An article by Harvey Karp, MD appeared in the Huffington Post on June 30 about the latest research theories about the upswing in autism.  It may not be about immunizations and mercury after all.  This article offers plausible theories that seem quite reasonable. He discuss's  ubiquitous family of hormone twisting compounds, known as  EDCs ( endocrine disrupting chemicals) which are found in Teflon, plastics, and formaldehyde

"Our increasing exposure to EDCs ( endocrine disrupting chemicals)  lends support to a new hypothesis about the cause of autism, called the "extreme male theory." This theory, proposed by Dr. Simon Baron-Cohen and colleagues, speculates that autism is caused by something changing a fetus' hormonal balance that then leads to over-masculinization of the developing brain   tinyurl.com/lsnqhb