Autism and the Environment 101: Online Course 13
Possible Contributing Factors to Autism
Although questions have been raised about many chemicals for a long time, research dollars have only recently started to support the systematic evaluation of these toxins as possible risk factors for ASD. Before this funding was available for larger studies, scientists could only afford small studies. Many such smaller studies point to risk, but few or none prove that any one chemical is a “cause” of autism. Two reasons are that most studies have been narrowly focused and have small sample sizes.
There is another more fundamental reason that no “single cause” of autism has emerged from environmental studies or from genetic research. This is that many potential contributors to autism can have similar effects:
- Many different kinds of chemicals can impact similar vulnerable parts of our systems.
- Many different genes can target the same or related pathways.
Because of this, it is hard to tease out one strong cause. Because many seemingly environmental and genetic risks converge, no single cause of autism may ever jump out at us from the data. Because of this, we need to take seriously the potential harm that can be caused by various combinations of factors, even if no one of them is totally responsible by itself.