Suzuki, G.; Tue, NM.; Takahashi, S.; Tanabe, S.; Sakai, S.; Malarvannan, G.; Sudaryanto, A.; Brouwer, A.; Uramaru, N.; Kitamura, S.; Takigami, H. (2012) Organohalogen Compounds, 74: A6. 107
Introduction
Indoor dust is a sink for many kinds of pollutants1. Exposure of children, especially infants and toddlers, to pollutants via indoor dust is suggested to be greater than exposure via other pathways1, although the relative exposures depend on individual lifestyle and habits. For example, the concentrations of polybrominated diphenylethers (PBDEs), which are flame retardants (FRs) in plastics, polyurethane foams, and textiles used for household items such as televisions (TVs), computers, and flameproof curtains, in house dust have recently been analyzed in various studies around the world, and the results suggest that house dust is an important route of exposure of children to PBDEs2. Recently, phosphate flame retardants (PFRs) also have been detected in indoor dusts3,4. Concentrations of PFRs such as triphenyl phosphate (TPhP) and tris(1,3-dichloroisopropyl) phosphate (TDCPP) in indoor dust tended to be higher than those of brominated FRs (BFRs) such as PBDEs. These results suggest that various plastic additives other than BFRs and PFRs are also transferred in indoor dust. Consequently, in order to select important contaminants in indoor dusts from a toxicological point of view for subsequent large-scale monitoring and testing of in vivo toxicity, there is a need for effective chemical assessment schemes such as toxicity identification evaluation and effect-directed analysis.
In this study, we used a panel of human cell-based CALUX reporter gene bioassays to evaluate steroid hormone-disrupting potency (human androgen receptor [AR], estrogen receptor α [ERα], progesterone receptor [PR], and glucocorticoid receptor [GR]-mediated activities), and lipid metabolism-disrupting potency (human peroxisome proliferator-activated receptor γ2 [PPARγ2] -mediated activity) as in vitro toxicity because previous studies clearly indicated BFRs such as PBDEs classified as POPs (POPs-PBDEs) to have nuclear hormone receptor-mediated activities5,6. As a first step for effective chemical assessment of indoor dust, in vitro toxicity characteristics were evaluated for indoor dust collected from various countries and for selected FRs. And then, in vitro toxicological similarities between dust and FRs were evaluated for further study such as identification of causative compounds.