Particle-size dust concentrations of polybrominated diphenyl ethers (PBDEs) in Southern Taiwanese houses and assessment of the PBDE daily intakes in toddlers and adults

Our goal was to determine PBDE levels in Taiwanese household dust and to examine the particle-size distribution of PBDEs in dust samples. Nine paired samples of floor and electronic dust were gathered from nine individual houses. Each sample was sieved with 100 (< 0.149 mm) and 200 (< 0.074 mm) meshes to obtain three fractionated samples (> 0.149, 0.074-0.149, and < 0.074 mm). Each house had 8 samples taken from it, including a pair of overall dust samples and 3 pairs of fractionated samples. Thirty PBDEs (BDE-7, 15, 17, 28, 47, 49, 66, 71, 77, 85, 99, 100, 119, 126, 138, 139, 140, 153, 154, 156, 183, 184, 191, 196, 197, 203, 206, 207, 208, and 209) in 72 dust samples were analyzed by high resolution gas chromatograph/ high resolution mass spectrometry (HRGC/HRMS). The levels of Σ₂₈PBDEs and PBDEs in electronic dust were not significantly higher than those in floor dust in the paired overall dust samples, or the three fractionated samples. In addition, the levels of Σ₂₈PBDEs and PBDEs were not significantly different for these three particle-sizes of floor and electronic dust. Based on the results of the factor analysis, the patterns of the PBDE distributions in floor and electronic dust were also very similar. A significant correlation of Σ₂₈PBDEs was shown in the paired samples of floor and electronic dust. For the three fractionated dust samples, we found that only the levels of PBDEs from di- to tetra- in floor dust were significantly correlated with those in electronic dust. This may be because the PBDE contaminants in floor and electronic dust might originate from the same exposure sources, particularly for lower brominated PBDE congeners. The toddlers (6-48 months) (median estimated PBDE daily intake from mean floor dust: 2.73 ng/kg b.w./day) possibly ingested more PBDEs in household dust compared to the adults (0.0414 ng/kg b.w./day) based on our results. Our sample size was too small to represent the level of PBDE contamination in house dust from southern Taiwan, and thus a larger scale study is encouraged. In conclusion, our findings suggest that it may be not necessary for household surveys of PBDEs to collect different meshes of dust.