摘要
水域沉积物被认为是水环境中多氯联苯(polychlorinated biphenyls,PCBs)主要归宿之一,为了评估珠江三角洲水域环境中PCBs的污染水平及其生态环境影响,于2011年8月至2012年5月,采集并分析珠江八大入海口表层沉积物中PCBs的残留状况。通过对PCBs残留进行调查研究,分析探讨PCBs组成与分布特征、污染风险评价,以期为PCBs给珠三角沿岸海域环境带来的潜在危害评估提供基础资料。采用气相色谱-电子捕获(GC-ECD)法进行检测分析,结果表明:①珠江八大入海口表层沉积物中7种指示性多氯联苯同系物PCB28、PCB52、PCB101、PCB118、PCB153、PCB138和PCB180均有检出,其中PCB52检出率最高,达到100%,质量分数也最大,PCB138和PCB153次之,检出率均为75%,总体表现为低氯取代物质量分数高于高氯取代物,四氯取代物含量占沉积物PCBs总量比例最大;②7种指示性PCBs质量分数总和范围为6.58-47.46μg·kg-1,平均值为24.82μg·kg-1。PCBs含量变化在不同季节有明显差别,最高值出现在2月,最低值出现在8月。空间分布表现为西四口门沉积物中PCBs质量分数高于东四口门(虎门除外);③采用潜在生态危害指数法和加拿大沉积物环境质量标准SQG(sediment quality guideline)方法对珠江入海口多氯联苯污染状况进行初步评价,与国内外水域沉积物相比,珠江入海口表层沉积物中PCBs污染处于较高水平,存在生态污染风险,可能会引起生态负效应,其中磨刀门、崖门、虎门污染较为严重,应加强污染监管。
Sediments are considered to be one of the main destinations of polychlorinated biphenyls （PCBs） in the aquatic environ-ment. Therefore, in order to assess the pollution level of PCBs in the aquatic environment of the Pearl River Delta and their impact on the ecological environment, we collected and analyzed residual PCBs in surface sediments from the eight outlets of the Pearl Riv-er Delta from August, 2011 to May, 2012. Through survey of PCB residues, analysis of PCB composition and distribution character-istics, and pollution risk assessment, we aimed to provide basic information for assessment of the potential environmental hazards caused by PCBs in this area. The concentration of seven PCB residues was determined using a gas chromatography-electron capture detector. Seven polychlorinated biphenyl congeners （including PCB28, PCB52, PCB101, PCB118, PCB153, PCB138, and PCB180） were detected in the surface sediments, among which, the detection rate and mass concentrations of PCB52 were highest. The detec-tion rate of PCB52 was 100%, followed by PCB138 and PCB153, with detection rates of 75%. The mass concentrations of low chlo-rine PCBs were higher than those of high chlorine PCBs. The tetrachlorobiphenyl content accounted for the largest proportion of the total amount of sediment PCBs. Further, the total concentration of the seven PCBs ranged from 6.58 to 47.46 μg·kg-1, with an aver-age value of 24.82 μg·kg-1. The PCB content also varied significantly with the seasons. The highest value was observed in February and the lowest in August. In addition, the mass concentrations of PCBs in the west four outlets were higher than those in the east four outlets （except for the Humen Outlet）. Furthermore, the Hakanson ecological risk index method and Canadian sediment quality guidelines （SQG） were used to conduct a preliminary assessment of the pollution of PCBs. These assessments revealed that surface sediments from the Pearl River Estuary were at a greater risk of PCB contamination compared with sediments from other aquatic areas in China and abroad. This may indicate a certain level of potential ecological risk as well as a negative effect on the ecosystem, thus we should pay greater attention to the environment of the Modaomen, Yamen, and Humen Outlets, where greater amounts of pollution were observed.
出处
《生态环境学报》
CSCD
北大核心
2013年第1期135-140,共6页
Ecology and Environmental Sciences
基金
广东省海洋渔业科技推广专项(A2011009)
关键词
珠江入海口
多氯联苯
表层沉积物
风险评价
Pearl River estuary
PCBs
surface sediments
residual
risk assessment
