Mercury exposure triggers autism?
That hypothesis is starting to smell a little fishy...
Austic children may actually have lower levels of mercury in their blood. Why? Probably because they're pickier eaters and thus eat less fish according to a new study published online at the journal Environmental Health Perspectives. Researchers at the University of California, Davis found no differences in mercury levels between children with autistic diagnoses and those without (including children with other developmental delays)- after controlling for how much fish they ate. It's a pretty large, well-controlled observational study.
This is one more piece of evidence shedding doubt on a mercury-autism link. Is a link possible? Certainly, this research examined post-diagnosis blood levels, it does not say a thing about the causal role of mercury. It's possible prior mercury exposure is a factor. Could autistic children somehow be more sensitive to mercury? Possibly. But it looks they have no more mercury circulating in their blood than other children.