痕量元素在中国北方主要海产贝类和黄渤海表层沉积物中的含量及其环境指示意义

	痕量元素在中国北方主要海产贝类和黄渤海表层沉积物中的含量及其环境指示意义
	李培苗
学位类型	博士
导师	高学鲁
	2015-06-11
学位授予单位	中国科学院大学
学位授予地点	北京
关键词	痕量元素双壳贝类表层沉积物环境风险评价黄海渤海
摘要	海岸带可以被视为一个陆地和水生生态系统之间相互作用的地理空间，是世界上陆海相互作用最活跃的地区之一，对大量动植物和水生生物的生存至关重要，而海洋沉积物则是痕量元素的重要汇区。近年来，作为人为活动相关的过程产生的大量的痕量元素污染物通过未经处理的工业废水、市政污水、地表径流等各种方式进入沿海环境。痕量元素对生态环境有潜在毒性和威胁，因此，痕量元素污染引起了人们的广泛关注。为了获得一个直观的空间或种间分布，研究了痕量元素在中国北方主要海产贝类和黄渤海表层沉积物中的含量，主要研究内容如下： 1）对从中国北部沿海6个城市（大连、青岛，日照，潍坊，威海，烟台）8个当地海鲜市场中随机抽取的9种可食用双壳贝类（海湾扇贝、栉孔扇贝、牡蛎、沙蛤、文蛤、贻贝、菲律宾蛤仔、毛蚶和缢蛏）的159个样本进行了痕量元素污染的调查及风险评估。用电感耦合等离子体质谱仪（ICP-MS）和氢化物发生-原子荧光光谱仪（HG-AFS）对贝类可食用组织痕量元素浓度进行分析，然后采用多种评价标准对污染状况进行评估。使用美国环保局（USEPA）和世界卫生组织食品委员会食品添加剂专家委员会（WHO/JECFA）制定的每周允许摄入量（PTWI）、每日允许摄入量（ADI）和参考剂量（RfD）对中国北方居民人体健康风险进行评估，为消费者与海鲜消费相关的污染问题提供更好的认知。 2) 对来自渤海和黄海的表层沉积物进行了酸可挥发硫化物（Acid Volatile Sulfur；AVS）和同步浸取的金属（Simultaneously Extracted Metal；SEM）的测定，以评估沉积物质量。采用由美国环保局（USEPA）建立的[SEM]-[AVS]和([SEM]-[AVS])/f_OC方法进行微量金属生物毒性的评估。 3）采集了渤海湾海岸带的表层沉积物，对6种痕量金属（Cd、Cr、Cu、Ni、Pb和Zn）做出地球化学和环境评价。采用两种沉积物质量标准和两种地球化学标准化方法（地质累积指数和富集因子）来分析金属潜在风险和富集程度。痕量元素在中国北方主要海产贝类和黄渤海表层沉积物中的研究结果表明: 1）所采集的贝类中As、Cr、Hg和Pb 具有相似水平，而不同贝类中Cd、Cu和Zn浓度表现出明显差异。栉孔扇贝中Cd、牡蛎中Cu浓度水平明显比其他贝类高。必需痕量元素的含量比非必需痕量元素的含量高，Zn的含量最高。Cd和Pb之间、Cd和Zn之间、Cu和Zn之间存在显著的相关性。风险评价表明通过市售贝类消费引起的Cd和Cu人体健康风险暴露应给予绝对必要的关注。通过消费市售双壳贝类引起的其他微量元素（As、Cr、Hg、Pb和Zn）的人类健康风险暴露可以忽略不计。然而考虑到大多数沿海居民通常食用大量双壳贝类，必须予以关注。 2）贝类可食用组织中8种潜在有害元素（Ag、Be、Co、Ni、Sb、Se、Tl和V）含量的平均值从大到小依次是Se > Ni > V > Co > Ag > Sb > Be > Tl。获得的平均浓度分别为：Ag 133.57±211.05 ng/g，Be 11.54±4.74 ng/g，Co 0.16±0.10 μg/g，Ni 0.65±0.60 μg/g，Sb 13.92±10.66 ng/g，Se 0.80±0.29 μg/g，Tl 1.85±0.55 ng /g和V 0.33±0.12 μg/g。平均而言，不同采样城市及不同双壳贝类物种之间，Se具有最高的组织浓度，其次是Ni、V、Co、Ag、Sb和Be，而Tl含量最低。一般来讲，在这8个可量化的PHEs的研究中，Ag、Be、Co、Ni、Sb、Se、V和Tl没有明显的空间差异，考虑到Ni可能是贝类消费的一个风险因素，而且大多数沿海居民通常食用大量双壳贝类，必须引起关注。 3）莱州湾和獐子岛海域表层沉积物的[AVS]和[SEM]变化范围分别为0.71-11.03 和0.10-0.74 μmol/g干重。莱州湾[AVS]的浓度在河流出口的地区比较低，沿向海方向越来越高。[AVS]明显与TOC呈正相关。[SEM]明显与TOC、沉积物的含水量和细颗粒泥沙的含量呈正相关，与粗组分含量呈显著负相关。得到的结果表明，莱州湾和獐子岛海域表层沉积物质量较高，不会对生态系统造成负面影响。 4）AVS和SEM在北黄海（NYS）和渤海（BS）的空间分布特征不同。AVS在北黄海的含量分布范围为0.279 到5.131 μmol/g，在渤海的含量分布范围是0.570到 3.994 μmol/g；北黄海海域SEM的含量从0.086 到 1.264 μmol/g不等，渤海的SEM含量从0.538到1.462 μmol/g不等。AVS与沉积物中总有机碳呈明显正相关。SEM与总有机碳、沉积物中水含量和细粒级颗粒物含量呈显著的正相关，与粗粒级颗粒物含量呈显著地负相关性。[SEM]/[AVS]小于1的站点在北黄海有10个（共13个），在渤海有5个（共13个），表明北黄海的表层沉积物质量要高于渤海的。在北黄海，AVS与一些因素有明显的相关性，在渤海则不是，表明在渤海AVS含量分布受到更加复杂的人为影响。本研究中两种不同评价方法的结果有时会出现差异，因此用单一的方法来评价沉积物质量不够充分，用两种方法结合对比评价更加有效。 5）渤海湾潮间带表层沉积物中除Cr平均浓度比大陆上地壳部平均值（UCC）中浓度明显更高以外，其他元素的平均浓度与UCC中的浓度水平相当。所有研究的金属，它们在砂和粉砂质砂沉积物中的总浓度比粘土质粉砂沉积物中的低得多。平均而言，Cd、Cr、Cu、Ni、Pb和Zn在砂和粉砂质砂沉积物中的总浓度分别为0.08、43.6、9.7、15.3、19.9和39.5 μg/g ，粘土质粉砂沉积物中的相应的值分别是0.17、97.3、40.5、42.5、32.2和111 μg/g。对于除Cd外的每一种金属元素，他们的总浓度在粘土质粉砂沉积物中或在砂和粉砂质砂沉积物中的分布都非常相似，其变异系数一般小于10%。通过美国环保局（2004）标准进行评估表层沉积物质量，相关结果也与美国环保局（2005）沉积物质量指南进行比较。基于不同标准的沉积物质量评估结果比较表明有时候相互矛盾。所以，单一的评价方式对沉积物中重金属的生态风险评价是不足以得出准确的科学结论。本研究表明，基于不同种标准比较后的结果将更有效、更加有说服力。
