山东近岸海域表层沉积物7种重金属污染特征和生态风险评估研究

CONTAMINANT CHARACTERISTICS AND ECOLOGICAL RISK ASSESSMENT ON POLLUTION BY SEVEN HEAVY METALS IN SURFACE SEDIMENTS IN SHANDONG COASTAL AREAS

本文综合运用单因子污染指数法、Hakanson潜在生态风险指数法和沉积物质量基准法3种方法,研究和评价了2012年和2013年山东近岸海域表层沉积物重金属的污染特征和潜在生态风险。结果表明:山东近岸海域94%以上站位的表层沉积物重金属含量符合第一类海洋沉积物质量标准,沉积物质量良好;山东近岸海域重金属综合潜在生态风险低,各重金属潜在生态风险由高到低为Hg>As>Cd>Pb>Cu>Cr>Zn(2012年)和Hg>Cd>As>Pb>Cu>Cr>Zn(2013年),Hg在个别站位达中潜在生态风险程度,为主要污染因子;50%以上站位As含量介于美国佛罗里达州和加拿大沉积物质量基准的TEL—PEL之间,表明负面生物效应偶尔发生。应加强对山东近岸海域表层沉积物中重金属Hg和As的监测,重点关注二者相对高值区的潜在生态风险和负面生物效应。

With field observation data of heavy metal pollution in surface sediments in Shandong coastal areas in 2012 and 2013, we assessed the ecological risk in these areas by adopting three different indices, i.e., single factor index(SFI), Hakanson's potential ecological risk index(PERI), and sediment quality guidelines(SQG). The results show that among 38 monitoring stations, 94% of them were in rather good status whose heavy metal contents in surface sediments comply with the national first-class benchmark in marine sediment quality. The heavy metals were at the low level of comprehensive potential ecological risk, in descending order of Hg>As>Cd>Pb>Cu>Cr>Zn(in 2012) and Hg>Cd>As>Pb>Cu>Cr>Zn(in 2013). Mercury was determined as the principal pollution factor, as its potential ecological risk was moderate in few stations; arsenic contents were between the TEL(threshold effect level) and PEL(probable effect level) in American(Florida) and Canadian guidelines in over half of the stations, showing occasional adverse biological effects. Therefore, close watchout and stringent control shall be taken to prevent mercury and arsenic pollutions, and special attentions shall be paid to potential ecological risk and adverse biological effects in the coastal areas to lower relatively high values.