Look to your left, Mr. Bateson

It has always been very funny to me that anti-vaccine types who believe, desperately, that thimerosal causes autism (because mercury) are quick to blame the MMR vaccine for autism as well. MMR never had thimerosal in it, so it must be that it causes autism some other way. Anti-vaccine activists bend over backwards to find evidence that fits their theory, not the other way around. One such piece of work is Tony Bateson, he’s been looking for autistic children who are unvaccinated:

“WIth Britain’s annual birth rate of 600,000 upwards this meant that 60,000 a year for forty years, 2.4 millions may not have had paediatric vaccines! Astonishing then that I could not find even a handful of unvaccinated people who were autistic out of that vast pool.”

He reiterates this demand for unvaccinated autistic children in comments on science blogs:

“Of coourse it is extremely difficult to find an environmental cause for autism when an enormous barrage of dollars is directed towards frustrating that search. For my small part I have relentlessly searched for autistic people who are not vaccinated without ever finding one who is unequivocally so. I do not mean just amongst my neighboours and acquaintances I mean amongst hundreds of autistic families I know (I was Vice Chairman of the UK National Autistic Society and knew hundreds) and as a prolific writer, broadcaster and website owner, I made contact with thousands. Just where are the unvaccinated?”

And here:

“Autism is decidely not congenital. Autism is not present in unvaccinated peoples nor in the unvaccinated population of the UK.”

Such conviction to his beliefs. He must truly believe it.

And on Left Brain / Right Brain:

“For heavens sake where do they all come from? Look it is simple – there are no autistic people in populations where there has been no vaccination! Over three million kids have not been vaccinated in the UK where vaccination is optional and parents have chosen not to vaccinate. More than ten years of aggressive searching in this group has failed to find autistic people! Like the Amish, like Homefirst there are no autistic people in this group.

Let the vaccine lobby explain what the prevalence of autism is in unvaccinated groups. That is the only evidence worth having. Wake up America.”

The only person who needs to wake up is Mr. Bateson. He writes for Age of Autism, right? Kim Stagliano, who writes and is an editor at AoA has a child who is not vaccinated and is autistic. So, there you go, Mr. Bateson, that’s one. Shall we continue?

One of the reasons why we scientists and reasonable people can say without a doubt that autism is not caused by vaccines is because we’ve compared rates of autism in vaccinated and unvaccinated populations. To do so, we required to find unvaccinated with autism, otherwise we wouldn’t have a rate of autism in that population. (Zero divided by any number throws out an error in any statistical package… And in math, you cannot divide zero.) Mr. Bateson could go to any of those researchers, email them, and just ask for the numbers of unvaccinated autistics. In a perfect world, the fool would just pick up those papers and look at the tables.

But that would be a reality-shattering proposition for him, I suppose. Like any other anti-vaccine activist, he comes off at the kind of person who would crumble into a heap of goo at the sight of evidence conflicting with his reality.

The Weirdo John Stone from Age of Autism agrees that thimerosal is not toxic

You know what I love about John Stone, the resident weirdo at Age of Autism? I love that he thinks he knows science then posts something that he thinks agrees with him when it clearly doesn’t. For example, here is a comment of his in which he thinks that the idea that methylmercury is just as bad as ethylmercury:

“The person who doesn’t do science is Mr Kluger. Here we are from 2013:

J Appl Toxicol. 2013 Aug;33(8):700-11. doi: 10.1002/jat.2855. Epub 2013 Feb 11.
Toxicity of ethylmercury (and Thimerosal): a comparison with methylmercury.
Dórea JG1, Farina M, Rocha JB.
Author information

Ethylmercury (etHg) is derived from the metabolism of thimerosal (o-carboxyphenyl-thio-ethyl-sodium salt), which is the most widely used form of organic mercury. Because of its application as a vaccine preservative, almost every human and animal (domestic and farmed) that has been immunized with thimerosal-containing vaccines has been exposed to etHg. Although methylmercury (meHg) is considered a hazardous substance that is to be avoided even at small levels when consumed in foods such as seafood and rice (in Asia), the World Health Organization considers small doses of thimerosal safe regardless of multiple/repetitive exposures to vaccines that are predominantly taken during pregnancy or infancy. We have reviewed in vitro and in vivo studies that compare the toxicological parameters among etHg and other forms of mercury (predominantly meHg) to assess their relative toxicities and potential to cause cumulative insults. In vitro studies comparing etHg with meHg demonstrate equivalent measured outcomes for cardiovascular, neural and immune cells. However, under in vivo conditions, evidence indicates a distinct toxicokinetic profile between meHg and etHg, favoring a shorter blood half-life, attendant compartment distribution and the elimination of etHg compared with meHg. EtHg’s toxicity profile is different from that of meHg, leading to different exposure and toxicity risks. Therefore, in real-life scenarios, a simultaneous exposure to both etHg and meHg might result in enhanced neurotoxic effects in developing mammals. However, our knowledge on this subject is still incomplete, and studies are required to address the predictability of the additive or synergic toxicological effects of etHg and meHg (or other neurotoxicants).

