Grant: Banting Postdoctoral Fellowship Program

The potential for environmental contaminants to produce neurobehavioral deficit as a result of in utero exposure has received increasing attention. Emergent pollutants such as polybrominated diphenyl ethers (PBDE), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) are of concerns for their potential risks to human health. They are used as brominated flame-retardant (BFR) additives in the manufacture of household items (eg TV sets, toys...). Recently, data showed that PBDE levels in breast milk of North American women are doubling every 5 years. In addition, PBDE levels in pregnant women's plasma are 20 to 106 fold higher than those of Swedish women. HBCDs and TBBA levels have never been monitored in Canadian women. Foetal brain is more susceptible to toxic exposure due to blood-brain barrier immaturity. In rodents, low doses exposure to BFR during development leads to hyperactivity and neurobehavioral impairments. In addition, foetus is usually exposed to a mixture of pollutants. When mixed, even at low doses, these substances can have additive adverse effects. Animal studies showed that PBDE, polychlorinated biphenyls (PCB) and mercury, all present in cord blood, can interact to enhance neurobehavioral defects. In spite of these observations, there are still no data on combined effect of BFR and other pollutants on neurodevelopment. I propose to conduct a follow up study which is the first who addresses exposure to PBDE, TBPPA and HBCDs in relation to psychomotor skills and behaviour in childhood. Pre- and post-natal BFR exposure as well as interaction between BFR and known neurotoxic pollutants will be studied. This study is a part of an ongoing study including 800 pregnant women and their babies. We now are processing with the 2-year old follow up. A complete biobank and a database are available to test my hypothesis. The biobank will be used to analyse BFR levels which will be correlated to neurobehaviour skills at 2 and 4 years old.