At a party I was at on Saturday night, there was an interesting discussion with the social workers & special ed teachers in attendance about the seemingly huge rise in Autism. Everyone conceded that it may be due in part to the Autism spectrum vastly widening with the PDD diagnosises. It does seem to be everywhere now --so many people you meet have an autistic sibling or child, yet I can't think of anyone I knew of that had Autism before I was 18.
I know that anti-vaccine crowd looks to blame it on that, but if your kids don't get vaccinated they don't go to school. My kids have had all the required vaccines (and even a few experimental ones that they no longer give) and neither have autism --nor do any of my friend's vaccinated children... Mercury in vaccines causing autism has pretty much been ruled out anyway. There has to be a cause though...
One thing that's comforting is researchers always seem to be coming up with new theories:
"Samples from children with autism contained abnormally high levels of a family of proteins called porphyrins, which are precursors in the production of haem, the oxygen-carrying component in haemoglobin. Heavy metals block haem production, causing porphyrins to accumulate in urine. Concentrations of one molecule, coproporphyrin, were 2.6 times as high in urine from children with autism as in controls.
Autism is thought to have a number of unknown genetic and environmental causes. Richard Lathe of Pieta Research in Edinburgh, UK, says he has found one of these factors. "It's highly likely that heavy metals are responsible for childhood autistic disorder in a majority of cases," he claims. The study will appear in Toxicology and Applied Pharmacology." (source)