Copyright © 2013 John Wiley & Sons, Ltd.”

All bolding is mine, by the way.

I’ve told you before that in vitro (in a lab) is different than in vivo (in an actual organism), and this supports it. But, in the weirdo’s crazy little world, this one study is the Holy Grail of comparing ethyl mercury to methyl mercury. Why? I have no clue. This study confirms that biological systems are more complex than cells in a petri dish, and that we react differently to the ethyl mercury that thimerosal metabolizes into. In essence, we don’t get hurt or become autistic, like anti-vaccine activists and weirdos might want us to believe.

So thank you, John Stone of Age of Autism, for confirming this for us.


What does autism look like?

If you asked me what a child with Down syndrome looks like, I would probably tell you that the child has slanted eyes, a small chin, flat and wide face, a short neck, and extra space between the first and second toe. (I got this from Wikipedia, by the way.) These physical characteristics come from the extra chromosome found in people with Down syndrome. The same can be said for people with other disorders and conditions that affect both body and mind. But what does autism look like?

Well, if you ask Lyn Redwood, vice-president of SafeMinds (and anti-vaccine group that pushes the thimerosal-autism pseudoconnection), a child with autism looks like a child with mercury poisoning. Why? Because her child looked just like a child with mercury poisoning, and her child (according to her) is autistic because of vaccines:

“When he was born, my son weighed close to 9 lbs. He was a happy baby who ate and slept well, smiled, cooed, walked, and talked all by one year. But shortly after his first birthday, my son began to regress physically and developmentally, losing speech, eye contact, and social interactions. He no longer slept through the night and suddenly refused to eat foods that he had previously enjoyed, gagging and spitting them out… I am a nurse. My husband is a doctor. We would have never made a correlation between our son’s illnesses and vaccines. But in July 1999 I read that a preservative, thimerosal, utilized in some infant vaccines actually contained 49.6% ethylmercury… I quickly pulled out the thick file containing my son’s medical records. My worst fears were confirmed. All of my son’s early vaccines had contained thimerosal.”

She follows up with a picture of her child and a picture of a child with mercury poisoning. Go look at the post (or the picture) yourself if you want to see it. It’s not for scientific or educational purposes, so I refuse to violate the child’s privacy by posting his pictures openly online. She continues the post with a gross misunderstanding of pharmacokinetics, immunology, and toxicology. Frankly, if I were part of the graduating class that put forth this nurse, I’d be embarrassed.

All of her son’s vaccines had thimerosal? MMR and other live-virus vaccines don’t have thimerosal. Did the child not receive those? But I digress…

What really grinds my gears is that she is trying to convince her readers that her child has mercury poisoning because he looks like a mercury-poisoned child. To me, her child looks sleepy (and annoyed) more than suffering from mercury poisoning. Go and Google “sleepy face” and tell me if those are all mercury poisoned people. Is that what autism looks like? Not at all. Autistic children look all sorts of ways, and you’d be hard-pressed to identify an autistic child out of a line-up on physical traits alone.

Lyn finishes with this bit:

“When you talk with your representatives, please encourage them to pass legislation mandating the removal of mercury from all medical products and to put an end to this madness once and for all. And, finally, we need you to be savvy consumers and to just say no to any medical products, including vaccines, which contain mercury. I’ll be writing more about what you need to know about mercury in prescription drugs in the coming weeks, so check back soon. The pharmaceutical industry must heed our call. The government must start paying attention and start protecting our children. This should be a no-brainer. How could anyone possibly justify injecting mercury into a pregnant woman or small children? It’s time for the government to do its job. We need to stop putting poison in our children.”

Oh, good, I’ll have more to blog about.

When statistically significant is insignificant

I love Twitter. I got a hold of this little bit of anti-vax nonsense and just had to bring it to everyone’s attention. Check this out:


You can click on the image to see it a little larger. The original caption is what caught my eye. It reads: “Snapshot of the Verstraeten study dated 02/29/00 showing a statistically significant relationship between mercury exposure and autism.” My emphasis added in bold because this image shows no such thing. It shows a statistically insignificant relationship between mercury exposure and autism.

However, I realize that some of these terms might as well be in Chinese to some of you, unless you speak Chinese. So let’s break it down piece by piece.

Relative Risk (RR) is the ratio in the risk of developing autism given an exposure to thimerosal between a control and an intervention group. That’s the left-hand axis. The control group doesn’t get thimerosal. The intervention group does.

For example, if the RR is 10, then those exposed to thimerosal have a ten times higher risk of developing autism than those who were not exposed. An RR of 1 means that there is no difference in the risks; both exposed and unexposed have equal risks of developing autism. So, an RR of 1 means that the relationship observed is not statistically significant.