其他摘要	While marine sediment is a major sink for trace elements, the coastal zone, one of the most active regions of land-ocean interaction in the world, can be considered as a geographic space of interaction between terrestrial and aquatic ecosystems that is crucial for survival of a large variety of plants, animals and aquatic organisms. In recent years, huge amounts of trace elements are entering the coastal environment as contaminants from anthropogenic-related processes by the ways of untreated industrial wastewater, municipal sewage effluent, surface run-off and so on. Trace elements have potential toxicity and threat to eco-systems, therefore, contamination of trace elements in the environment is of major concern. Trace elements in major marine bivalves from the northern China and in surface sediments of the Bohai Sea and the Yellow Sea were studied to obtain a visual representation of spatial or interspecific variations among the concentrations of these elements in samples. The major research was as follows: 1) 159 samples of nine edible bivalve species (Argopecten irradians, Chlamys farreri, Crassostrea gigas, Lasaea nipponica, Meretrix meretrix, Mytilus edulis, Ruditapes philippinarum, Scapharca subcrenata and Sinonovacula constricta) were randomly collected from eight local seafood markets in six cities (Dalian, Qingdao, Rizhao, Weifang, Weihai and Yantai) along the northern coastal areas of China for the investigation of trace element contaminations and risk assessment. The trace element concentrations in the edible tissues of collected bivalve species were analyzed by ICP-MS and HG-AFS, and then their pollution status were assessed using a variety of evaluation standards. The human risk assessment for people from the northern China was conducted using the provisional tolerance weekly intake (PTWI), acceptable daily intake (ADI), and reference dose (RfD) previously established by the United States Environmental Protection Agency (USEPA) and the Joint FAO/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) to provide consumers with better knowledge of contamination problems associated with seafood consumption. 2) The surface sediments from the Bohai Sea and the Yellow Sea were analyzed for acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) to assess the sediment quality. Two methods [SEM]-[AVS] and ([SEM]-[AVS])/f_OC established by the United States Environmental Protection Agency (USEPA) were adapted for assessment of trace metal biotoxicity. 3) Surface sediments from coastal zone of the Bohai Bay were sampled for the geochemical and environmental assessment of six trace metals (Cd, Cr, Cu, Ni, Pb and Zn). Two sediment quality guidelines and two geochemical normalization methods (index of geoaccumulation and enrichment factor) were used to judge the potential risk and accumulation of metals. Results of trace elements in major marine bivalves from the northern China and in surface sediments of the Bohai Sea and the Yellow Sea showed: 1) As, Cr, Hg, and Pb in all collected bivalve species had comparable levels