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Thimerosal: Let the Science Speak

The Evidence Supporting the Immediate Removal of Mercury--a Known Neurotoxin--from Vaccines

Edited by Robert F. Kennedy Jr. / Introduction by Martha Herbert / Preface by Mark Hyman
Published by Skyhorse
Distributed by Simon & Schuster

About The Book

From New York Times bestselling author Robert F. Kennedy, Jr., comes a science-based call for the immediate removal of the dangerous mercury-containing preservative Thimerosal from vaccines.

Over a decade ago, following a sharp rise in developmental disorders such as autism and ADHD, the mercury-containing preservative Thimerosal was widely believed to have been eliminated from vaccine supplies in the United States and abroad. However, dangerous quantities of Thimerosal continue to be used, posing a significant threat to public health and leading to a crisis of faith in vaccine safety.

In this groundbreaking book, Robert F. Kennedy, Jr., examines the research literature on Thimerosal and makes a very clear statement about its potentially dangerous effects. In the past, the CDC, FDA, NIH, and AAP, as well as the US Congress, the American Academy of Family Physicians, the US Department of Agriculture, the European Medicines Agency, and the California Environmental Protection Agency have expressed concerns over the use of Thimerosal in vaccines. But despite the many voices calling for action, the media and policy makers have repeatedly failed to adequately address the issue.

Now, with Thimerosal: Let the Science Speak, the science supporting the elimination of this toxic chemical from the world’s vaccine supplies, and its replacement with already available safer alternatives, is all in one place. Making this change should increase vaccination rates by restoring the trust of concerned parents in the vaccine program—a program that is so vitally important to public health.



Many years before my term in Congress I questioned the wisdom of injecting the mercury-based vaccine additive, Thimerosal, into children and pregnant women. When I was elected to Congress in 2008, I came to find that my predecessor, Congressman Dave Weldon, a medical doctor, shared this concern. Through working with like-minded individuals, including Mr. Robert F. Kennedy, Jr., I quickly became aware of an enduring concern among researchers, doctors, and loving parents about vaccine safety in the US and around the world. It is common sense that injecting infants with a mercury compound exposes them unnecessarily to risk.

This book is resolutely pro-vaccine and is far too valuable to be shrouded by the polarizing pro-vaccine versus anti-vaccine debate. The late 18th century work of Edward Jenner and Benjamin Waterhouse in bringing the first smallpox vaccine to the American public will be forever honored. In the same way, the contemporary work of those who introduce innovative and life-saving treatments, including vaccines, will also be remembered. This book is about making vaccines safer. Like the work of Jenner and Waterhouse, it advocates for health and wellbeing, and does so through a foundation of scientific facts and research.

Hundreds of parents from across the country have contacted me in recent years, describing their children as developing normally up to the time of receiving a particular vaccination. While the large majority of children do not have adverse reactions, we acknowledge that some children do react severely and have established a compensation program to provide for their care.

In 1999, after acknowledging that the public health community failed to do simple addition to know how much mercury-based Thimerosal young infants were receiving, the American Academy of Pediatrics (AAP) and the United States Public Health Service (USPHS) agencies recommended that Thimerosal be reduced or eliminated from vaccines. Between 1999 and 2003, Thimerosal was phased out of all routine pediatric vaccines administered in the United States. This was much welcomed and by early 2004 only small trace amounts of mercury remained in routine childhood vaccines.

In a seemingly inconceivable reversal, however, in 2004 the Centers for Disease Control and Prevention (CDC) recommended that certain infants receive the annual flu vaccine—most of which contained Thimerosal. Over the next decade the CDC’s annual flu vaccine recommendations were expanded to include annual flu vaccines for infants, children, adults, and the aged. This is a significant reversal of the positive steps taken between 1999 and 2003. Had the post-2004 CDC recommendations not been taken, this book would perhaps not be necessary for the American public. (Thimerosal continues to be used throughout most of the developing world as the predominant vaccine preservative.)

The continued use of mercury, a known neurotoxin, raises particular concern for populations that are most vulnerable to neurodevelopmental harms, mainly a fetus in utero, infants, young children and the aged. When we speak of the health and safety of our children, our future generation, we speak of a societal responsibility, which we are privileged to bear.

In 2004, the Institute of Medicine (IOM) published a report refuting any link between exposure to Thimerosal and autism. This report relied heavily on several epidemiological studies, which have been criticized for involving conflicts of interest. These studies examined populations of children that were increasingly exposed to Thimerosal throughout the 1990s. Likewise, the prevalence of neurodevelopmental disorders, including autism, soared from 1 in 2,000 in the 1980s to 1 in 166 by the early 2000s. This book does not claim that Thimerosal is the only factor in these alarming prevalence rates. It does, however, call for commonsense recognition of the possible role this neurotoxin may have played in the sudden rise in the spectrum of neurodevelopmental disorders.

During the writing of this book, I was approached by a CDC researcher who felt personally led to expose instances of research misconduct within the CDC, particularly with regard to a 2004 Pediatrics article, Age at First Measles-Mumps-Rubella Vaccination in Children With Autism and School-matched Control Subjects: A Population-Based Study in Metropolitan Atlanta. As this book discloses, this is not the first instance of CDC conduct to come under scrutiny. Regrettably, studies on the relationship between vaccines and autism have been subject to misconduct including data manipulation and false reporting.

