The U.S. Environmental Protection Agency (EPA) and U.S. Food and Drug Administration (FDA) once again advised pregnant women to curb consumption of fish in order to limit fetal exposures to neurotoxic mercury. This warning raises the baffling query: How can the Centers for Disease Control and Prevention (CDC) justify its recommendations that pregnant women get flu shots which are laden with far more mercury than what's found in a can of tuna?

The CDC has long answered that nettlesome question with the controversial claim that ethylmercury in vaccines is not toxic to humans. Now, two CDC scientists have published research decisively debunking that assertion. As it turns out, there is no "good mercury" and "bad mercury." Both forms are equally poisonous to the brain.

The CDC study, Alkyl Mercury-Induced Toxicity: Multiple Mechanisms of Action, appeared last month in the journal, Reviews of Environmental Contamination and Toxicology. The 45-page meta-review of relevant science examines the various ways that mercury harms the human body. Its authors, John F. Risher, PhD, and Pamela Tucker, MD, are researchers in the CDC's Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry.

"This scientific paper is the one of most important pieces of research to come out of the CDC in a decade," Paul Thomas, M.D., a Dartmouth-trained pediatrician who has been practicing medicine for 30 years, said. "It confirms what so many already suspected: that public health officials have been making a terrible mistake in recommending that we expose babies and pregnant women to this neurotoxin. I regret to say that I gave these shots to children. The CDC led us all to believe that it was perfectly safe."

Among the findings of the CDC's new study:

  • Methylmercury, the highly-regulated neurotoxin found in fish, and ethylmercury (found in medical products, including influenza and tetanus vaccines, ear drops and nasal sprays) are similarly toxic to humans. Methylmercury and ethylmercury share common chemical properties, and both significantly disrupt central nervous system development and function.
  • Thimerosal is extremely toxic at very low exposures and is more damaging than methylmercury in some studies. For example, ethylmercury is even more destructive to the mitochondria in cells than methylmercury.
  • The ethylmercury in thimerosal does not leave the body quickly as the CDC once claimed, but is metabolized into highly neurotoxic forms.

Despite this stark rejection of a decade of CDC safety assurances, CDC's public relations machine is still bucking the new scientific consensus; the article concludes with a telling disclaimer in tiny font:

"The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Agency for Toxic Substances and Disease Registry."

CDC's website continues to feature now discredited safety assurances.

"Baldly dismissing the danger to humans from ethylmercury, has long been a reckless gambit," said J.B. Handley, a Portland, Oregon, businessman who believes that his son received debilitating injuries from a mercury vaccine. "With this study, by its own scientists, the CDC has now edged into the realm of criminal endangerment."

Handley, the founder of Generation Rescue, a vaccine safety advocacy group, condemns the CDC for misleading the medical establishment.

"The CDC knows that pediatricians and physicians rely on its public pronouncements when they make treatment decisions for their patients; how can we escape the conclusion that the agency is knowingly causing the poisoning of tens of millions of American children," Handley stated.

For example, CDC's webpage still parrots the now discredited industry canard that:

"Thimerosal contains ethylmercury, which is cleared from the human body more quickly than methylmercury, and is therefore less likely to cause any harm."

However, the new study makes the opposite conclusion:

"Thimerosal is quickly metabolized in vivo (in a living organism) due to its reactions with protein and non-protein thiols … so the effects of thimerosal reported in numerous articles are very likely the result of exposure to the metabolite ethylmercury."

Ignoring the agency's own scientific evidence, the CDC's webpage stubbornly insists that the "two types of mercury to which people may be exposed—methylmercury and ethylmercury—are very different." The new CDC study directly contradicts this assertion, "There are many commonalities/similarities in the mechanisms of toxic action of methylmercury and ethylmercury …"

The study meticulously details identical toxicity pathways shared by both forms of mercury:

  • Both ethyl and methyl mercury cause DNA damage or impair DNA synthesis (Burke et al. 2006; Sharpe et al. 2012; Wu et al. 2008).
  • Both cause oxidative stress/creation of reactive oxygen species (Dreiem and Seegal 2007; Garg and Chang 2006; Myhre et al. 2003; Sharpe et al. 2012; Yin et al. 2007).
  • Both decrease glutathione activity, thus providing less protection from the oxidative stress caused by MeHg and EtHg (Carocci et al. 2014; Ndountse and Chan (2008); Choi et al. 1996; Franco et al. 2006; Mori et al. 2007; Muller et al. 2001; Ndountse and Chan 2008; Wu et al. 2008).
  • Both cause effects on cell division by damaging the spindle apparatus during mitosis (Burke et al. 2006; Castoldi et al. 2000; Gribble et al. 2005; Kim et al. 2007; Ou et al. 1999b; Machaty et al. 1999; Rodier et al. 1984).
  • Both MeHg and EtHg bind to the amino acid cysteine (Clarkson 1995; Wu et al. 2008).
  • Both MeHg and EtHg strongly inhibit the reacylation of arachidonic acid, thus inhibiting the reincorporation of this fatty acid into membrane phospholipids (Shanker et al. 2002; Verity et al. 1994; Zarini et al. 2006).
  • Both cause an increase in NOS, causing an overproduction of NO (Chen et al. 2003; Chuu et al. 2001; Shinyashiki et al. 1998).
  • Both disrupt glutamate homeostasis (Farina et al. 2003a, b; Manfroi et al. 2004; Mutkus et al. 2005; Yin et al. 2007).
  • Both alter intracellular calcium homeostasis (Elferink 1999; Hare et al. 1993;Kang et al. 2006; Limke et al. 2004b; Machaty et al. 1999; Marty and Atchison1997; Minnema et al. 1987; Peng et al. 2002; Sayers et al. 1993; Sirois and Atchison, 2000; Szalai et al. 1999; Tornquist et al. 1999; Zarini et al. 2006).
  • Both cause effects on receptor binding/neurotransmitter release involving one or more transmitters (Basu et al. 2008; Coccini et al. 2000; Cooper et al. 2003; Fonfria et al. 2001; Ida-Eto et al. 2011; Ndountse and Chan 2008; Yuan and Atchison 2003).

"This study is a nuclear bomb detonating over the CDC," Boyd Haley, chairman emeritus of the University of Kentucky Chemistry Department, said. "It should be getting international, front page headlines."

As one of the world's leading authorities on mercury toxicity, Haley observed, "It's a momentous rejection of a widely held medical orthodoxy dictating policy changes even more significant than the medical establishment's reversals on thalidomide, calomel tooth powder, x-rays during pregnancy, or lead exposure to children. In each of these cases, thousands of children were injured or killed before an entrenched medical establishment was finally willing to abandon treatments that were unquestionably causing great harm."

Next Page