Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2018
Publication Date: N/A
Technical Abstract: Recent data have revealed that homes, offices and cars are often more polluted with environmental contaminants than the outdoors due to high use of textiles, electronics, and insulation that are treated with brominated flame retardants (BFRs). BFRs volatilize and/or weather from consumer products and become encumbered in household dust. Human ingestion or inhalation of household dust is a suspected exposure route for BFRs, particularly for infants whose hand-to-mouth activities would facilitate ingestion, and BFR dust levels have been correlated to human plasma levels. Almost all major classes of BFRs have been identified in household dust, including hexabromocyclododecane (HBCD), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and bis(2-ethylhexyl)-3,4,5,6-tetrabromophtalate (TBPH), at concentrations exceeding 1 µg/g. The goal of the present study was to determine the mammalian bioavailability of HBCD/TBB/TBPH at environmentally-relevant levels when bound to household dust or an oil vehicle in male rats. Standard reference material (SRM) 2585, a well-characterized household dust, was used as the source of HBCD/TBB/TBPH. An oil vehicle was prepared whose daily administration duplicated the natural HBCD/TBB/TBPH exposure from 390 mg of dust/day. Male Sprague-Dawley rats were randomly divided into a Control group (n = 3), an Oil-dosed group (n = 4), and a Dust-dosed group (n = 4). Feces and urine were collected daily throughout the study. Twenty four hours after their last exposure, the rats were euthanized and adipose tissue, brain, GI tract, kidney, liver, lung, muscle, blood, and skin were collected. Tissue and feces levels of HBCD isomers were determined by LC-MS, while the levels of TBB and TBPH were determined by GC-MS. HBCD isomers in household dust were bioavailable when ingested, although stereoisomerization or isomer bioavailability differences were evident. Analyses of the bioavailability and individual tissue levels of TBB and TBPH are on-going.