氟化工厂及周边区域全氟化合物的环境行为与人群暴露研究
文献类型：学位论文
| 作者 | 高燕 |
| 学位类别 | 博士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 江桂斌 ; 王亚韡 |
| 关键词 | PFASs, PFSA manufacturing facility, distribution and transport, bioaccumulation, human exposure 全氟化合物， 氟化工厂 ，环境分布生物 累积 ，人群暴露 |
| 其他题名 | Environmental behavior and human exposure to perfluoroalkyl acids around a manufacturing facility in China |
| 中文摘要 | 全氟化合物（Perfluoroalkyl substances，PFASs）具有环境持久性、远距离迁移能力、生物累积能力和潜在的生物毒性。 2009年全氟辛基磺酸及其盐类（Perfluorooctanesulfonate， PFOS）和全氟辛基磺酰氟（Perfluorooctane sulfonyl fluoride，PFOSF）被列入了斯德哥尔摩公约附件 B以限制其生产和使用；2015年全氟辛酸（Perfluorooctanoic acid，PFOA）被列入斯德哥尔摩公约的候选名单。本工作的研究内容主要围绕氟化工厂及其周边环境中全氟烷酸类化合物（Perfluoroalkyl acids，PFAAs）的分布规律研究，PFAAs及其异构体在母鸡体内的组织分布、排泄和子代传输规律研究，以及职业工人和周边居民对直链 /支链PFAAs的暴露途径及健康风险展开。论文共分为以下五个部分： 对氟化工厂及其周边区域的土芯样品、表层土壤样品、地下水和自来水样品中 PFAAs的空间分布和单体特征进行了研究。土芯样品中 PFAAs的浓度范围为1.19-1495 ng g-1 dw，其中 PFOS浓度在 3个主要单体中最高。整体上，土芯中PFAAs浓度由上到下呈下降趋势，其浓度与总有机碳（TOC）呈正相关。对表层土壤和地下水的研究发现，PFOS是表层土壤中最主要的PFAAs，而全氟丁酸（Perfluorobutanoic acid，PFBA）是地下水中最主要的 PFAAs。随着距工厂距离的增加，土壤和地下水样品中 PFAAs浓度显著降低。 2008-2012年期间，开展了氟化工厂职业工人体内 PFAAs的内暴露和代谢研究。通过对采集的血样和尿样进行分析，表明血清中 PFAAs浓度水平的时间变化趋势与化工厂的产品结构相关，工作部门、工作年限、性别等都是影响工人血清中 PFAAs水平的重要因素。我们采用两种方式通过一元模型计算 PFAAs的半减期。第一种是通过配对的血清和尿样计算 PFAAs的消除速率，进而计算半减期；另一种是通过每个工人不同时间血清样本的纵向数据计算。通过第一种方式计算的全氟己基磺酸盐（Perfluorohexanesulfonate，PFHxS）、PFOA和 PFOS半减期的平均值分别为 17.0、5.84和 52.0年；通过第二种方式计算的 PFHxS、PFOA和 PFOS半减期的平均值则分别为 3.79、1.68和 1.94年，是目前报道的半减期的最低值。如果考虑到工人 PFAAs的持续暴露，通过第二种方式计算的半减期仍然有可能高于三种 PFAAs的固有半减期。 进一步对工厂职业工人的直链/支链 PFAAs的人体负荷和可能的消除途径进行了研究。同时，收集灰尘、总悬浮颗粒物（ TSP）、饮水和食物以研究职业工人对 PFAAs异构体的外暴露途径。结果表明，血清中PFOS、PFOA和PFHxS的几何平均值分别为 1386、371和 863 ng mL-1。直链 PFOS、PFOA和 PFHxS是血清中主要的 PFAAs异构体，其百分比的平均值分别为 63.3%、91.1%和 92.7%，高于尿样中的直链异构体所占比例。工人对 PFAAs最重要的暴露途径是室内灰尘和 TSP。肾消除速率计算表明支链异构体比对应的直链异构体有更快的肾消除速率。分子对接模型结果表明，直链 PFOS（n-PFOS）比支链 PFOS与人血清白蛋白（HSA）有更强的结合能力。 在氟化工厂周边收集灰尘、食物、TSP和饮用水样品，并收集周边居民的血清样品，对周边居民可能的 PFAAs暴露途径和人体负荷进行了研究。该区域的灰尘和居民血清中的 PFAAs浓度均高于普通地区。饮食摄入是工厂周边居民最主要的 PFAAs摄入途径，而灰尘摄入也占重要地位。居民血清中的 PFAAs浓度与对应灰尘中 PFAAs的浓度呈正相关（p<0.05）。工人家属血清中的 PFAAs水平显著高于该区域普通居民（p<0.05）。通过调查，我们认为工人衣服携带的灰尘是工人家属直接暴露于相对高 PFAAs浓度的重要途径。对不同 PFAAs单体的研究发现，PFHxS和 PFOS具有更高的生物累积能力。 在氟化工厂周边的 3个采样点收集了母鸡及其对应的鸡蛋、水、土壤、食物和粪便，以研究 PFAAs及其异构体在母鸡中的富集特点、排泄和子代传输规律。结果表明散养鸡体内的 PFAAs水平高于养殖场母鸡，PFBA和PFOS是最主要的PFAAs，不同器官 PFAAs浓度平均值的范围为13.7-113 ng g-1 ww，蛋清中的浓度平均值为 5.34 ng g-1 ww，蛋黄中为 231 ng g-1 ww。n-PFOS在不同器官中的比例范围是 77.4%-98.1%。不同器官中 PFOS异构体的比例差别表明直链/支链异构体存在不同的富集行为。蛋清中 n-PFOS的比例为 86.5%，蛋黄中则为 87.2%，没有显著差别。粪便中 n-PFOS的比例为 72.9%，低于组织器官中的比例。结果表明，支链 PFOS比 n-PFOS更容易通过粪便排出，这可能是组织器官中n-PFOS比例相对较高的原因。 |
| 英文摘要 | Perfluoroalkyl substances (PFASs) have recently received much attention due to their persistence, wide distribution in the environment and potential toxicity. Perfluorooctanesulfonate and its salts (PFOS), perfluorooctane sulfonyl fluoride (PFOSF) have been listed in the Stockholm Convention as Persistent Organic Pollutants (POPs) in 2009 and PFOA has been listed as POPs candidate in 2015 on Persistent Organic Pollutants review committees 11 of Stockholm Convention. The objective of this work is to investigate the