Purpose

Sediment Quality Guidelines (SQGs) are the standard for protecting organisms from chemical hazards. Species Sensitivity Distribution (SSD), a typical derivation method of the SQGs, has been widely used for organic pollutants, whereas there are few studies applied on metals. This study investigated the toxic effects of Cu, Cd, Zn, and Pb to Limnodrilus hoffmeisteri and Chironomus larvas, obtained the SQGs by the SSD method, and evaluated the ecological risks of Poyang Lake, China.

Materials and methods

The test endpoints of L. hoffmeisteri (mortality and autotomy rates) and C. larvas (mortality and growth inhibition rates) after 21- and 14-day exposure of Cu, Cd, Zn, and Pb in the sediments of Poyang Lake were conducted, respectively. The SSD method was used for the curve optimal fitting and the SQG calculation based on the biotoxicity data of the local species in Poyang Lake. The ecological risk of Poyang Lake was assessed by calculating the potential ecological risk index (RI). The toxicity quotient Q was used for the SQGs verification of Cu, Cd, Zn, and Pb.

Results and discussion

According to the results of toxicity tests, C. larvas are more sensitive to the stress effects of heavy metals compared to L. hoffmeisteri. The Criteria Continuous Concentration (CCC) of Cu, Cd, Zn, and Pb were 34.9, 0.5, 58.2, and 35.0 mg kg⁻¹, respectively. The Criteria Maximum Concentration (CMC) of Cu, Cd, Zn, and Pb were 56.35, 2.0, 151.3, and 175.0 mg kg⁻¹, respectively. We selected C. larvas as experimental organisms to verify the SQGs and the results conformed to the meaning of guidelines. The RI values for heavy metals in all sampled sediments (P1 to P10) showed low potential ecological risks (RI < 120), except P2, P6, and P10. High potential ecological risks (RI > 120) of P2, P6, and P10 are mainly attributed to Cd.

Conclusions

In general, the CCC and CMC of Cu, Cd, Zn, and Pb conformed to the meaning of guidelines. The ecological risk index method showed that Poyang Lake was slightly polluted by Cu, Zn, and Pb, while heavily polluted by Cd. The results of the SQGs of heavy metals and ecological risk assessment can provide theoretical support for monitoring heavy metal pollution and biodiversity protection in Poyang Lake.

中文翻译：

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Po阳湖重金属对沉积物中淡水底栖生物的毒性作用及质量指导原则研究

目的

沉积物质量指南（SQG）是保护生物免受化学危害的标准。物种敏感度分布（SSD）是SQG的一种典型推导方法，已广泛用于有机污染物，而对金属的研究很少。本研究调查了铜，镉，锌和铅对Li草和Chi幼虫的毒性作用，通过SSD方法获得了SQG，并评估了Po阳湖的生态风险。

材料和方法

在Po阳湖沉积物中暴露铜，镉，锌和铅21天和14天后，对霍夫麦斯特利氏菌（死亡率和自体截肢率）和幼虫毛囊虫（死亡率和生长抑制率）进行了测试终点，分别。基于Po阳湖当地物种生物毒性数据，采用SSD法进行曲线的最佳拟合和SQG的计算。通过计算潜在的生态风险指数（RI）来评估of阳湖的生态风险。毒性商Q用于Cu，Cd，Zn和Pb的SQG验证。

结果和讨论

根据毒性测试的结果，与霍夫迈斯特氏菌相比，幼虫对重金属的胁迫效应更为敏感。Cu，Cd，Zn和Pb的标准连续浓度（CCC）分别为34.9、0.5、58.2和35.0 mg kg ^-1。Cu，Cd，Zn和Pb的标准最大浓度（CMC）分别为56.35、2.0、151.3和175.0 mg kg ^-1。我们选择了幼虫作为实验生物来验证SQG，并且结果符合指南的含义。除P2，P6和P10外，所有采样沉积物中（P1至P10）的重金属RI值均显示出较低的潜在生态风险（RI <120）。P2，P6和P10的高潜在生态风险（RI> 120）主要归因于Cd。

结论

通常，Cu，Cd，Zn和Pb的CCC和CMC符合准则的含义。生态风险指数法表明，Po阳湖的铜，锌，铅污染较轻，而镉的污染较重。重金属的SQG结果和生态风险评估可以为can阳湖重金属污染监测和生物多样性保护提供理论支持。