Set to be published in the American Journal of Pediatrics is another study that refutes the notion that thimerosal causes autism. You may remember that a little while ago, a study done by the Department of Health in California suggested that there was no link because in that state, thimerosal has not been used in routine vaccinations since the early ’90’s, yet the autism rate has continued to increase steadily rather than decrease; which is what you’d expect to see if there were a strong link.
Some Background
Thimerosal is mercury that is used as a preservative in vaccinations. Fears over it’s use arose late in the 90’s when it was found that a child who received a full series of vaccinations would potentially receive up to 187.5 grams of ethyl mercury during the first six months of life. The EPA reported however, that the safe amount of intake for ethyl mercury is .1 grams per pound.
In addition, if you talk to many autism advocacy groups, numerous parents swear that there is a connection. You can hear story after story of children that started showing symptoms shortly after their vaccinations.
The Newest Study
What I find interesting about the newest study is that it actually tests the half life of intramuscular ethyl mercury rather than looking at individual people and cases. While looking at individual cases has its value, it also has lots of variables that are nearly impossible to rule out.
What scientists in this study, conducted at the University of Rochester, found is that the half life* of intramuscular ethyl mercury is different than the half life of oral ethyl mercury (like what you might ingest from eating fish). If you ingest mercury in fish let’s say, the half life is 44 days. That’s how long it takes for half of the mercury to leave your system.
Conversely, when it’s injected in a vaccine, the half-life of mercury is 3.7 days. Researchers are suggesting that this is simply not enough time for toxicity to build up. While this certainly is encouraging information, what I’d like to see is new guildelines based on this new information.
However, thimerosal is not widely used in the United States in childhood vaccines any longer. If you want to know if your child’s vaccines have thimerosal or if you want to make sure they are thimerosal free, simply ask your pediatrician.
*half life is the time it takes half of a substance to leave your body
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