always find something that agrees with a particular piece of information, if you look hard enough. There are plenty of sites out there that will tell you that lemons ‘alkalise’ the body, for example (they don’t), that it’s safe to eat apricot kernels (it’s not) and that black salve is an effective treatment for skin cancer (nope).

However, if you’re reasonably open-minded when you start, chances are good that you’ll find both sides of the ‘story’ and that will, at the very least, get you thinking about which version is more trustworthy.

Author

A is for author. I often hear swathes of content being disparaged purely based on its nature. You know the sort of thing: “that’s just a blog,” or “you can’t trust newspaper articles”. I think this is wrong-headed. What matters more is who wrote that piece and what are their qualifications? I’d argue that a blog post about medical issues written by a medical doctor (for example, virtually anything on the marvellous Science Based Medicine) is likely to be a pretty reliable source. Conversely, there’s been more than one thing that’s made it into the scientific literature which has later turned out to be flawed or even flat false (such as Wakefield’s famous 1998 paper). It’s also worth asking what someone’s background is: Stephanie Seneff, for example, is highly qualified in the fields of artificial intelligence and computer science, but does that mean we should trust her controversial opinions in biology and medicine? Probably not.

You may not always be able to tell who the author is, or have time to dig into their motivations, but it’s nevertheless a good question to keep in the back of your mind.

Reasonableness

Be honest: is that story really likely? Or is it just shocking?

R is for reasonableness. Which is a pain to spell or even say, but it’s important so I’m sticking with it. It’s a sense-check. Human beings love a good story, and the best stories have unexpected twists and turns. That’s why medical scare-stories pop up in newspapers with such depressing regularity. No, ketchup isn’t giving you cancer. No, our children really aren’t being poisoned by plastics. But the truth doesn’t always make a good headline. In fact, when it comes to science, the more some ‘exciting finding’ is plastered over news sites, the less you should probably trust it – because the chances are that the exciting version being reported bears almost no resemblance to the researchers’ original conculsions.

Be honest and ask yourself: does this really seem likely? Or would I just like it to be true because it’s a great story?

Date

If a surprising story has just appeared, give it twenty-four hours – chances are if there are major issues with the information someone else will come forward.

D is for date. The obvious situation is when information is so old that it’s been superseded by something else. This is easy: just look for something more recent. However, the other side of this coin is probably more relevant in these days of rolling news and instant sharing of articles: something can blow up at short notice, especially something topical, and it later turns out that not all the facts were known. Take, for example, the famous green swimming pools in the 2016 Olympics, which more than one writer attributed to copper salts in the pool water before the full facts were revealed a few days later. Inevitably, the ‘corrected’ version is far less interesting than the earlier speculation, and so that’s what everyone remembers.

If something controversial and shocking has just appeared, give it twenty-four hours. If there’s something terribly wrong with it, chances are someone will pick up on it in that time.

It’s not easy; it’s VARD

And that’s it: Verify, Author, Reasonableness, Date. It doesn’t cover every eventuality, but if you keep these points in the back of your mind it will definitely help you to separate the ‘probably true’ from the ‘almost certainly bollocks’.

Good luck out there!

Now why not go and listen to that podcast 🙂


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Chemical du jour: how bad is BPA, really?

BPA is an additive in many plastics

When I was writing my summary of 2017 I said that there would, very probably, be some sort of food health scare at the start of 2018. It’s the natural order of things: first we eat and drink the calorie requirement of a small blue whale over Christmas and New Year, and then, lo, we must be made to suffer the guilt in January. By Easter, of course, it’s all forgotten and we can cheerfully stuff ourselves with chocolate eggs.

Last year it was crispy potatoes, and the year before that it was something ridiculous about sugar in ketchup causing cancer (it’s the same sugar that’s in everything, why ketchup? Why?). This year, though, it seems that the nasty chemical of the day is not something that’s in our food so much as around it.

Because this year the villain of the piece appears to be BPA, otherwise known as Bisphenol A or, to give it its IUPAC name, 4,4′-(propane-2,2-diyl)diphenol.

BPA is an additive in plastics. At the end of last year an excellent documentary aired on the BBC called Blue Planet II, all about our planet’s oceans. It featured amazing, jaw-dropping footage of wildlife. It also featured some extremely shocking images of plastic waste, and the harm it causes.

Plastic waste is a serious problem

Plastic waste, particularly plastic waste which is improperly disposed of and consequently ends up in the wrong place, is indisputably something that needs to be addressed. But this highlighting of the plastic waste problem had an unintended consequence: where was the story going to go? Everyone is writing about how plastic is bad, went (I imagine) editorial meetings in offices around the country – find me a story showing that plastic is even WORSE than we thought!

Really, it was inevitable that a ‘not only is plastic bad for the environment, but it’s bad for you, too!’ theme was going to emerge. It started, sort of, with a headline in The Sun newspaper: “Shopping receipts could ‘increase your cancer risk’ – as 93% contain dangerous chemicals also linked to infertility. Shopping receipts are, of course, not made of plastic – but the article’s sub-heading stated that “BPA is used to make plastics”, so the implication was clear enough.

