Though this paper talks about non-mental physical environmental factors, I consider mental environmental factors playing critical role.
Key environmental factor is Family life. Kids growing under nuclear setup, working parents, with relatively less social interaction are prone to एकांगी विकास (Autism).
Kids need, not only mother and father. They need grandparents, uncles, aunties, friends of parents, friends of grandparents for balanced mental development.
Take care. Autism is growing endemic. Save your kids. Be social (Not here!) in real life. Meet friends regularly. Meet relatives regularly. Live in joint family if possible.
Study Shows Environmental Influences May Cause Autism in Some Cases
“Although much more work is needed, our study reveals a plausible way that environmental influences—which we know are important in ASD—might be exerting their effects.” — John Greally, M.B.,B.Ch., Ph.D.
– See more at: http://www.einstein.yu.edu/news/releases/1011/study-shows-environmental-influences-may-cause-autism-in-some-cases/#sthash.EsC0RUlv.dpuf