Seeking Reasons For Autism's Rise in L.A.?

Why is a child born in northwest Los Angeles four times as likely to be diagnosed with autism as a child born elsewhere in California?
Medical experts have pondered for years why autism rates have soared nationwide, and why the disorder appears to be much more prevalent in certain communities than in others. Now, some recent studies that zero in on California may shed some light on these baffling questions.
Researchers from Columbia University, in a study published in the current Journal of Health & Place, identified an area including West Hollywood, Beverly Hills and some less posh neighborhoods that accounted for 3% of the state's new cases of autism every year from 1993 to 2001, even though it had only 1% of the population.