title: Monitoring indoor exposure to organophosphate flame retardants: hand wipes and house dust.
abstract: BACKGROUND
  Organophosphate flame retardants (PFRs) are becoming popular replacements for the phased-out polybrominated diphenyl ether (PBDE) mixtures, and they are now commonly detected in indoor environments. However, little is known about human exposure to PFRs because they cannot be easily measured in blood or serum.
  
  
  OBJECTIVE
  To investigate relationships between the home environment and internal exposure, we assessed associations between two PFRs, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP), in paired hand wipe and dust samples and concentrations of their metabolites in urine samples (n = 53). We also assessed short-term variation in urinary metabolite concentrations (n = 11 participants; n = 49 samples).
  
  
  METHODS
  Adult volunteers in North Carolina, USA, completed questionnaires and provided urine, hand wipe, and household dust samples. PFRs and PBDEs were measured in hand wipes and dust, and bis(1,3-dichloropropyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), metabolites of TDCIPP and TPHP, were measured in urine.
  
  
  RESULTS
  TDCIPP and TPHP were detected frequently in hand wipes and dust (> 86.8%), with geometric mean concentrations exceeding those of PBDEs. Unlike PBDEs, dust TDCIPP and TPHP levels were not associated with hand wipes. However, hand wipe levels were associated with urinary metabolites. Participants with the highest hand wipe TPHP mass, for instance, had DPHP levels 2.42 times those of participants with the lowest levels (95% CI: 1.23, 4.77). Women had higher levels of DPHP, but not BDCIPP. BDCIPP and DPHP concentrations were moderately to strongly reliable over 5 consecutive days (intraclass correlation coefficients of 0.81 and 0.51, respectively).
  
  
  CONCLUSIONS
  PFR exposures are widespread, and hand-to-mouth contact or dermal absorption may be important pathways of exposure.
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Hoffman
authors.forename: Stavros
authors.initials: S
authors.lastname: Garantziotis
authors.forename: Linda S
authors.initials: LS
authors.lastname: Birnbaum
authors.forename: Heather M
authors.initials: HM
authors.lastname: Stapleton
mesh_terms: D000328:Adult; D000368:Aged; D016902:Air Pollution, Indoor / Q000032:analysis*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005411:Flame Retardants / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D010755:Organophosphates / Q000032:analysis / Q000378:metabolism / Q000652:urine; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D011075:Polybrominated Biphenyls / Q000032:analysis
chemical_list: D004391:Dust; D005411:Flame Retardants; D010755:Organophosphates; D009943:Organophosphorus Compounds; D011075:Polybrominated Biphenyls; C016805:tris(1,3-dichloro-2-propyl)phosphate; C005445:triphenyl phosphate