distribution and transport of perfluoroalkyl acids (PFAAs) and their isomers in the environment, bioaccumulation in chickens and health risk in exposed population around a perfluorosulfonates (PFSAs) manufacturing facility. The thesis includes five parts: Soil cores, surface soil, groundwater and tap water samples were collected around the PFSA manufacturing facility to investigate the concentrations and patterns of PFAAs in the environment. PFAAs concentrations were in the range of 1.19 to 1495 ng g-1 dry weight (dw) in soil cores. Thereinto, PFOS was the most abundant pollutant, followed by PFOA and PFHxS. PFAAs concentrations showed decreasing trends from upper layers to the bottom of the soil cores. The concentrations of PFAAs were positively correlated with total organic carbons (TOC) of the soil samples. PFOS was the predominant PFAAs in the surface soil samples while PFBA was the predominant PFAAs in the groundwater and tap water samples. Paired serum and urine samples were collected from workers in the manufacturing plant from 2008 to 2012 (n=302). High levels of PFHxS, PFOA and PFOS appeared in serum with median concentrations of 764, 427, and 1725 ng mL-1, respectively. Work assignment was recognized as the critical factor influencing the PFAA serum level, and temporal trends of PFAAs in workers were closely related to the production structure of the plant. The elimination of PFAAs was considered to be a first-order model, and the half-lives were calculated as Ln2/k, where k was defined as the elimination rate constant of PFAAs. We estimated the half-lives of PFAAs using two approaches. Firstly, k was estimated by the serum and urine PFAA levels,the menstrual blood volume, and the volume of distribution of PFAAs. Secondly, k was calculated by the longitudinal data of serum PFAAs in the same individual. The average estimated half-lives for PFHxS, PFOA, and PFOS were, respectively, 17.0 (95% confidence interval (CI), 13.0-20.9), 5.84 (95% CI, 4.27-7.42), and 52.0 (95%CI, 34.7-69.3) years by the first approach. These values could be considered the upper limits of the half-lives of PFAAs. In the second approach, the half-lives of PFHxS,PFOA, and PFOS were 3.79 (95% CI, 0.54–12.7), 1.68 (95% CI, 1.02–1.88), and 1.94(95% CI, 1.70–2.44) years, respectively, which were the shortest values among all the reported values. If considering the high levels of ongoing exposure to PFAAs in workers, the half-lives estimated in the second approach were even underestimated. Serum and urine samples were collected from 36 occupational workers in the manufacturing plant from 2008 to 2012 to evaluate the body burden and possible elimination of linear and branched PFAAs. Indoor dust, total suspended particles (TSP), diet and drinking water samples were also collected to trace ccupational exposure pathway to PFAA isomers. The geometric mean concentrations of PFOS, PFOA and PFHxS isomers in the serum were 1386, 371 and 863 ng mL-1, respectively.The linear isomer of PFOS, PFOA, and PFHxS was the most predominant PFAA in the