Wang Zaosheng, Kong Hainan, Wu Deyi
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Arch Environ Contam Toxicol. 2007 Jul;53(1):50-6. doi: 10.1007/s00244-006-0206-0. Epub 2007 May 4.
The objective of this study was to evaluate the sensitivity of a saltwater cladoceran Moina monogolica Daday to copper toxicity. Acute and chronic toxicity tests were conducted according to the American Society for Testing and Materials (ASTM) guidelines. The 24- and 48-h LC(50)s and their 95% confidence intervals (CIs) were calculated as 154.21 (135.50-182.05) microg Cu/L and 106.07 (99.77- 112.36) microg Cu/L , respectively, based on measured copper concentrations. When compared with different phyla or classes of estuarine organisms, M. monogolica had moderate sensitivity and was suitable to be used as an indicator organism in the Changjiang estuary. Eight end points of longevity, number of broods, brood size, total reproduction, time to first brood, intrinsic rate of natural increase (r(m)), net reproductive rate (R(0)), and mean generation time (T) used to evaluate chronic effects were affected at chronic copper concentrations. Comparisons of chronic effects showed that toxicity mechanisms of dissolved copper are different from those of dietary exposure. The EC(20)s, EC(50)s, and their 95% CIs of end points were calculated using linear regression equations. The geometric mean generated the maximum-acceptable-toxicant concentration of 6.74 microg Cu/L between the no-observed-effect concentration of 5.06 and the lowest-observed-effect concentration of 8.99 microg Cu/L for brood size, total reproduction, r(m), and R(0), and 12.1 microg Cu/L between 8.99 and 16.29 microg Cu/L for longevity and number of broods as the end points, respectively. The EC(20) of R(0) appeared to be the most sensitive at 3.82 microg Cu/L among the end points. Results showed that aquatic organisms were possibly negatively affected at sites of higher copper concentrations in the Changjiang estuary. Further research is needed to evaluate the direct or indirect effects of copper more comprehensively to protect aquatic organisms and their habitats in the Changjiang estuary.
本研究的目的是评估盐水枝角类蒙古裸腹溞对铜毒性的敏感性。根据美国材料与试验协会（ASTM）指南进行急性和慢性毒性试验。基于测得的铜浓度，计算出24小时和48小时的半数致死浓度（LC(50)）及其95%置信区间（CI）分别为154.21（135.50 - 182.05）μg Cu/L和106.07（99.77 - 112.36）μg Cu/L。与河口不同门类或纲的生物相比，蒙古裸腹溞具有中等敏感性，适合作为长江口的指示生物。用于评估慢性影响的寿命、繁殖代数、每窝幼体数、总繁殖量、首次繁殖时间、内禀自然增长率（r(m)）、净繁殖率（R(0)）和平均世代时间（T）这八个终点指标在慢性铜浓度下均受到影响。慢性影响的比较表明，溶解铜的毒性机制与饮食暴露的毒性机制不同。终点指标的20%效应浓度（EC(20)）、50%效应浓度（EC(50)）及其95% CI使用线性回归方程计算得出。以每窝幼体数、总繁殖量、r(m)和R(0)为终点指标时，几何平均值得出最大可接受毒物浓度为6.74 μg Cu/L，介于未观察到效应浓度5.06 μg Cu/L和最低观察到效应浓度8.99 μg Cu/L之间；以寿命和繁殖代数为终点指标时，最大可接受毒物浓度分别为12.1 μg Cu/L，介于8.99 μg Cu/L和16.29 μg Cu/L之间。在终点指标中，R(0)的EC(20)似乎最敏感，为3.82 μg Cu/L。结果表明，长江口中铜浓度较高的区域可能会对水生生物产生负面影响。需要进一步研究以更全面地评估铜的直接或间接影响，从而保护长江口的水生生物及其栖息地。
