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Future Science Issues of BFRs. Linda S. Birnbaum Director, Experimental Toxicology Division NHEERL Research Triangle Park, NC Region 2 Science Day/Non-Regulated Pollutants Workshop NYC – October 25, 2005. Flame retardants save lives Many classes of FRs BFRs most cost effective
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Future Science Issues of BFRs Linda S. Birnbaum Director, Experimental Toxicology Division NHEERL Research Triangle Park, NC Region 2 Science Day/Non-Regulated Pollutants Workshop NYC – October 25, 2005
Flame retardants save lives Many classes of FRs BFRs most cost effective >75 different BFRs Br-BPs, BDEs, CDs, phenols, phthalates,++ Global, transboundary problem Persistence Potential for bioaccumulation Limited data base Why BFRs?
TBBPA • Extensive Ongoing Studies under “FIRE”
HBCD • Persistent; Bioaccumulative; Potentially Toxic • Science Needs • Exposure Information • Toxicity Studies
HBCD in 30 Canadian Human Milks (ppb lipid)(Ryan and Patry, 2002)
PBDEs • Penta and Octa • No longer produced in US, but continued use allowed • Persistence and bioaccumulation -- continuing concern
Penta and Octa Science Questions • How are the congeners getting into the environment? • Environmental fate and transport? • Pathways of human exposure • Dust>Diet??? • Modes of action for toxic effects
BDE Structures BDE 47 BDE 153 BDE 99 BDE 100
Commercial Mixture vs. Humans Hites 2004 WHY THE DIFFERENCE? • Environmental degradation/debromination? • Altered toxicokinetics? • Are most people like mice or rats?
Deca • High volume product • Worldwide presence • PPM concentrations in sediment • PPB concentrations in biota
Deca Science Questions • Deca Breakdown • Photolytically • Microbially • Metabolically • Is Deca (BDE209) itself toxic? • What about Deca Metabolites/ Breakdown Products?
Potential Health Risk of PBDEs • Margin of exposure for PBDEs appears low • Additional concerns: • Are PBDEs interacting with other PBTs? • Contamination with Brominated Dioxins/Furans