Identifying Transfer Mechanisms and Sources of Decabromodiphenyl Ether (BDE 209) in Indoor Environments Using Environmental Forensic Microscopy

Abstract

Although the presence of polybrominated diphenyl ethers (PBDEs) in house dust has been linked to consumer products, the mechanism of transfer remains poorly understood. We conjecture that volatilized PBDEs will be associated with dust particles containing organic matter and will be homogeneously distributed in house dust. In contrast, PBDEs arising from weathering or abrasion of polymers should remain bound to particles of the original polymer matrix and will be heterogeneously distributed within the dust. We used scanning electron microscopy and other tools of environmental forensic microscopy to investigate PBDEs in dust, examining U.S.A. and U.K. dust samples with extremely high levels of BDE 209 (260-2600 µg/g), a non-volatile compound at room temperature. We found that the bromine in these samples was concentrated in widely scattered, highly contaminated particles. In the house dust samples from Boston (U.S.), bromine was associated with a polymer/organic matrix. These results suggest that the BDE 209 was transferred to dust via physical processes such as abrasion or weathering. In conjunction with more traditional tools of environmental chemistry, such as gas chromatography-mass spectrometry (GC/MS), environmental forensic microscopy provides novel insights into the origins of BDE 209 in dust and their mechanisms of transfer from products.

Estimating exposures to indoor contaminants using residential dust

“…PBDEs can be transferred from household items to indoor dust either as miniature fragments of foam or textiles via abrasion and weathering (Webster et al, 2009) or following vaporization of PBDEs from hot surfaces in electronics with subsequent adsorption on dust particles (Kose et al, 2008;Suzuki et al, 2009).…”

Indoor Contamination with Hexabromocyclododecanes, Polybrominated Diphenyl Ethers, and Perfluoroalkyl Compounds: An Important Exposure Pathway for People?

“…highly involatile congener, recent studies exploiting the utility of forensic microscopy suggest strongly physical weathering occurs of particles or fibers from flame-retarded items (64,65). These studies showed heterogeneous bromine distribution within dust containing very high BDE-209 concentrations, with samples dominated by a small number of particles/ fibers highly enriched in bromine.…”

BDE-209 in the Australian Environment: Desktop review

“…PBDEs are not physically bonded to polymers or textiles and may be released from their point source by off-gassing (volatilization), directly partitioning from their point source into other materials and via abrasion (8)(9)(10)(11). The widespread use of PBDEs in items commonly found in homes leads to contamination of the indoor environment, particularly of household dust (12,13).…”