According to an exploratory study by Erin McCanlies, a research epidemiologist from the National Institute for Occupational Safety and Health (NIOSH), and colleagues, exposure to these chemicals could play a part in causing autism. Their pilot study is published online in Springer’s Journal of Autism and Developmental Disorders.
The expert’s assessment indicated that exposures to lacquer, varnish and xylene (a solvent found in some ink, rubber, and paint thinner) occurred more often in the parents of children with Autism Spectrum Disorder (ASD) compared to the parents of unaffected children.
Parents of children with ASD were also more likely to report exposures to asphalt and solvents, compared to parents of unaffected children.
The NIOSH researchers evaluated whether parents’ exposure to chemicals at work might be associated with autism spectrum disorder in their children in a sample of 174 families — 93 of which included children with autism spectrum disorder and 81 with children experiencing typical development.
These findings bolster earlier research showing that prenatal chemical exposure could predispose kids to autism.
A 2006 study looking at air pollutants in the San Francisco Bay Area concluded that there was a potential association between autism and estimated metal concentrations, and possibly solvents, in ambient air around the birth residence but determined that these results required future studies to explore the link.
“Overall, these results add to the mounting evidence that individual exposures may be important in the development of ASD,” McCanlies says. “However, these results are preliminary and are not conclusive. Additional research is required to confirm and extend these initial findings.”
The researchers described the study as “a first pass screen from which results can be used to target future research directions.”
While consensus among mainstream autism researchers is that genetic factors predominate; environmental factors that have been claimed to contribute to autism or exacerbate its symptoms, include certain foods, infectious disease, heavy metals, solvents, diesel exhaust, PCBs, phthalates and phenols used in plastic products, pesticides, brominated flame retardants, alcohol, smoking and illicit drugs. Some of these factors have been largely disproved and others require further study – the causes of autism are still a mystery.
The NIOSH researchers concluded that further studies that employ larger sample sizes and investigate interactions between workplace exposures and genetic factors would be beneficial.