State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Ecotoxicol Environ Saf. 2014 Apr;102:129-35. doi: 10.1016/j.ecoenv.2014.01.010. Epub 2014 Feb 14.
Rapid urbanization has caused potential pollution of heavy metal in Shanghai. A comprehensive pollution study of heavy metals (Cd, Cu, Pb, and Zn) in 35 lake surface sediments from city parks in the four different urbanized areas of Shanghai was conducted. Intensive human activities caused moderate enrichment of the four metals in highly urbanized areas, especially Cd with the significant enrichment in the central urban core area. However, the levels of the four metals in all the sediments were lower than the corresponding consensus-based Probable Effect Concentration, indicating adverse effects not to occur frequently. The integrated pollution assessments of multiple heavy metals also suggested low ecological risk and 15-29 percent probability of toxicity in most of sediments. The metal speciation analysis showed that Cd, Cu, Pb, and Zn were dominated by the non-residual fractions and thus they have high mobility and bioavailability, indicating significant anthropogenic sources. According to the Risk Assessment Code, Cd had the highest bioavailable fraction and represented high or very high risk, followed by Zn with medium or high risks in most of samples, while no or low risk was found for Cu and Pb at most sites because they were dominated by reducible and residual fractions. Correlation analysis showed that chemical fractions of heavy metals were prone to transform among each other if environmental conditions changed. Therefore, in view of anthropogenic inputs and speciation distribution, heavy metals with very high bioavailability at very low total levels and those with low bioavailability at very high total levels should not be ignored.
快速的城市化进程导致上海重金属潜在污染。对上海市四个不同城市化区域的 35 个城市公园湖表层沉积物中的重金属（Cd、Cu、Pb 和 Zn）进行了全面的污染研究。高强度的人类活动导致这四种金属在高度城市化地区中度富集，尤其是在城市核心区的 Cd 出现了显著的富集。然而，所有沉积物中的四种金属含量均低于相应基于共识的可能效应浓度，表明不会频繁发生不良影响。多种重金属的综合污染评估也表明，大部分沉积物的生态风险较低，毒性发生的概率为 15-29%。金属形态分析表明，Cd、Cu、Pb 和 Zn 主要以非残留态为主，因此具有较高的迁移性和生物可利用性，表明存在显著的人为来源。根据风险评估准则，Cd 具有最高的生物可利用分数，代表高或极高风险，其次是 Zn，在大多数样品中为中或高风险，而 Cu 和 Pb 则在大多数位点未发现或低风险，因为它们主要以可还原和残留态为主。相关性分析表明，如果环境条件发生变化，重金属的化学形态易于相互转化。因此，鉴于人为输入和形态分布，应重视那些总水平极低而生物可利用性极高，或总水平极高而生物可利用性极低的重金属。