while Cd, Cu, and Zn exhibited apparent differences in different bivalve species. Cd in Chlamys farreri and Cu in Crassostrea virginica exhibited apparent higher levels than other bivalve species. The concentrations of the essential trace elements were higher than those of the non-essential trace elements, with Zn concentrations being the highest. There were significant correlations between some elements (Cd-Pb, Cd-Zn, Cu-Zn). Risk assessments indicated that we should pay indispensable attention to human health risks associated with Cd and Cu exposure via consumption of marketed bivalves. Human health risks associated with the exposure to the other studied trace elements (As, Cr, Hg, Pb and Zn) via consumption of marketed bivalves were negligible. However, care must be taken considering that most coastal residents regularly consume large quantities of bivalves. 2) The average concentrations eight potential harmful elements (PHEs), namely Ag, Be, Co, Ni, Sb, Se, Tl and V, in the edible tissues of the sampled bivalves followed the order of Se > Ni > V > Co > Ag > Sb > Be > Tl. The recorded average concentrations of Ag, Be, Co, Ni, Sb, Se, Tl and V were 133.57±211.05 ng/g, 11.54±4.74 ng/g, 0.16±0.10 μg/g, 0.65±0.60 μg/g, 13.92±10.66 ng/g, 0.80±0.29 μg/g, 1.85±0.55 ng/g and 0.33±0.12 μg/g, respectively. On average, among different locations and bivalve species, Se had the highest tissue concentrations, followed by Ni, V, Co, Ag, Sb and Be, while the Tl levels were the lowest. Among the eight PHEs quantified in this study, Ag, Be, Co, Ni, Sb, Se, V and Tl had no clear spatial differences among all the locations generally. Care must be taken considering that Ni would be the risky factor and most coastal residents regularly consume large quantities of bivalves. 3) The concentrations of AVS ([AVS]) and SEM ([SEM]) of the surface sediments from Laizhou Bay (LB) and the coastal sea around Zhangzi Island (ZI) varied in the ranges 0.71-11.03 and 0.10-0.74 μmol/g dry weight, respectively. [AVS] was generally low in the river outlet area and increased in the seaward direction in LB. [AVS] was significantly and positively correlated with TOC. [SEM] was significantly and positively correlated with TOC, the water content of sediment and the fine sediment fraction and it was significantly and negatively correlated with coarse sediment fraction. The obtained results suggest that the surface sediments of LB and ZI were of high quality and not likely to cause negative effects on their ecosystems. 