目前学术界比较关注的有机阻燃剂包括多溴二苯醚（polybrominated diphenyl ethers，PBDEs）、新溴代阻燃剂（novel brominated flame retardants，NBFRs）、磷代阻燃剂（phosphorus flame retardants，PFRs）以及德克隆（Dechlorane Plus，DPs）等，广泛应用在塑料、纺织品和电缆等材料中。 在空间变化研究方面，采集了办公室、宾馆、幼儿园、宿舍等四类室内灰尘样品和道路灰尘样品。对粒径<50 洀萀灶尘样品的分析结果表明，五类灰尘样品都存在比较严重的有机阻燃剂污染现象，但彼此之间的有机阻燃剂结构和污染水平表现出一定差异。PFRs（124,000 ng g-1）、NBFRs（14,200 ng g-1）、PBDEs（23,700 ng g-1）和DPs（231 ng g-1）分别在宾馆、宿舍、道路和幼儿园灰尘中呈现出最高浓度，预示着在相应空间内工作、生活或学习的人群可能面临着较为严重的有机阻燃剂暴露风险。 在时间变化研究方面，选取三间位于北京海淀区的办公室作为研究对象，通过连续采样分析，报道了PBDEs、NBFRs和PFRs在办公室灰尘中的季节变化规律并结合文献报道对其影响因素做了分析。PBDEs和NBFRs的浓度在全年总体保持稳定，而PFRs在不同季节的浓度高低顺序为：春天>冬天>秋天>夏天，这可能与PFRs普遍具有较强的挥发性有关。通过模型分析了有机阻燃剂在室内灰尘中的年际变化规律。 在粒径分布研究方面，将幼儿园、宿舍、办公室、宾馆和道路灰尘细分为13个粒径段，结果发现不同粒径段中有机阻燃剂的浓度不同，普遍呈现出“三峰一谷”的分布特征，即在900、100、15 μm粒径段附近出现浓度峰值，而在40 μm粒径段前后出现浓度谷值。结合文献报道分析了影响有毒污染物在灰尘中粒径分布特征的影响机制。灰尘粒径及其人体可暴露性之间存在密切关系，粒径<100 μm的灰尘颗粒更易于被人体暴露，因此在进行灰尘中有机阻燃剂人体暴露评估的过程中需要更加关注细颗粒物。以本研究和文献数据为基础，计算发现不同粒径选择所得出的有毒污染物的分析结果可能相差数倍乃至10多倍，由此提出灰尘粒径是评价室内灰尘健康效应必须考虑的重要因素。基于以上研究，本文提出了新的灰尘中有毒污染物人体暴露评估方法。

Organic flame retardants are a class of widespread pollutants in indoor environment, and are currently the most concerned indoor pollutants. Organic flame retardants with high concern include polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), phosphorus flame retardants (PFRs) and Dechlorane Plus (DPs), which are widely applied in plastics, textiles, foams, paints and cables. Indoor dust is the most important indoor sink of organic flame retardants and dust ingestion is the most important human exposure pathway. However, researches on organic flame retardants in indoor dust in China are limited and the contamination characteritics are badly understood. Dust samples were collected in Beijing, China, from four different kinds of indoor microenvironments (office, hotel, kindergarten and dormitory) and from outdoors (road). In the fractions <50 洀, levels and patterns of organic flame retardants varied among different types of microenvironments, implying different flame retardant usages and human exposure characteristics. PFRs had the highest concentration in hotel dust (124,000 ng g-1). NBFRs had both the highest level and contribution in dormitory dust (14,200 ng g-1). The highest concentration of DPs were detected in kindergarten dust (231 ng g-1), but they accounted only for <5% of total organic flame retardants. Unexpectedly, BDE-209 was the dominant flame retardant in road dust (96% of total organic flame retardants); its concentration (23,700 ng g-1) was even higher than in any indoor dust. This study documents the temporal variability in concentrations of organic flame retardants in floor dust from three offices in Beijing, China. With intensive and continuous sampling, we report for the first time on clear and coherent temporal trends of PBDEs, NBFRs and PFRs in office dust. The observed mean concentrations of PBDEs, NBFRs and PFRs, were 554, 11,100 and 128,000 ng g-1 in dust of office A; 7,560, 5,000 and 17,300 ng g-1 in dust of office B; and 4,750, 3,550 and 17,200 ng g-1 in dust of office C, respectively. Two to ten-fold variations were observed between the minimum and maximum concentrations of organic flame retardants in the same office. Different seasonality was distinctively found between BFRs (brominated flame retardants, including PBDEs and NBFRs) and PFRs. BFR levels in office dust were generally constant among different seasons. The abundance rank order for PFRs was: spring > winter > autumn > summer. This pattern may be attributable to the fact that PFRs are more sensitive to temperature changes compared to PBDEs and NBFRs owning to their higher volatilities. These five composite samples (office, hotel, kindergarten, dormitory and road dust) were fractionated into 13 sequential size fractions for further analysis. Peak values of organic flame retardents were always found in fractions with particle size of 900, 100 and 15 μm, and valley values were always found in fractions with particle size of 40 μm. For distribution patterns of organic flame retardants with particle size, large differences were found between indoor dust and road dust, and organic flame retardants were dominantly enriched in fractions <50 μm in road dust. Calculation results based on results of this study and literature data shows that with different selections of dust fractions, analytical results of toxic chemicals would vary up to 10-fold, which means that selecting dust fractions arbitrarily will lead to large errors in assessment of human exposure to toxic chemicals in settled dust. For researches on toxic chemicals in settled indoor dust, selection of dust fraction is a critical influencing factor which should be of high concern. Taking into account the significance of dust particle size, a new methodology for assessment of human exposure to toxic chemicals in settled indoor dust is proposed.