【摘要】 对长江口泥质沉积区ZK6孔沉积物进行了粒度分析、同位素测年、8个重金属元素(As、Cd、Cr、Cu、Hg、Ni、Pb、Zn)含量对比分析,综合评价了1500年以来沉积物粒度和重金属元素垂向变化特征,并从长江流域环境变化的角度揭示了流域人类活动对长江口沉积物元素赋存的影响规律。研究结果显示,ZK6孔平均沉积速率为1.85cm/a;As、Cd自底部到顶部表现出元素含量一直在逐步升高的趋势;Cr元素自底部到顶部,表现出元素含量逐步降低的趋势;Cu、Hg、Pb、Ni、Zn元素,表现出自底部到顶部先逐步降低后又含量升高的趋势;除Cr外其他几个元素自2m以浅含量明显升高、变幅增大。8个重金属元素对长江流域环境变化的响应敏感程度由高到低依次为Cd>As>Hg>Cu>Pb>Zn>Ni>Cr。Cd、As、Hg是长江流域特别需要加强环境风险监控的指标,潜在的含量变化趋势应引起高度重视。更多还原

【Abstract】 The sediment samples of the core ZK6 taken from the coastal muddy deposits of the Yangtze Estuary are analyzed for grain-size,isotopic activities and contents of eight heavy metal elements of As,Cd,Cr,Cu,Hg,Ni,Pb,Zn by the authors.Comprehensive evaluation of the vertical variation in grain size and the heavy metal elements are carried out for the past 1500 years.Human activities and their influence on the element distribution patterns are revealed based on environment changes.The sedimentation rate of ZK6 core is 1.85 cm/a on average.Both As and Cd show an increasing trend from bottom to top,while Cr a trend of gradual decrease.The contents of Cu,Hg,Pb,Ni and Zn elements show a decrease trend in the beginning and turn to increase later on.In addition to Cr,several other elements significantly increase from 2m upwards.The response sensitivity of 8 heavy metal elements to environmental changes in the basin range in a descending order of Cd>As>Hg>Cu> Pb>Zn>Ni>Cr.Cd,As and Hg are the alarm of the urgent need in environmental risk monitoring.In such a circumstance,special attention is required.更多还原