According to the monitoring results of the surface sediment samples from five cruises of 150 survey stations from 2006 to 2014 collected in the adjacent sea water of the Yellow River estuary,the pollution status and the annual variations of the seven kinds of heavy metals Hg,Cu,Pb,Cd,Cr,Zn and As in the sediments were analyzed.The methods of single factor standard index and potential ecological risk index were used to evaluate the status of heavy metal pollution and potential ecological risk degree.The results showed that the contents of heavy metals met the first class standard requiement of the Marine Sediment Quality except a few stations investigated in 2011 exceeded the first class standard.The contents of Hg and Cd were equal,which were obviously lower than that of the other five heavy metal elements.And the annual variations of the seven heavy metals were different from each other.The average single factor standard indices of the seven heavy metals were all less than 1,which indicated that the quality status of the surface sediment in the survey area was good.The order of the annual average single factor standard indices of the seven heavy metals was Cu＞Cr＞As＞Pb＞ Cd＞Hg＞Zn.And the standard index value of Cu was higher than the others,even the average standard index of Cu reached 0.61 in recent ten years,which should be paid attention to and strengthened routine monitoring.And the single factor standard indices for the other six heavy metal elements were all less than 0.4.Further potential ecological risk assessment results showed that the average potential ecological risk factors Eri of seven heavy metals of all cruises were less than 40,which presented a low level ecological risk.And the order of Eir for seven heavy metals in recent ten years was Hg＞Cd＞As＞Pb＞Cu＞Cr＞Zn,where Hg was the main potential ecological risk factor in the survey area.The annual variations of the comprehensive potential ecological risk index RI ranged from 32.18 to 53.12,which indicated a low level of ecological risk.Basically,the trend of the annual variations of RI was increasing first,then decreasing,and then a slight increasing.%根据2006-2014年共5个航次在黄河口附近海域采集的150个调查站位的表层沉积物样品的监测结果,对沉积物中Hg、Cu、Pb、Cd、Cr、Zn和As共7种重金属元素的含量及年际变化趋势进行了分析,采用单因子标准指数法和潜在生态风险指数法对重金属污染状况和潜在生态风险程度进行了评价.结果显示,7种重金属的含量除2011年少数调查站位的Cu和Pb超过第一类标准外,其他调查站位的重金属含量均符合海洋沉积物质量第一类标准.重金属Hg和Cd的含量相当,其含量明显低于其他5种重金属元素.7种重金属含量的年际变化有所不同,年平均单因子标准指数均小于1,表明调查海域表层沉积物质量状况良好.7种重金属元素的年平均单因子标准指数排序为Cu＞Cr＞As＞Pb＞Cd＞Hg＞Zn;其中,Cu的标准指数值较高,近10年来其标准指数均值达0.61,应引起重视并加强例行监测;其他6种重金属元素的单因子标准指数均值均小于0.4.潜在生态风险评价结果显示,各航次7种重金属的平均潜在生态风险系数Eir均小于40,属于低生态风险水平;7种重金属近10年平均Eir排序为Hg＞Cd＞As＞Pb＞Cu＞Cr＞Zn;其中,Hg是该调查海域的主要潜在生态风险因子.综合潜在生态风险指数RI的年际变化范围为32.18-53.12,属于低生态风险水平;RI的年际变化趋势基本表现为先升高后降低、然后略微上升的趋势.
展开▼
