Does the source migration pathway of HBCDs to household dust influence their bio-accessibility?

Abstract

A study was conducted to assess the human bioaccessibility of dust contaminated with hexabromocyclododecane (HBCD) via two migration pathways a) volatilisation with subsequent partitioning to dust particles, and b) abrasion of treated textile fibres directly to the dust. This was achieved using previously developed experimental chamber designs to generate dust samples contaminated with HBCDs emitted from a HBCD treated textile curtain. The generated dust samples were exposed to an in vitro colon extended physiologically based extraction test (CE-PBET). The bioaccessibility of the HBCDs which were incorporated within dust as a result of volatilisation from the curtain material with subsequent partitioning to dust was higher than in dusts contaminated with HBCDs via abrasion of the curtain (35% and 15% respectively). We propose this occurs due to a stronger binding of HBCDs to treated fabric fibres than that experienced following volatilisation and sorption of HBCDs to dust particles.

Oral bioaccessibility of semi-volatile organic compounds (SVOCs) in settled dust: A review of measurement methods, data and influencing factors

“…The presence of SVOC in indoor dust can arise through three mechanisms: (i) via volatilization and re-condensation of the SVOC on dust particles (air mediated transfer), (ii) via direct transfer from horizontal surfaces to dust, and (iii) via weathering or abrasion of polymers [96][97][98]. In the first two cases, the SVOC is sorbed onto the surfaces of dust particles, whereas in the third case, the SVOC is a constituent of dust particles [73,96]. These migration pathways could lead to different bioaccessibilities, and sorbed SVOCs could be more bioaccessible than constitutive SVOCs.…”

“…Yu et al hypothesized that these different migration pathways could explain the lower PBDEs bioaccessibility in indoor dust than in outdoor dust since indoor dust is more likely to contain fragments of materials than outdoor dust [72]. In their next study, they compared the bioaccessibility of PBDE-spiked dust versus However, in a more recent study, an experimental chamber was used to compare the bioaccessibility of HBCDs in a pre-characterized dust that had been enriched by HBCDs originating from treated textile via the two migration pathway: HBCDs bioaccessibility in dust contaminated via volatilization (35%) was greater than in dust contaminated by abrasion (15%) [73]. This study confirms the general tendency of sorbed compounds being more bioaccessible than constitutive ones, although more studies need to be performed with other SVOCs sources.…”