A major study was done over several years comparing the autism rates amongst women who were living near freeways during pregnancy versus those who were not.
What this particular study shows is a strong possibility of a link to high levels of air pollution increasing the rates of autism. Again this is another “environmental factor” though this particular study does not look at genetic possibilities as an additional factor other testing makes it likely that genetics as well was a factor.
In comparison to thethis provides an additional environmental factor to include in addition to illnesses and parasites and in addition to other various environmental factors that have been suggested in the past including pesticides, pet shampoos and toxins from coal burning plants.
My personal conclusion from this as well as various studies that have found differing genetic links to autism is this:
Autism is likely caused by a combination of various genetic mutations working in concert with various illnesses and toxins introduced both during the mothers pregnancy and at various points after birth.
I do not believe we will ever pinpoint a singular cause for “all” autistic individuals and as such believe that it is highly likely that the cures and treatments for autism will stretch across a broad spectrum because of these variations.
I do not believe any particular “environmental factor” can be completely ruled out until all genetic variations linked to autism are identified and then matching them to possible environmental factors in specific autism cases.
In all i would love to see this study duplicated to back up the results seen here however i do believe the results are relevant to the situation