are Organophosphate flame Retardants Affecting the NeuroDevelopment ? A Neuroimaging Investigation – ORANDANI

Organophosphate flame retardants (OPFRs) are emerging chemicals with high prevalence and controllable sources of exposure. Toxicological studies support their neurotoxicity, but epidemiological studies on their effects on child mental health are scarce and challenged by the below-mentioned features. They often relied on single urine spot samples to assess exposure which, due to OPFRs short half-life, leads to measurement error and biased effect estimates. None has considered postnatal exposure, a critical period for brain development. These studies only relied on neuropsychological testing or behavioral rating scales which are critical to identify the impact on child mental health but provide limited information on the brain structures and neural functions affected.
We aim to provide the first investigation of the effects of OPFRs on brain morphology, structures and cognitive functioning. We will also investigate their effects on child neurodevelopment (cognition, behavior and social aspects) between 2 and 8 years.
We will rely on a recent mother-child cohort for which multiple urine samples have been collected. This allows to precisely assess exposure to OPFRs during pregnancy, infancy and childhood and strongly limit measurement error compared to former studies relying on spot samples. Mental health (cognition, behavior and social aspects) will be evaluated between 2 and 8 years by trained neuropsychologists, validated questionnaires and computer-based tests allowing objective assessments. At 8 years, children will participate to a brain magnetic resonance imaging (MRI) sub-study that will combine 1) structural MRI, 2) advanced diffusion weighted imaging (DWI) and 3) functional MRI. This will allow to improve the understanding of OPFRs effects on the brain and strengthen biological plausibly for the associations observed with child mental health. This project is likely to translate to relevant policies better protecting the health of our children.