Skeptoid PodcastSkeptoid on Facebook   Skeptoid on Twitter   Skeptoid on Stitcher   Skeptoid on Spotify   iTunes   Google Play

Members Portal

Support Us Store


Get a Free Book



Robert F. Kennedy, Jr, Vaccines, and Mercury

by Stephen Propatier

August 8, 2015

Share Tweet Reddit

Donate I recently received a copy of Robert Fitzgerald Kennedy, Junior's new book, titled Thimerosal: Let the Science Speak (Skyhorse Publishing, 2015), which is dramatically subtitled The evidence supporting the immediate removal of mercury—a known neurotoxin—from vaccines. My first impression was one of confusion over the title, since the book is written in English and almost no English-speaking countries use thimerosal in any vaccines. The only exception is a limited number of flu vaccines, which are not generally used on children. RFK Jr has a long history of environmental activism, including fighting against industrial mercury pollution. He has a more recent track record of objecting to the vaccine preservative thimerosal—almost an obsession with the topic. He has been very vocal on talk shows and on Capitol Hill of late. Given the author, who is credited as "editor," I was not surprised by the subject matter. What caught my eye was the subtitle "let the science speak," an ironic statement to say the least. The book is a short, well-written redress of a completely inaccurate meme: namely, that vaccines cause autism or autism spectrum disorder (ASD). It is a unique tract on the subject. Another whole book could be written on the inaccuracies in this book, I will try to limit the issues to the overriding theme. Let's take a look at the book, its themes, and its implied (yet denied) purpose.

The most interesting thing about this book is the regular insistence that it is not about vaccines. The forward by Dr. Mark Hyman MD is a five-page statement of how this book is pro-vaccine and the only issue is the pharmaceutical industry and the additive thimerosal. It's a good way to present a scientifically unsupported idea to the lay public. By proposing that you really support the treatment and are just trying to fix this one small problem it is very disarming and effective to the casual reader. A reader may just be curious. Set a reasonable tone and make your progression to the unreasonable more compelling. It's very slick and very effective but openly deceptive. If you're pro-vaccine, you don't systematically give the impression that thimerosal is in wide use, that thimerosal is threatening, and that vaccine producers conspire with government to poison children—all without evidence.

If you're pro-vaccine, you don't include a preface written by a well-know medical fringe doctor, given the veneer of authority by the MD appended to his name. Dr. Hyman is physician who has many unsupported thoughts about autism, and a cottage industry called "Functional Medicine." I highly recommend David Gorski's Orac blogpost/treatise on Dr. Hyman.

Additionally, if you're pro-vaccine you don't have an introduction by Dr. Martha R. Herbert MD, a regular keynote speaker at most anti-vaccine conferences. Dr. Herbert had proposed a multitude unsupported and fringe mechanisms for autism. She has testified in court that "potential environmental triggers under active debate and research" for autism included "mercury, intrauterine viral infections, season of birth, global positioning, and water pollution," none of which are supported. GPS is giving your child autism. Maintaining an unscientific fringe opposition does not constitute "active debate and research." She is a supporter of the dangerous and useless practice of chelation therapy for autism.

The bottom line is that these are not the people you would ask to do your introductions if you were writing a pro-vaccine book. The opening lets your know exactly where this is going and what the real point is.

Kennedy proposes a common and tired anti-vaccine theme in his book: mercury is a neurotoxin, thimerosal contains mercury, and therefore vaccines that contain thimerosal are neurologically damaging children.

The book does scientific backflips to make this point, trying to fit a square peg in a round hole. Theres tons of listed research showing how mercury is dangerous. Other research attempting to show reasonable yet unproven theories why thimerosal's ethylmercury is the same as methymercury exposure. Yet it isn't.

From The CDC (one of Kennedy's bogeymen):
  • When learning about thimerosal and mercury it is important to understand the difference between two different compounds that contain mercury: ethylmercury and methylmercury. They are totally different materials.

  • Methylmercury is formed in the environment when mercury metal is present. If this material is found in the body, it is usually the result of eating some types of fish or other food. High amounts of methylmercury can harm the nervous system. This has been found in studies of some populations that have long-term exposure to methylmercury in foods at levels that are far higher than the U.S. population. In the United States, federal guidelines keep as much methylmercury as possible out of the environment and food, but over a lifetime, everyone is exposed to some methylmercury.

  • Ethylmercury is formed when the body breaks down thimerosal. The body uses ethylmercury differently than methylmercury; ethylmercury is broken down and clears out of the blood more quickly. Low-level ethylmercury exposures from vaccines are very different from long-term methylmercury exposures, since the ethylmercury does not stay in the body.

