Is house dust the missing exposure pathway for PBDEs? An analysis of the urban fate and human exposure to PBDEs.

Polybrominated diphenyl ether (PBDE) body burdens in North America are 20 times that of Europeans and some “high accumulation” individuals have burdens up to 1−2 orders of magnitude higher than median values, the reasons for which are not known. We estimated emissions and fate of ΣPBDEs (minus BDE-209) in a 470 km2 area of Toronto, Canada, using the Multi-media Urban Model (MUM-Fate). Using a combination of measured and modeled concentrations for indoor and outdoor air, soil, and dust plus measured concentrations in food, we estimated exposure to ΣPBDEs via soil, dust, and dietary ingestion and indoor and outdoor inhalation pathways. Fate calculations indicate that 57−85% of PBDE emissions to the outdoor environment originate from within Toronto and that the dominant removal process is advection by air to downwind locations. Inadvertent ingestion of house dust is the largest contributor to exposure of toddlers through to adults and is thus the main exposure pathway for all life stages other than the infan...