Mercury Is Rising – Again

The stories of Roman gods often seem timeless. Take Mercury—the god of commerce, communication, and, curiously, thieves. With his winged sandals and helmet, he zipped between worlds, overseeing the movement of goods, people, and ideas.

But Mercury wasn’t just swift—he was sneaky. In one myth, he steals a herd of cattle, bribes a man named Battus to stay quiet, then returns in disguise to test his loyalty. When Battus breaks his promise for a better bribe, Mercury turns him to stone.

Fast forward a few thousand years, and “Mercury” is making headlines again. Not the god this time, but thimerosal, a mercury-containing preservative once widely used in vaccines. And much like the ancient myths, today’s conversation around it is full of confusion, caution, and controversy.

What Is Thimerosal, Really?
Thimerosal is a mercury-based compound containing ethylmercury. It was first added to vaccines in the 1930s to prevent bacterial contamination—especially in multi-dose vials. At the time, it was a breakthrough. Before preservatives and the discovery of antibiotics, contaminated vaccines could—and sometimes did—cause life-threatening infections.

Methyl or Ethyl?
In the 1990s, concern about mercury surged. New research on a different form—methylmercury, known to harm developing brains—sparked widespread alarm. It’s found in certain fish like tuna and swordfish, builds up in the food chain, and accumulates in the body. That’s why pregnant women are often advised to limit seafood high in mercury.

Ethylmercury,—the type of mercury found in thimerosal—is processed quickly by the body and doesn’t build up over time. At the small amounts once used in vaccines, it has never been shown to harm the developing brain.

To put it in perspective: methylmercury and ethylmercury might sound alike, but they’re as different as methanol—the poisonous kind of alcohol used in antifreeze—and ethanol, the kind you’ll find in wine or beer. They might sound alike, but the way they act in the body couldn’t be more different.

On the Agenda 
Last week, Health and Human Services Secretary Robert F. Kennedy Jr.—a longtime vaccine critic—replaced all 17 members of the CDC’s vaccine advisory panel with eight new appointees, some have known anti-vaccine views.

First up on their agenda? A vote on flu vaccines that contain thimerosal.

Kennedy has long blamed thimerosal for a “silent epidemic” of autism—a claim he made in a 2014 book. But decades of research have debunked that theory. Some facts:

• Thimerosal was removed from U.S. childhood vaccines in 2001
• Measles, mumps, and rubella (MMR) vaccines do not and never did contain thimerosal.
• Chickenpox, inactivated polio (IPV), and pneumococcal conjugate vaccines never contained thimerosal.

More than 20 years of studies show no credible link between thimerosal and autism—or any brain-related harm. The science is clear, even if the myth still lingers, fueled by social media and the confusion between two very different types of mercury.

Trust in Science 
In Roman mythology, Mercury was swift and clever—but also tested trust. Today, in the world of vaccines, we’re facing a similar test. Reviving old fears about thimerosal—fears science has long laid to rest—puts decades of public health progress at risk.

Mercury turned Battus to stone for breaking his word. Likewise, we must hold our federal officials accountable to their word—no winged sandals required!

Happy reading,

Suzanne Daniels

Enjoy the weekend!

Best,
Suzanne
Suzanne Daniels, Ph.D.
AEPC President
P.O. Box 1416
Birmingham, MI 48012
Office: (248) 792-2187
Email: [email protected]

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