Even if you deny what the CDC is saying, as the authors do, and try to say that ethylmercury could be retained as methyl, it still just doesn't have the autism effect the authors imply. This has been unequivocally proven by thimerosal's complete removal from the vaccine schedule in 2002. As previously noted, it now remains only in some flu vaccines not given to children. The total dose of thimerosal exposure is far below 1990 levels. Children at that time were receiving vaccines with thimerosal well before before ASD diagnoses began to rise. Despite predictions by anti-vaccination proponents that ASD rates would fall dramatically in the years following the removal of thimerosal, the rate at which the disorder is diagnosed continues to rise, without even the slightest change in the rate of increase. This effect has been replicated in other countries. If you read data as sloppily as the anti-vaccine advocates do, you could argue that reducing thimerosal exposure actually caused the incidence of autism to go up. That correlation (not causation) is more strongly supported by evidence than the one suggesting the opposite effect. But it's just as specious.

Children just aren't given thimerosal in the vaccines they receive. The only US vaccine left with thimerosal is Fluvirin from Noventis (<1ug Hg/0.5mL dose). It is only given to adults. You inhale more mercury from air pollution than you get from that dose. Children don't get injectable flu vaccine for the most part. Nasal administration of attenuated flu vaccine is the common practice for children, not injectable, it has no thimerosal. If a child has to have the injectable form for some medical reason, there are versions with no thimerosal. This is fear mongering built on myth.

Thimerosal wasn't removed because of a proven problem. The evidence is that thimerosal was, and probably is, completely safe in vaccines. It was removed on the precautionary principle. Time and data supports the idea that its removal was unnecessary from a risk standpoint. It was that abundance of caution which caused removal. The removal is the foundation to the continuing ideology that thimerosal, and therefore vaccination, is somehow very dangerous.

The real answer to thimerosal is that there is no correlation between autism and vaccines, but the data does expose the authors' bias, especially since they work hard to dismiss obvious flaws in their arguments. With an unfounded yet plausible-sounding, medically inaccurate hypothesis, they try to lead readers to draw the conclusion that thimerosal is a threat. Kennedy impressively adds reams of footnoted research, trying to support the idea that there is a ton of evidence for this idea. He is missing the point.

This book is focusing on a non-issue that just doesn't exist in most English-speaking countries. Early in the book he talks about the 2002 removal of thimerosal in order to support the idea that it is a problem. He then proceeds to insist it is still a problem, which exposes clearly his lack of congruent thinking about this issue. The truth is that in poor countries without good medical infrastructure, thimerosal is still used because single-use, short-shelf-life doses of vaccine are not practical and damage the usefulness of the treatment. Thimerosal is an excellent and safe preservative, and is really effective, giving more people a chance to be spared debilitating or life-threatening diseases. Interestingly, those countries that still use thimerosal have the lowest rates of ASD over the last 10 years.

Kennedy counters this by saying that those environments lack the medical infrastructure to diagnose the condition. True, but mounting evidence shows that the increase in autism in the west is because of medical pursuit of the diagnosis.

There have been persistent concerns during the so-called "autism epidemic" that the increasing ASD rates are more a function of looking for it, rather than it truly being a increase. New research strongly supports this hypothesis. Kennedy couldn't have possibly known this when he wrote the book, since the research was only recently published, but it clearly shows that increasing surveillance and diagnostic criteria as the cause for the increase in autism spectrum disorder. I am fairly certain that this bit of evidence will not be the tipping point for Kennedy's opinion. 13 years after thimerosal was removed from US vacccines, the quixotic anti-vaccine crusade hasn't been derailed at all.

It is not science that guides the misinformation in this book. It is ideology: the unwavering misinformation that vaccines somehow directly link with a multitude pediatric neurological disorders. The author and other anti-vaccine proponents try to retain this argument by claiming that environmental exposure or some other outside mechanism is the reason why ASD is still going up. Kennedy offers an avalanche of data showing increasing neurological disorders, and research supporting mercury toxicity. But, despite his efforts to hold these two facts side-by-side, he is unable to show any link between the two problems. He and his coauthors are just plain wrong; science does not work that way. Scientific evaluation is the best way to evaluate medical risk and effectiveness. If your data shows no correlation then there is no correlation. If your hypothesis is that thimerosal causes autism, and after removing thimerosal from vaccines autism continues to increase, you have eliminated that as a possibility. You don't try to make excuses, or come up with other more elaborate and implausible reasons why it still must be true. That is not "letting the science speak." That is silencing science with ideology. It's shameful.

Take a minute and support Skeptoid. The money doesn't go to me, but instead goes to keep Skeptoid running as a resource of science and skepticism. Remember: all donations and gifts to Skeptoid Media, Inc. are tax deductible under section 501(c)(3) of the Internal Revenue Code (sections 170, 2055, 2106, 2522).

You can follow me at Twitter @steveproacnp for a daily dose of skeptical nursing. Please check out the completion of the series Occ: The Skeptical Caveman, which I helped produce with the guys at The Skeptics Guide To the Universe.

Disclaimer: This post is my personal opinion, it is not a substitute for medical care. It is for informational purposes only. The information on Skeptoid blog is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. This post does not reflect the opinion of my partners, professional affiliates, or academic affiliations. I have no financial conflicts of interest to disclose.

by Stephen Propatier

Share Tweet Reddit

@Skeptoid Media, a 501(c)(3) nonprofit








Want more great stuff like this?

Let us email you a link to each week's new episode. Cancel at any time: