学龄前儿童住宅室内多重途径的邻苯二甲酸酯环境暴露特征研究

Phthalates are a class of commonly used plasticizers. Epidemiological evidences have shown that phthalates, a group of endocrine disruptors, have detrimental effects on human reproductive and developmental function. Therefore, relevant human exposure measurement and risk assessment are of particular importance for public health. Children’s exposure to phthalates is still not well understood in China due to lack of relevant studies that are specifically designed for the very vulnerable population. Given such, we design the proposed study that aims at characterizing pre-school children’s multimedia environmental exposure to phthalates in residential indoor space. We propose to collect gas, airborne PM2.5 and dust samples in 60 dwellings as well as morning spot-urine samples of the pre-school children (4-7 years old) who live in these dwellings. The concentrations of phthalates and their urinary metabolites will be analyzed. The internal exposure doses and external exposure doses via multiple pathways will be estimated using the concentration data and relevant mathematical exposure models. The pre-school children’s exposure to phthalates in residential indoor space and the associated health risks will subsequently be characterized. In addition, we propose to examine the influences of exposure pathway absorption efficiency, gas-PM2.5-dust partition mechanisms, built environment and human behavior on pre-school children’s phthalates exposure. The research results will provide insightful information on health risks associated with children’s phthalates exposure in China, and will also provide scientific support for prospective development of exposure reduction strategy.

邻苯二甲酸酯(PAEs)是日常生活中广泛使用的增塑剂。PAEs具有内分泌干扰毒性并且流行病学研究已证实PAEs可影响人体正常的生殖和发育，因而相关的暴露评估和健康风险评价工作十分重要。由于我国缺乏专门针对儿童的PAEs暴露研究，因此对这一易感人群的PAEs暴露特征的认识十分有限。本课题专为研究4-7岁学龄前儿童的PAEs室内环境暴露特征而设计。本研究拟分析采自60户住宅室内的气相、PM2.5、降尘和儿童晨尿中PAEs或其代谢物的浓度；使用一室代谢模型和多重途径外暴露数学模型同步评估受试儿童的PAEs内外暴露水平；通过内外暴露相结合解析PAEs的环境暴露特征及累积健康风险，并分析各暴露途径的吸收效率、气相-PM2.5-降尘间PAEs的分配行为、建筑环境因素和人群行为因素对PAEs环境暴露特征的影响。研究成果有助于理解我国儿童的PAEs暴露风险，为制定相应的暴露控制措施提供科学依据。

邻苯二甲酸酯(PAEs)是日常生活中广泛使用的且具有内分泌干扰毒性的增塑剂。由于我国缺乏专门针对学龄前儿童的PAEs暴露研究，因此对这一易感人群的PAEs暴露特征的认识十分有限。本课题首先选取有4-7岁学龄前儿童居住的40户非近期装修住宅，分析室内的气相、PM2.5、降尘中7种PAEs浓度。研究发现空气中的主要phthalates (及其浓度) 为DMP（夏季和冬季，2442.3和2403.4 ng/m3，下同），DiBP（801.0和640.0 ng/m3）和DnBP（5173.2和1379.6 ng/m3）；PM2.5中的主要phthalates是DiBP（1055.1和585.9 ng/m3）和DnBP（1658.5和1517.0 ng/m3）和DEHP（215.1和344.9 ng/m3）；而降尘中主要为DiBP（44.6 ng/m3）、DnBP（76.6 ng/m3）和DEHP（515.1 ng/m3）。第二，本课题利用现场实测数据，首次获得真实室内环境条件下主要phthalates在气相-PM2.5-降尘的分配系数。以气相-PM2.5的分配系数（Kp）为例，夏季和冬季的中位值Kp（m3 /μg）分别为：0.053和0.011(DiBP)，0.010和0.004 (DnBP)，0.021和0.025(DEHP)。通过与理论的平衡值对比发现DnBP和DiBP的分配可能达到平衡而DEHP的分配远未达到平衡；结合建筑环境因素与phthalates浓度的关联性分析结果发现夏季高湿和强烈光化学反应导致的更高含量大气极性有机气溶胶使得该季节DnBP和DiBP的Kp值显著高于冬季。第三，本课题采用多元回归模型和非参数检验筛选出对室内空气和降尘中phthalates浓度有显著影响的建筑环境因素和人群行为因素。第四，本课题首次使用同步实测的环境phthalates浓度数据和儿童晨尿中phthalates代谢物浓度数据进行暴露评估；通过呼吸途径摄入的PAEs年日均暴露量排序为DEHP(764.1 ng/d-kg BW)、DnBP(538.9 ng/d-kg BW)、DMP(313.9 ng/d-kg BW)、DiBP(151.5 ng/d-kg BW)和DEP(17.5 ng/d-kg BW), BBzP和DOP暴露量不显著；夏季通过降尘摄入的DEHP、DiBP和DnBP暴露