Influence of Low-Level Prenatal Exposure to PCDD/Fs and PCBs on Empathizing, Systemizing and Autistic Traits: Results from the Duisburg Birth Cohort Study

PLoS One. 2015 Jun 12;10(6):e0129906. doi: 10.1371/journal.pone.0129906. eCollection 2015.

Abstract

Background: Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are assumed to act as endocrine disruptor chemicals. Prenatal exposure to these pollutants might influence fetal steroid hormone levels, which are thought to be related to sex-typical development and autistic traits.

Objectives: We examined associations of prenatal levels of PCDD/Fs and PCBs with autism traits and sex-typical behaviour in childhood.

Methods: We measured levels of PCDD/Fs and PCBs in maternal blood samples during pregnancy using gas chromatography/high-resolution mass spectrometry. Sex-typical behaviour was assessed at 9 years of age (n = 96) and autistic traits at 10 years of age using the Social Responsiveness Scale (SRS; n = 100). Multiple regression analyses were conducted to estimate the associations between prenatal exposure and outcome variables.

Results: Blood concentrations (WHO2005-TEq) of ƩPCDD/Fs ranged from 2.93-46.45 pg/g lipid base (median = 12.91 pg/g lipid base) and concentrations of ƩPCBs were in the range of 1.24-25.47 pg/g lipid base (median = 6.85 pg/g lipid base) which is within the range of German background exposure. We found significant negative associations between PCDD/F levels in maternal blood and SRS scores in the whole group (β = -6.66, p < .05), in girls (β = -10.98, p < .05) and, in one SRS subscale, in boys (β = -6.86, p < .05). For PCB levels, associations with one SRS subscale were significant for the whole study group as were associations with two subscales in girls. We did not find significant associations between PCDD/F or PCB levels and sex-typical behaviour for either sex.

Conclusions: In an earlier part of this study, prenatal exposure to PCDD/Fs and PCBs was found to be associated with lower testosterone levels, therefore, our findings are consistent with the idea that autism spectrum conditions are related to fetal androgen levels. Several possible mechanisms, through which PCDD/Fs and PCBs might influence autistic behaviour, are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autism Spectrum Disorder / epidemiology*
  • Benzofurans / adverse effects*
  • Benzofurans / blood
  • Child
  • Dibenzofurans, Polychlorinated
  • Environmental Pollutants / adverse effects*
  • Environmental Pollutants / blood
  • Female
  • Germany
  • Humans
  • Male
  • Polychlorinated Biphenyls / adverse effects*
  • Polychlorinated Biphenyls / blood
  • Polychlorinated Dibenzodioxins / adverse effects
  • Polychlorinated Dibenzodioxins / analogs & derivatives*
  • Polychlorinated Dibenzodioxins / blood
  • Pregnancy
  • Prenatal Exposure Delayed Effects*

Substances

  • Benzofurans
  • Dibenzofurans, Polychlorinated
  • Environmental Pollutants
  • Polychlorinated Dibenzodioxins
  • Polychlorinated Biphenyls

Grant support

The study was initiated and financially supported by the NorthRhine-Westphalia State Environment Agency (http://www.lanuv.nrw.de/englisch/home.htm). The follow-up was funded by the German Federal Environment Agency (3708 61 201 3; http://www.umweltbundesamt.de/en). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.