Autism, or more accurately Autism Spectrum Disorder (ASD), is in the news and public view a lot in recent years. According to some recent reports, it is now diagnosed in 1 out of 68 children (1.47%) in the U.S. Reasons for the apparent increase in diagnoses over recent decades are complex, but they lead us to wonder what is happening and what are the causes?
Recent scientific literature suggests that the specific causes are largely unknown, but there is a very strong genetic component (heritability of 80%). Unfortunately, even the genetic aspects are very uncertain and probably highly complex, not just a simple set of genes like the ones that determine your eye colour. Although genetics may play a large role, there are also indications that environmental factors are involved, perhaps in some sort of interaction with the genetic factors.
The popular and social media keep going in circles about vaccines, a factor for which there is no reliable scientific evidence at all. At the same time, there seems to be complete ignorance of a growing body of scientific literature linking ASD with air quality. A quick search through peer-reviewed scientific literature using the Scopus database shows at least 160 papers that mention “autism and ‘air pollution'” somewhere in the publication over the past 20 years.
I don’t know a lot about ASD, but I can comment on air pollution and so here I’ll discuss what I see from some of this literature. Much of the research literature is only fully available if you have access to a university library (like me), but I’ll try to provide some links to at least the summary or abstract of the studies. Much of this literature is highly technical however, so don’t worry if it’s not so easy to digest.