4) AVS and SEM exhibited different spatial patterns in surface sediments of NYS and BS. AVS was present in concentrations ranging from 0.279 to 5.131 μmol/g insurface sediments of NYS, while the corresponding concentrations of the surface sediments from BS were found varied within the range of 0.570 to 3.994 μmol/g.The SEM concentrations of the surface sediments from NYS ranged from 0.086 to 1.264 μmol/g, while the corresponding data in BS ranged from 0.538 to 1.462 μmol/g. [AVS] was significantly and positively correlated with the fine fraction, and negative correlation with coarse fraction and Eh in surface sediments of NYS and BS. [AVS] and [SEM] were significantly and positively correlated with TOC in surface sediments of NYS. [SEM]/[AVS] was smaller than one in 10 of the 13 surface sediments of NYS, while only 5 of the 13 surface sediments of BS had [SEM]/[AVS]<1, indicating that the surface sediments of NYS were of higher quality and less likely to cause negative effects on their ecosystems than those in BS. Significant correlations were observed between AVS and other parameters in the surface sediments of NYS but not in the surface sediments of BS indicating that this phenomenon was complex in the surface sediments of BS might due to common anthropogenic activities. A comparison of the results based on two different criteria by USEPA for sediment quality assessment shown that they were sometimes contradictory. Therefore, a single approach to quality assessment might be insufficient. It was preferable to do a comparison of the results based on different criteria for sediment quality assessment. 5) Except for Cr, the mean concentration of which is apparently higher than that in UCC, the mean concentrations of the other elements in surface sediments of intertidal Bohai Bay are comparable to their corresponding values in UCC. For all the metals studied, their total concentrations in sand and silty sand sediments are much lower than in clayey silt sediments. On average, their total concentrations in sand and silty sand sediments are 0.08, 43.6, 9.7, 15.3, 19.9 and 39.5 μg/g for Cd, Cr, Cu, Ni, Pb and Zn, respectively, and the corresponding values in clayey silt sediments are 0.17, 97.3, 40.5, 42.5, 32.2 and 111 μg/g, respectively. For each metal except Cd, its total concentrations in clayey silt sediments or in sand and silty sand sediments are very similar, and its coefficient of variation is usually <10%. Surface sediment quality was assessed according to USEPA (United States Environmental Protection Agency, 2004) standards, but the results were also compared with USEPA (United States Environmental Protection Agency) guidelines for sediment quality. A comparison of the results based on different criteria for sediment quality assessment shows that they are sometimes contradictory. Therefore, a single approach to quality assessment may be insufficient to get accurate scientific conclusions. The research suggest that a comparison of the results based on different criteria will be more convincing and effective.
语种	中文
文献类型	学位论文
条目标识符	http://ir.yic.ac.cn/handle/133337/8968
专题	中国科学院烟台海岸带研究所知识产出_学位论文
作者单位	中国科学院大学，中国科学院烟台海岸带研究所
推荐引用方式 GB/T 7714	李培苗. 痕量元素在中国北方主要海产贝类和黄渤海表层沉积物中的含量及其环境指示意义[D]. 北京. 中国科学院大学,2015.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
???????-R.pdf（2900KB）	学位论文	PDF	开放获取	ODC PDDL	浏览请求全文