Then the rather confusing: “Plastic chemical linked to male infertility in majority of teenagers, study suggests” appeared in The Telegraph (more on this in a bit), and the whole thing exploded. Search for BPA in Google News now and there is everything from “5 Ways to Reduce Your Exposure to Toxic BPA” to “gender-bending chemicals found in plastic and linked to breast and prostate cancer are found in 86% of teenagers”.

Yikes. It’s all quite scary. It’s true that right now you can’t really avoid plastic. Look around you and it’s likely that you’ll immediately see lots of plastic objects, and that’s before you even try to consider all the everyday things which have plastic coatings that aren’t immediately obvious. If you have young children, you’re probably drowning in plastic toys, cups, plates and bottles. We’re pretty much touching plastic continually throughout our day. How concerned should we be?

As the Hitchiker’s Guide to the Galaxy says, Don’t Panic. Plastic (like planet Earth in the Guide) can probably be summed up as mostly harmless, at least from a BPA point of view if not an environmental one.

BPA is a rather pleasingly symmetrical molecule with two phenol groups. (A big model of this would make a wonderfully ironic pair of sunglasses, wouldn’t it?) It was first synthesized by the Russian chemist Alexander Dianin in the late 19th century. It’s made by reacting acetone – which is where the “A” in the name comes from – with two phenol molecules. It’s actually a very simple reaction, although the product does need to be carefully purified, since large amounts of phenol are used to ensure a good yield.

It’s been used commercially since the fifties, and millions of tonnes of BPA are now produced worldwide each year. BPA is used to make plastics which are clear and tough – two characteristics which are often valued, especially for things like waterproof coatings, bottles and food containers.

The concern is that BPA is an endocrine disruptor, meaning that it interferes with hormone systems. In particular, it’s a known xenoestrogen, in other words it mimics the female hormone estrogen. Animal studies have suggested possible links to certain cancers, infertility, neurological problems and other diseases. A lot of the work is fairly small-scale and, as I’ve mentioned, focused on animal studies (rather than looking directly at effects in humans). Where humans have been studied it’s usually been populations that are exposed to especially high BPA levels (epoxy resin painters, for example). Still, it builds up into quite a damning picture.

BPA has been banned from baby bottles in many countries, including the USA and Europe

Of course, we don’t normally eat plastic, but BPA can leach from the plastic into the food or drink that’s in the plastic, and much more so if the plastic is heated. Because of these concerns, BPA has been banned from baby bottles (which tend to be heated, both for sterilisation and to warm the milk) in several countries, including the whole of Europe, for some years now. “BPA free” labels are a fairly common sight on baby products these days. BPA might also get onto our skin from, for example, those thermal paper receipts The Sun article mentioned, and then into our mouths when we eat. Our bodies break down and excrete the chemical fairly quickly, in as little as 6 hours, but because it’s so common in our environment most of us are continually meeting new sources of it.

How much are we getting, though? This is a critical question, because as I’m forever saying, the dose makes the poison. Arsenic is a deadly poison at high levels, but most of us – were we to undergo some sort of very sensitive test – would probably find we have traces of it in our systems, because it’s a naturally-occuring mineral. It’s nothing to worry about, unless for some reason the levels become too high.

When it comes to BPA, different countries have different guidelines. The European Food Safety Authority recommended in January 2015 that the TDI (tolerable daily intake) should be reduced from 50 to 4 µg/kg body weight/day (there are plans for a new assessment in 2018, so it might change again). For a 75 kg adult, that translates to about 0.0003 g per day. A USA Federal Drug and Administration document from 2014 suggests a NOAEL (no-observed-adverse-effect-level) of 5 mg/kg bw/day, which translates to 0.375 g per day for the same 75 kg adult. NOAEL values are usually much higher than TDIs, so these two figures aren’t as incompatible as they might appear. Tolerable daily intake values tend to have a lot of additional “just in case” tossed into them – being rather more guidance than science.

The European Food Standards Authority published a detailed review of the evidence in 2015 (click for a summary)

So, how much BPA are we exposed to? I’m going to stick to Europe, because that’s where I’m based (for now…), and trying to look at all the different countries is horribly complicated. Besides, EFSA produced a really helpful executive summary of their findings in 2015, which makes it much easier to find the pertinent information.

The key points are these: most of our exposure comes from food. Infants, children and adolescents have the highest dietary exposures to BPA, probably because they eat and drink more per kilogram of body weight. The estimated average was 0.375 µg/kg bw per day.  For adult women the estimated average was 0.132 µg/kg bw per day, and for men it was 0.126 µg/kg bw per day.

When it came to thermal paper and other non-dietary exposure (mostly from dust, toys and cosmetics), the numbers were smaller, but the panel admitted there was a fair bit of uncertainty here. The total exposure from all sources was somewhere in the region of 1 µg/kg bw per day for all the age groups, with adolescents and young children edging more toward values of 1.5 µg/kg bw per day (this will be important in a minute).

Note that all of these numbers are significantly less than the, conservative, tolerable daily intake value of 4 µg/kg bw per day recommended by EFSA.

Here’s the important bit: the panel concluded that there is “no health concern for BPA at the estimated levels of exposure” as far as diet goes. They also said that this applied “to prenatally exposed children” (in other words, one less thing for pregnant women to worry about).

When it came to total exposure, i.e. diet and exposure from other sources such as thermal paper they concluded that “the health concern for BPA is low at the estimated levels of exposure”.

The factsheet that was published alongside the full document summarises the results as follows: “BPA poses no health risk to consumers because current exposure to the chemical is too low to cause harm.”

Like I said: Don’t Panic.

What about those frankly quite terrifying headlines? Well, firstly The Sun article was based on some work conducted on a grand total of 208 receipts collected in Southeast Michigan in the USA from only 39 unique business locations. That’s a pretty small sample and not, I’d suggest, perhaps terribly relevant to the readership of a British newspaper. Worse, the actual levels of BPA weren’t measured in the large majority of samples – they only tested to see if it was there, not how much was there. There was nothing conclusive at all to suggest that the levels in the receipts might be enough to “increase your cancer risk”. All in all, it was pretty meaningless. We already knew there was BPA in thermal receipt paper – no one was hiding that information (it’s literally in the second paragraph of the Wikipedia page on BPA).

The Telegraph article, and the many others it appeared to spawn, also weren’t based on especially rigorous work and, worse, totally misrepresented the findings in any case. Firstly, let’s consider that headline: “Plastic chemical linked to male infertility in majority of teenagers, study suggests”. What does that mean? Are they suggesting that teenagers are displaying infertility? No, of course not. They didn’t want to put “BPA” in the headline because that, apparently, would be too confusing for their readers. So instead they’ve replaced “BPA” with “plastic chemical linked to male infertility”, which is so much more straightforward, isn’t it?

And they don’t mean it’s linked to infertility in the majority of teenagers, they mean it’s linked to infertility and it’s in the majority of teenager’s bodies. I do appreciate that journalists rarely write headlines – this isn’t a criticism of the poor writer who turned in perfectly good copy – but that is confusing and misleading headline-writing of the highest order. Ugh.

Plus, as I commented back there, that wasn’t even the conclusion of the study, which was actually an experiment carried out by students under the supervision of a local university. The key finding was not that, horror, teenagers have BPA in their bodies. The researchers assumed that almost all of the teenagers would have BPA in their bodies – as the EFSA report showed, most people do. No, the conclusion was actually that the teenagers – 94 of them – had been unable to significantly reduce their levels of BPA by changing their diet and lifestyle. Although the paper admits the conditions weren’t well-controlled. Basically, they asked a group of 17-19 year-olds to avoid plastic, and worked on the basis that their account of doing so was accurate.

And how much did the teenagers have in their samples? The average was 1.22 ng/ml, in urine samples (ng = nanogram). Now, even if we assume that these levels apply to all human tissue (which they almost certainly don’t) and that therefore the students had roughly 1.22 ng per gram of body weight, that only translates to, very approximately, 1.22 micrograms (µg) per kilogram of body weight.

Wait a second… what did EFSA say again…. ah yes, they estimated total exposures of 1.449 µg/kg bw per day for adolescents.

Sooooo basically a very similar value, then? And the EFSA, after looking at multiple studies in painstaking detail, concluded that “BPA poses no health risk to consumers”.

Is this grounds for multiple hysterical, fear-mongering headlines? I really don’t think it is.

It is interesting that the teenagers were unable to reduce their BPA levels. Because it’s broken down and excreted quite quickly by the body, you might expect that reducing exposure would have a bigger effect – but really all we can say here is that this needs to be repeated with far more tightly-controlled conditions. Who knows what the students did, and didn’t, actually handle and eat. Perhaps their school environment contains high levels of BPA in dust for some reason (new buildings or equipment, maybe?), and so it was virtually impossible to avoid. Who knows.

In summary, despite the scary headlines there really is no need to worry too much about BPA from plastics or receipts. It may be worth avoiding heating plastic, since we know that increases the amound of BPA that makes its way into food – although it’s important to stress that there’s no evidence that microwaving plastic containers causes levels to be above safe limits. Still, if you wanted to be cautious you could choose to put food into a ceramic or glass bowl, covered with a plate rather than clingfilm. It’ll save you money on your clingfilm bills anyway, and it means less plastic waste, which is no bad thing.

Roll on Easter…


Like the Chronicle Flask’s Facebook page for regular updates, or follow @chronicleflask on Twitter. All content is © Kat Day 2018. You may share or link to anything here, but you must reference this site if you do.


All comments are moderated. Abusive comments will be deleted, as will any comments referring to posts on this site which have had comments disabled.