Autism and Mercury
A recent study funded by the Centers for Disease Control and Prevention (CDC) in Atlanta claims that thimerosal, a mercury-based preservative used for many years in vaccines, is "not associated with problems in speech, intelligence, memory, coordination, attention, or other measures of childhood development." For those unaware of the thimerosal controversy, it has been claimed by many that it causes or is a factor in the development of autism. Michael Goldstein, vice president of the American Academy of Neurology said of the CDC study that it was, "enough to convince me that this small amount of mercury ... was not harmful to the children." However, there is a glaring problem with this study. While it seemed comprehensive with respect to thimerosal exposure, it apparently did so by combing health plan records, not by attempting to measure levels of mercury in the actual bodies of the children or their mothers during pregnancy. If thimerosal were the only possible source of mercury exposure, this might make sense. But we know that certain seafoods and dental fillings are suspect, not to mention potentially unrecognized sources that may exist. While the maximum amount of mercury obtained through thimerosal in vaccines may not by itself be enough to show statistical correlation with autism, it is still entirely possible that total exposure, including pre-natal, could. Additionally, with a high base level of mercury in some children, the addition of thimerosal into the mix might lead to toxicity. As we know from the study of many complex systems, including biological ones, non-linearity is the rule rather than the exception, and in particular, toxicity effects are often non-linear. This might partially explain why many parents of children with autism report noticing a marked acceleration of symptoms coincidental with vaccinations.