Many of the CDC’s own studies have demonstrated a link between increased Thimerosal exposures and the development of vocal and motor tics, which are generally recognized as autism-like features. This alarming association has been downplayed to the public. Sadly, public health agencies’ insistence on Thimerosal’s safety has effectively inhibited objective investigations into research misconduct and conflicts of interest within health agencies and the vaccine industry.

I’m from the “Sunshine State” and believe that sunlight is the greatest disinfectant. In this book, Robert F. Kennedy, Jr. clearly sets forth the unvarnished truth on Thimerosal.

Benjamin Franklin once said, “Being ignorant is not so much a shame, as being unwilling to learn.” With regard to Thimerosal in childhood vaccines, we have yet to heed Mr. Franklin’s words. After reading this book, I hope you will join us in the battle to make vaccines safer for all.

US Congressman Bill Posey



Vaccinations are among the most important advances in medicine in the last century. We have eradicated smallpox from the planet and dramatically reduced death and suffering from infectious disease around the globe.

I am aggressively pro-vaccine, as are the editor and introduction contributor of this book. I am a father and family physician. I have vaccinated my children. I have been vaccinated and recommend vaccination to my patients.

Critics of this book will quickly polarize the debate. It is easy to oversimplify the issue of Thimerosal into pro-vaccine or anti-vaccine, or to confuse this issue by debating whether Thimerosal causes autism, which has not been definitively proven. This is unfortunate, and detracts from a much simpler set of questions that are ultimately the subject of this scientifically dense book.

There is no debate that mercury in any form is toxic. Scientists may debate the differences in toxicity between different forms of mercury, such as ethylmercury (which is an ingredient in Thimerosal) or methylmercury (from fish). But all would agree that mercury is a potent neurotoxin.

There is also no debate about the dramatic increase in prevalence of neurodevelopmental disorders, over the last few decades, including learning disabilities, attention deficit disorders, and autism.

There may, however, be debate on the strength of the data and science implicating mercury in this increased prevalence of brain injury in children. These questions can never be adequately answered given the challenges of doing experimental studies on human subjects over long periods of time. Obviously, no ethical review board would ever approve a study in which children were purposefully exposed to mercury in order to test its toxicity. Population studies show correlations, but never prove causation, making it impossible to draw firm conclusions.

That leaves us with a very simple, moral question, and ultimately a very personal one. Because at some point in our lives, nearly all of us will have a child or grandchild who requires vaccinations. Or we will know a pregnant woman who will have to decide whether or not to get a flu shot that might contain mercury. All of us are people and parents first, and scientists and policy makers second.

So there is only one question that really matters:

Would you expose the unborn child or infant of a loved one to a vaccine containing mercury, a known neurotoxin, if there were other safer alternatives?

The answer to this question is simply common sense and requires no further scientific inquiry, but as Voltaire said, “common sense is not so common.”

If there were no other options, if it were a question of whether to vaccinate or not to vaccinate, then of course we would choose vaccination. But that is a false choice. There are 137 million children born each year in the world. Is our only option to subject them to a potent neurotoxin in their most delicate neurodevelopmental period? How can we best protect that future generation from preventable harm?

The arguments put forth that we cannot remove Thimerosal from vaccines are invalid. Thimerosal has already been removed from nearly all vaccines except the multidose flu vaccine in the United States. This was based on government recommendations and a call to action from many agencies and health organizations, as is well documented in this book.

However, Thimerosal still remains in nearly all the pediatric vaccines used in the developing world. There are effective alternative preservatives already in use (2-phenoxyethanol), and new ones can be developed. The Food and Drug Administration (FDA) banned mercury as a topical antiseptic (remember Mercurochrome?). And any medical products containing Thimerosal or mercury cannot be thrown in the garbage. The Environmental Protection Agency (EPA) considers them hazardous waste. Does it make any sense that even though Thimerosal is not safe to put on your skin, or to throw in the garbage, it is safe to inject into pregnant women and babies?

Cost considerations are also used as an argument to keep Thimerosal in vaccines. There is a small cost increase to use single-dose flu vaccines, but it is minor compared to the cost of neurodevelopmental disease in children. The global cost of taking Thimerosal out of all vaccines is $300 million a year, while the annual cost of autism in the United States alone is well over $100 billion. In the developing world, studies show that there is significant wastage of multidose vials, making single-dose vials comparable in cost.

There are other arguments. Some scientists we spoke to at the Department of Health and Human Services said that Thimerosal may contribute to the effectiveness of the vaccines. Any agent that increases vaccine effectiveness is referred to as an adjuvant. However, Thimerosal is approved for use only as a preservative, not as an active ingredient, and such use is illegal.

I have been involved in reviewing and contributing ideas and scientific references to this manuscript. I have also been involved in efforts to change regulatory and legislative policy to reduce potential harm from Thimerosal. I do not belong to any organization connected in any way with this issue. Nor do I have any personal or financial interest in this issue other than a scientific and moral one.

And, as a physician, my Hippocratic oath is to “first, do no harm.” We should practice the precautionary principle in medicine and avoid doing harm whenever possible. And given the simple fact that mercury is toxic, I can come to no other conclusion than this: we should immediately remove Thimerosal from vaccines and all other products used in medicine.

Mark Hyman, MD
West Stockbridge, Massachusetts
June 7, 2014

Product Details

  • Publisher: Skyhorse (August 4, 2014)
  • Length: 224 pages
  • ISBN13: 9781632206015

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