Statistical significance means that the results you observe are not due to random chance. That’s the 95% confidence interval (CI) part. That CI tells you the range of RR values you’d see 95 out of 100 times if you repeated the same experiment 100 times. The CI in this chart is represented by the error bars in each value.

At <37.5 micrograms, there was no difference between the two groups. The RR was 1. Note the lack of error bars for that value because of the low number of study subjects (n=5).

At 37.5 micrograms, the RR is still 1. Again, no difference.

At 50 micrograms, the RR is 0.93. This means that the control group is about 7% more likely to develop autism than the thimerosal group. BUT the CI includes 1, so there is a very good chance that your RR will be 1 if you repeat the experiment 100 times. As a result, this finding is not statistically significance. Certainly, I would not go out to the streets and proclaim that thimerosal protects from autism.

At 62.5 micrograms, the RR is 1.26, meaning that the group receiving thimerosal is 26% more likely to get autism than the control group. BUT look at the CI again! It still includes 1. As before, this result is statistically insignificant.

At over 62.5 micrograms, the RR rises to 2.48. The CI still includes 1. This result is statistically insignificant.

Wait! Doesn’t this show a trend whereby if the exposure is high enough, then the association will be stronger? Nope. It doesn’t. If you look at the error bars, you could hit 1.0 the whole time. Heck, with the logic shown in this article, I could make a case that thimerosal is protective against autism at certain levels.

It’s nonsense (to not use a harsher word).

But anti-vaccine advocates are not known for letting facts get in the way. The author of that piece of nonsense continues with quotes taken out of context from some meeting long used by anti-vaxers as evidence of a plot… Blah! Blah! Blah!

If you don’t know what is statistically significant and what is not, then that pretty much destroys your entire argument from the get-go. If you try to come off as a researcher, when you’re obviously not, then you lose the argument even worse.

But what about that study? Well, read all about it here, here, here, and here, and see how it has been misused to further the anti-vaccine agenda. Too bad they don’t know the difference between significant and insignificant, or they would have not used this study (or this graph).

Tuna sandwich, anyone?

I just ate a delicious tuna salad sandwich while sitting here at my office. It was delicious. Did I tell you how delicious it was? Part of me felt that I had done a good thing for my body by eating that tuna salad sandwich instead of a double cheeseburger with cheese and bacon. The other part of me remembered what’s in tuna. So here are some thoughts.

According to this Consumer Reports report, there’s a lot of mercury in tuna:

Fortunately, it’s easy to choose lowermercury fish that are also rich in healthful omega-3 fatty acids. That’s especially important for women who are pregnant or might become pregnant, nursing mothers, and young children, because fetuses and youngsters seem to face the most risk from methylmercury’s neurotoxic effects. 

Results from our tuna tests, conducted at an outside lab, underscore the longheld concern for those people. We found:

  • Every sample contained measurable levels of mercury, ranging from 0.018 to 0.774 parts per million. The Food and Drug Administration can take legal action to pull products containing 1 ppm or more from the market. (It never has, according to an FDA spokesman.) The EPA compiles fish advisories when state and local governments have found high contaminant levels in certain locally caught fish. 
  • Samples of white tuna had 0.217 to 0.774 ppm of mercury and averaged 0.427 ppm. By eating 2.5 ounces of any of the tested samples, a woman of childbearing age would exceed the daily mercury intake that the EPA considers safe. 
  • Samples of light tuna had 0.018 to 0.176 ppm and averaged 0.071 ppm. At that average, a woman of childbearing age eating 2.5 ounces would get less than the EPA’s limit, but for about half the tested samples, eating 5 ounces would exceed the limit.

That’s a lot of mercury, especially if you eat a lot of tuna. And you should be concerned about this mercury because it’s methylmercury. It does this funny thing called “bioaccumulation”. You don’t need to be a a rocket scientist to know that mercury accumulating in your body is not a good thing. Just ask this guy:
Did he have mercury poisoning?
The thing is, the anti-vaccine lobby keeps harping on mercury in vaccines causing autism. In their minds, the symptoms of mercury poisoning mimic the symptoms of autism. Ergo, autism must be mercury poisoning, right?
First of all, the compound used in childhood vaccines and since phased-out is thimerosal, an ethylmercury-containing compound. I’ve told you about the chemistry of these things, so there’s no need to beat that horse to death. The main gist of this blog post is to point out the following:
In fact, I’d venture to guess that it is much more biologically plausible — because of bioaccumulation of mercury — that tuna would cause autism IF AND ONLY IF autism was caused by mercury. The evidence for that has been put to rest.
Why, oh, why, the anti-vaccine lobby keeps going on and on and on about mercury in vaccines (when it’s been phased out) and don’t viciously attack tuna is beyond me.