One of the proposed links between Mercury and Autism is Thimerosal, a compound that has been used in vaccinations. A new study [PDF of abstract] from the University of Washington, Seattle, USA has examine the different effects of ethyl mercury, used in Thimerosal, and methyl mercury, commonly used in industrial processes. Most of the toxicology data on mercury is based on accidental exposure to Methyl Mercury in the work place.
The study inject new born monkeys with either ethyl mercury (in the form of thimerosal) or methyl mercury in doses equivalent to that found in vaccinations for human babies. Mercury levels were then monitored and it was found that the ethyl mercury cleared from the body a lot quicker than the methyl mercury. Critically brain concentrations of total mercury were significantly lower by about three-fold for the thimerosal exposed infants when compared to the methyl mercury infants. This is important because mercury causes brain damage only through long-term exposure (a fact that gave us the phrase ‘as mad as a hatter‘). Thus if the body is cleaning itself quickly of the ethyl mercury, it doesn’t have the chance to build up and cause damage.
Coverage from Rueters: Mercury in Vaccines Different, Study Shows