Abstract
BACKGROUND. Organophosphate ester flame retardants (OPFRs) are persistent organic chemicals that are commercially applied to a wide variety of consumer products including electronics, building materials, foam-based furniture and children’s clothing that have individually been shown to adversely impact neurodevelopmental outcomes including hyperactivity symptoms, working memory, IQ and depressive symptoms. METHODS. We quantified nine prenatal OPFR urinary metabolites [DPHP, DNBP+DIBP, BDCIPP, BCEP, BBOEP, BCIPP, BMPP, BEHP and DPRP] by HPLC-MS/MS in samples from participants in the MADRES cohort--an ongoing pregnancy cohort in urban Los Angeles. Detection frequencies ranged from 99.8% for DPHP to 24.2% for DPRP. Specific-gravity adjusted OPFR metabolites detected in 60% or greater samples [DPHP, DNBP+DIBP, BDCIPP, BCEP, and BBOEP] were modeled continuously and log transformed, and values ≤ LOD were imputed as LOD/√2. The remaining four metabolites were modeled as detect/non-detect [BCIPP, BMPP, BEHP, and DPRP]. We assessed prenatal OPFR exposure associations with neurodevelopmental outcomes from the Child Behavior Checklist 1.5/5 in 151 predominantly Hispanic/Latino (~78%) children at age 3 years. RESULTS. We found significant associations between several OPFR metabolite concentrations and neurobehavioral outcomes in single metabolite adjusted models [e.g., a 10% increase in DNBP+DIBP concentration was associated with a 3.3% (95% CI 0.02%-6.49%) increase in internalizing symptoms score and a 4.8% (0.82%-8.95%) increase in DSM pervasive symptoms score]. However, exposure to a particular compound does not occur in isolation; thus it is critical that multiple exposures be considered jointly in human studies. We will discuss various analytical approaches to quantify the effects of environmental mixtures and apply them to understand multiple OPFR chemical exposure effects on early childhood neurobehavioral outcomes in a highly exposed, socioeconomically disadvantaged population. CONCLUSIONS. The application of mixtures methods will yield important insight into the conditional associations of co-exposures and enhance health risk assessment for child neurodevelopmental outcomes. KEYWORDS. Neurodevelopment, children, chemical mixtures
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.