2008年珠江口表层沉积物重金属含量及生态危害评价

Heavy metals content in surface sediment in the Pearl River Estuary and potential ecological risk assessment

2008年5、8月针对珠江口表层沉积物重金属的空间分布、相关性、超标倍数和超标率等进行了研究,并采用综合污染指数法和Hakanson潜在生态危害指数法对其污染特征和生态危害进行了评价。结果显示:研究期间珠江口表层沉积物中重金属Cu为63.2 mg/kg、Zn为261.0 mg/kg、Pb为96.7 mg/kg、Cd为6.7 mg/kg、Cr为167.4 mg/kg。同一口门5种重金属相关极显著(P<0.01);每种重金属含量在各口门间相关极显著,表明其具有较强的同源性。珠江口水域重金含量表现出整体的超标现象,超标率均不低于87.5%,Cd超标倍数最大。综合污染指数法评价显示,重金属污染处重度水平,潜在生态危害指数法显示,重金属潜在生态危害处于较严重水平;Cd对污染和潜在生态危害贡献率最大。

Spatial distribution,correlation,multiples beyond standards,unattainment rate of heavy metals in the Pearl River Estuary were studied in May and April 2008,and general pollution index and Hakanson potential ecological risk index were used to evaluate their pollution characteristics and ecological risk.The results showed that the mean contents heavy metals were Cu 63.2 mg/kg,Zn 261.0 mg/kg,Pb 96.7 mg/kg,Cd 6.7 mg/kg,Cr 167.4 mg/kg.Pearson correlation analysis showed that heavy metals were significantly correlated;all the heavy metals were beyond standards,and the unattainment rates were high;General pollution index and potential ecological risk index showed that the studied area was seriously polluted by metals;Among the heavy metals,Cd was the most serious factor.