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The CHARGE study: an assessment of parental occupational exposures and autism spectrum disorder
  1. Erin C McCanlies1,
  2. Claudia C Ma1,
  3. Ja Kook Gu1,
  4. Desta Fekedulegn1,
  5. Wayne T Sanderson2,
  6. Yunin J Ludeña-Rodriguez3,
  7. Irva Hertz-Picciotto3
  1. 1 Health Effects Laboratory, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
  2. 2 University of Kentucky Chandler Medical Center, Lexington, Kentucky, USA
  3. 3 Division of Environmental and Occupational Health, Public Health Sciences, University of California, Davis, California, USA
  1. Correspondence to Dr. Erin C McCanlies, Health Effects Laboratory, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA; eim4{at}


Objectives The aim of this study is to determine if parental occupational exposure to 16 agents is associated with autism spectrum disorder (ASD).

Methods Demographic, health and parental occupational data were collected as part of the CHildhood Autism Risks from Genetics and Environment study. The workplace exposure assessment was conducted by two experienced industrial hygienists for the parents of 537 children with ASD and 414 typically developing (TD) children. For each job, frequency and intensity of 16 agents were assessed and both binary and semi-quantitative cumulative exposure variables were derived. Logistic regression models were used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) to assess associations between parental occupational exposures 3 months pre-pregnancy until birth.

Results The OR of ASD in the children of mothers exposed to any solvents was 1.5 times higher than the mothers of TD children (95% CI=1.01–2.23). Cumulative exposure indicated that the OR associated with a moderate level of solvent exposure in mothers was 1.85 (95% CI=1.09, 3.15) for children with ASD compared with TD children. No other exposures were associated with ASD in mothers, fathers or the parents combined.

Conclusion Maternal occupational exposure to solvents may increase the risk for ASD. These results are consistent with a growing body of evidence indicating that environmental and occupational exposures may be associated with ASD. Future research should consider specific types of solvents, larger samples and/or different study designs to evaluate other exposures for potential associations with ASD.

  • autism spectrum disorder, paternal exposure, maternal exposure, occupational, solvents

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  • Contributors ECMcC was involved in study design, statistical analysis plan, interpretation of data and manuscript preparation. CCM was involved in cleaning and preparing the data for analysis, developing the ACCESS database for the workplace exposures and analysis plan. JKG contributed to the data analysis plan, conducted the statistical analysis and wrote the statistical analysis section of the manuscript. DF was involved in the design of the work and oversaw the statistical analysis. WTS conducted the workplace exposure assessment and contributed to manuscript preparation. YJL-R reviewed all the paper, electronic and voice records to determine how many fathers specifically responded to the work history questionnaire, and IH-P contributed ‘CHARGE data’ to the study design, statistical analysis plan and preparation of the manuscript.

  • Funding This study has been funded by National Institutes of Health: UL1-TR000002, UG3-OD023365. National Institute of Environmental Health Sciences: P01 ES11269, R01 ES015359, P30 ES023513. Eunice Kennedy Shriver National Institute for Child Health and Human Development: U54 HD079125. US Environmental Protection Agency through the Science to Achieve Results (STAR) program: R829388, R833292, RD83543201. National Occupational Research Agenda (NORA) funding.

  • Disclaimer The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.