广东沿岸牡蛎体内总汞含量变动趋势及其健康风险评价

为保障水产品质量安全和保护广东近岸海洋生态环境,于2004—2010年对广东沿岸17个主要港湾的海水养殖牡蛎进行了采样,运用原子荧光光谱法监测其总汞含量,并结合1989—1993年的历史监测数据分析了广东近岸海域总体及粤东、珠江口和粤西三大主要海区牡蛎体内汞的时空分布规律,应用单因子指数法和人体暴露风险系数法（HQ）评价了牡蛎体汞含量对人体暴露的健康风险。结果表明,1989—2010年广东沿海牡蛎体内汞含量的检出率为100%,变化范围为（0.080±0.114）mg·kg-（1湿重,下同）。单因子指数评价结果与风险系数（HQ）评价结果一致。上世纪80年代末（1989年）广东海域牡蛎体内汞含量处于污染水平,健康风险系数较大（HQ=3.39×10-2）;90年代（1991—1993年）牡蛎体内汞含量逐年降低,健康风险显著降低（HQ=2.23×10-2,P〈0.05）;2004年以来,全海域的牡蛎体内汞含量一直稳定地维持在较低水平（0.012±0.006）mg·kg-1];粤东、珠江口海域牡蛎体内含量稳定下降,粤西海域降幅有所减小。2006—2010年,人均摄取牡蛎软组织20g·d-1,每年食用200d,食用20a后,在人均寿命70岁的时间内,其健康风险系数HQ为0.13×10-2,食用安全,不存在潜在的危害性,食用广东沿海牡蛎对人体日均总汞允许摄入限量的贡献率仅为0.13%。

Spatial-temporal Trends and Health Risk Assessments of Total Mercury in the Oysters from Guangdong Coastal Bays,China

To ensure the quality and safety of seafood products and provide clues for the protection of marine environments from Guangdong coastal waters,concentrations of total mercury in the soft tissues of oysters were collected from 17 important Guangdong estuaries/bays in March from 2004 to 2010 respectively,and were analyzed using atomic fluorescence spectrometry.Combined with the monitoring data on mercury level in oysters in these waters during 1989 to 1993,the paper analyzed the spatial and temporal trends of mercury content in oysters from Guangdong coastal waters.In addition,the Single Factor Index（SI） and Hazard Quotient（HQ） methods were used for the assessments of health risk of oysters to human.The results showed that all stations/samples were found within the limits for mercury standards as set by the FAO,though 100 percent of mercury in oysters was detected.The annual mercury content in oysters has decreased significantly since 1989,which averaged（0.080±0.114）mg·kg-1 wet weight in total.The results of health risk assessment indicated that both the SI and HQ well reflected the similar trends.The HQ was 3.39×10-2 in 1989,and decreased significantly to 2.23×10-2 during 1991 and 1993.And since 2004,the concentration of mercury has been well within a lower level（0.012±0.006）mg·kg-1 wet weight],with the comparative slower decrease of mercury content in West Guangdong waters than the other two districts.And the HQ during 2006 and 2010 averaged 0.13×10-2,which was far lower than the HQ threshold（1.0）,therefore the mercury level of oysters from Guangdong coastal waters was safe and had no possible hazards to health.