Autism: Traffic pollution linked, study suggests

The possibility that autism is linked to traffic pollution has been raised by researchers in California.

Their study of more than 500 children said those exposed to high levels of pollution were three times more likely to have autism than children who grew up with cleaner air.

However, other researchers said traffic was a "very unlikely" and unconvincing explanation for autism.

The findings were presented in the Archives of General Psychiatry journal.

Data from the US Environmental Protection Agency were used to work out levels of pollution for addresses in California.