Exposure to certain solvents in the workplace, such as lacquer, varnish and xylene, could be linked to a child’s autism.
An exploratory study by Erin McCanlies, a research epidemiologist from the National Institute for Occupational Safety and Health (NIOSH), found that such exposures could play a role, but note that more research is needed to confirm an association.
The expert’s assessment indicated that exposures to lacquer, varnish and xylene 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 origins of ASD, a group of developmental conditions including full syndrome autism, Asperger’s syndrome, and pervasive development disorder, are unclear.
Autism spectrum disorder is characterized by a number of brain abnormalities, which may be partly caused by genetic factors, but could also be the result of environmental or parental occupational exposures, according to earlier studies. These exposures have been associated with adverse pregnancy outcomes and other neurodevelopmental conditions in children.
The NIOSH researchers used data from the Childhood Autism Risk from Genetics and the Environment (CHARGE) study at the UC Davis MIND Institute in Sacramento, Calif. They carried out exploratory analyses to evaluate whether parents’ exposure to chemicals at work could be associated with ASD in their children, using a sample of 174 families, including 93 children with ASD and 81 with typical development.
Both parents took part in phone interviews to assess exposures during the three months prior to pregnancy, during the pregnancy, and up to birth or weaning if their child was breastfed. In addition, industrial hygienists independently assessed the parents’ exposure levels.
“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 and should therefore not be taken as conclusive.”
Further understanding will continue to come through studies that employ larger sample sizes and that investigate interactions between workplace exposures and genetic factors, the researchers conclude.
The pilot study was published online in Springer’s Journal of Autism and Developmental Disorders.