1989～2010年广东沿海牡蛎体内Pb的时空分布及风险评价

Characteristics of spatial-temporal distribution and risk assessment of Pb in oysters along the coast of Guangdong Province from 1989 to 2010

通过对1989～2010年广东沿岸15个采样点牡蛎体内Pb含量的监测和有关历史资料,分析了粤东、珠江口和粤西沿岸海域牡蛎体内Pb的时空分布特征,并采用单因子指数和非致癌性风险指数法(NCHI)评价了Pb的食用风险.结果表明,广东沿海牡蛎体内Pb的浓度范围为N.D.～3.65mg/kg,总体平均值为0.41mg/kg,从总体看其出现频数呈偏正态分布.牡蛎体内Pb的年际变化呈现逐渐降低的趋势,从2001年后波动趋于平缓并有微弱的上升;其空间分布特征表现为珠江口>粤西≥粤东的变化规律,具体表现为粤东和粤西牡蛎体内Pb浓度随时间延长均表现为明显的下降趋势,珠江口牡蛎体内Pb浓度从2006～2010年开始有明显的下降.单因子指数和非致癌性风险指数评价结果均表明,广东沿岸牡蛎体内Pb的浓度未产生明显污染,对人体不具有非致癌性风险.

Spatial-temporal distributions of Pb in oysters in Guangdong coastal waters were monitored from 1989 to 2010.The methods of single factor index and the non-carcinogenic hazard index were applied to access the hazard risk of Pb in oysters from the coastal waters.The concentration of Pb in oysters ranged from no detectable to 3.65mg/kg with an overall average of 0.41mg/kg,and showed a logarithmic normal distribution on the whole.Annual variations in the concentration of Pb in oysters decreased gradually and then tended to be stable with a weak ascending trend.The concentration of Pb in oysters dropped obviously from the coastal waters of eastern Guangdong and western Guangdong every five years,but which showed an obvious decrease from the Pearl River estuary over the period of 2006-2010.Moreover,spatial distribution of concentration of Pb in oysters varied in the following order： the Pearl River estuary the west Guangdong coastal waters the east Guangdong coastal waters.The single factor index and non-carcinogenic hazard index of Pb in oysters were well below 1.0 according to all the related standards issued by China,EU and Hongkong,respectively,which indicated no possible hazard risk in consuming the oysters collected from Guangdong coastal waters.