future science issues of bfrs
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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 - PowerPoint PPT PresentationTRANSCRIPT
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Future Science Issues of BFRs
Linda S. BirnbaumDirector, Experimental Toxicology Division
NHEERLResearch Triangle Park, NC
Region 2 Science Day/Non-Regulated Pollutants Workshop
NYC – October 25, 2005
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Why BFRs?
• 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
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TBBPA
• Extensive Ongoing Studies under “FIRE”
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HBCD
• Persistent; Bioaccumulative; Potentially Toxic
• Science Needs Exposure Information Toxicity Studies
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HBCD in 30 Canadian Human Milks (ppb lipid)
(Ryan and Patry, 2002)
Mean Median Min Max
6.6 1.3 0 126
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PBDEs
• Penta and Octa• No longer produced in US, but
continued use allowed• Persistence and bioaccumulation
-- continuing concern
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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
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BDE Structures
BDE 100
BDE 47
BDE 99
BDE 153
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Commercial Mixture vs. Humans
MediaBDE Congeners (%)
47 99 100 153 154Commercial PentaBDE 37 48 8 4 3
Human Tissue 54 14 8 20 4Hites 2004
WHY THE DIFFERENCE?• Environmental degradation/debromination?• Altered toxicokinetics?
Are most people like mice or rats?
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Deca
• High volume product• Worldwide presence• PPM concentrations in sediment• PPB concentrations in biota
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Deca Science Questions
• Deca Breakdown Photolytically Microbially Metabolically
• Is Deca (BDE209) itself toxic?• What about Deca Metabolites/
Breakdown Products?
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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