State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China.
Environ Res. 2018 Apr;162:166-172. doi: 10.1016/j.envres.2017.12.014. Epub 2018 Jan 6.
The effect of dust particle size on the distribution and bioaccessibility of flame retardants (FRs) in indoor dust remains unclear. In this study, we analyzed 20 FRs (including 6 organophosphate flame retardants (OPFRs), 8 polybrominated diphenyl ethers (PBDEs), 4 novel brominated flame retardants (NBFRs), and 2 dechlorane plus (DPs)) in composite dust samples from offices, public microenvironments (PME), and cars in Nanjing, China. Each composite sample (one per microenvironment) was separated into 6 size fractions (F1-F6: 200-2000µm, 150-200µm, 100-150µm, 63-100µm, 43-63µm, and <43µm). FRs concentrations were the highest in car dust, being 16 and 6 times higher than those in offices and PME. The distribution of FRs in different size fractions was Kow-dependent and affected by surface area (Log Kow=1-4), total organic carbon (Log Kow=4-9), and FR migration pathways into dust (Log Kow>9). Bioaccessibility of FRs was measured by the physiologically-based extraction test, with OPFR bioaccessibility being 1.8-82% while bioaccessible PBDEs, NBFRs, and DPs were under detection limits due to their high hydrophobicity. The OPFR bioaccessibility in 200-2000µm fraction was significantly higher than that of <43µm fraction, but with no difference among the other four fractions. Risk assessment was performed for the most abundant OPFR-tris(2-chloroethyl) phosphate. The average daily dose (ADD) values were the highest for the <43µm fraction for all three types of dust using total concentrations, but no consistent trend was found among the three types of dust if based on bioaccessible concentrations. Our results indicated that dust size impacted human exposure estimation of FRs due to their variability in distribution and bioaccessibility among different fractions. For future risk assessment, size selection for dust sampling should be standardized and bioaccessibility of FRs should not be overlooked.
尘埃颗粒大小对室内灰尘中阻燃剂（FRs）的分布和生物可利用性的影响尚不清楚。本研究分析了中国南京办公室、公共微环境（PME）和车内复合尘埃样品中的 20 种 FRs（包括 6 种有机磷阻燃剂（OPFRs）、8 种多溴二苯醚（PBDEs）、4 种新型溴化阻燃剂（NBFRs）和 2 种十氯酮（DPs））。每个复合样本（每个微环境一个）分为 6 个粒径分数（F1-F6：200-2000μm、150-200μm、100-150μm、63-100μm、43-63μm 和 <43μm）。FRs 浓度在车内尘埃中最高，是办公室和 PME 的 16 倍和 6 倍。FRs 在不同粒径分数中的分布与 Kow 有关，受表面积（Log Kow=1-4）、总有机碳（Log Kow=4-9）和 FR 进入尘埃的迁移途径（Log Kow>9）的影响。通过基于生理学的提取试验测量 FRs 的生物可利用性，OPFR 的生物可利用性为 1.8-82%，而由于其高疏水性，可生物利用的 PBDE、NBFR 和 DP 则低于检测限。200-2000μm 粒径分数中的 OPFR 生物可利用性明显高于<43μm 粒径分数，但其他四个粒径分数之间没有差异。使用总浓度对最丰富的 OPFR-三（2-氯乙基）磷酸进行风险评估。对于所有三种类型的尘埃，<43μm 粒径分数的平均日剂量（ADD）值最高，但如果基于生物可利用浓度，则三种类型的尘埃之间没有一致的趋势。我们的结果表明，由于 FRs 在不同粒径分数之间的分布和生物可利用性的差异，尘埃粒径会影响对 FRs 的人体暴露评估。对于未来的风险评估，应标准化尘埃采样的粒径选择，并且不应忽视 FRs 的生物可利用性。