serum, with mean proportions of 63.3%, 91.1%, and 92.7% respectively, which were higher than the proportions in urine. The most important exposure routes to PFAA isomers in the occupational workers were considered to be the intake of indoor dust and TSP. A renal clearance estimation indicated that branched PFAA isomers had a higher renal clearance rate than the corresponding linear isomers. Molecular docking modeling implied that linear PFOS (n-PFOS) had a stronger interaction with human serum albumin (HSA) than branched isomers did. Serum of local residents, dust, duplicate diet, and other environmental matrices were also collected around the manufacturing plant, and homologous series of PFAAs were analyzed. PFAA levels in dust and serum of local residents in this area were considerably higher than those in non-polluted area. Although dietary intake was the major exposure pathway in the present study, dust ingestion played an important role in this case. Serum PFAAs in local residents were significantly correlated with dust PFAAs levels in their living or working icroenvironment. Serum PFAAs and dust PFAAs were significantly higher in family members of occupational workers (FM) than in ordinary residents (OR) (p<0.01). After a careful analysis of the PFAAs exposure pathway, a potential pathway in addition to direct dust ingestion was suggested: PFAAs might transfer from occupational worker’s clothes to dinners via cooking processes. The bioaccumulative potential of PFHxS and PFOS were higher than other PFAAs, which suggested a substantial difference between the bioaccumulative ability of perfluorinated sulfonic acids and perfluorinated carboxylic acids. Tissues and organs of chickens, feces, eggs, water, soil and food samples around the manufactory were collected to study the isomer-specific accumulation, elimination and maternal transfer to eggs of PFAAs. PFBA and PFOS were the predominant PFAAs. The mean ∑PFAAs concentrations of different tissues and organs ranged from 13.7 to 113 ng g-1 wet weight (ww) in different tissues and organs. ∑PFAAs concentrations were 5.34 ng g-1 ww in the albumen and 231 ng g-1 ww in the yolk. n-PFOS was the predominant PFOS isomer followed by iso-PFOS. The n-PFOS proportions in tissues and organs ranged from 77.4% to 98.1%. The different PFOS isomer profiles illustrated that the linear and branched PFOS showed different accumulation behaviors. The mean n-PFOS proportion in the albumen was 86.5% while the proportion was 87.2% in the yolk. The mean n-PFOS proportion in the feces was 72.9%, which was lower than the proportions in all the tissues and organs. The result indicated that the branched PFOS isomers showed faster excretion rate than n-PFOS for chickens, in corresponding to the enrichment of n-PFOS in tissues and organs. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/36794]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 高燕. 氟化工厂及周边区域全氟化合物的环境行为与人群暴露研究[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
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