Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.
State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Environ Sci Technol. 2024 Aug 20;58(33):14618-14628. doi: 10.1021/acs.est.4c02026. Epub 2024 Aug 9.
Bivalves are often employed for biomonitoring contaminants in marine environments; however, in these large-scale programs, unavoidably, using multiple species presents a significant challenge. Interspecies differences in contaminant bioaccumulation can complicate data interpretation, and direct comparisons among species may result in misleading conclusions. Here, we propose a robust framework based on toxicokinetic measurements that accounts for interspecies differences in bioaccumulation. Specifically, via a recently developed double stable isotope tracer technique, we determined the toxicokinetics of cadmium (Cd)─a metal known for its high concentrations in bivalves and significant interspecies bioaccumulation variability─in six widespread bivalve species including mussels (, , ) and oysters (, , ). Results show that oysters generally have higher Cd uptake rate constants (: 1.18-3.09 L g d) and lower elimination rate constants (: 0.008-0.017 d) than mussels (: 0.21-0.64 L g d; : 0.018-0.037 d). The interspecies differences in tissue Cd concentrations are predominantly due to Cd uptake rather than elimination. Utilizing toxicokinetic parameters to back-calculate Cd concentrations in seawater, we found that the ranking of Cd contamination levels at the six sites markedly differs from those based on tissue Cd concentrations. We propose that this approach will be useful for interpreting data from past and future biomonitoring programs.
双壳类动物常用于海洋环境中污染物的生物监测；然而，在这些大规模的项目中，不可避免地，使用多种物种会带来重大挑战。污染物生物积累的种间差异会使数据解释变得复杂，而且物种之间的直接比较可能会导致误导性的结论。在这里，我们提出了一个基于毒代动力学测量的稳健框架，该框架考虑了生物积累中的种间差异。具体来说，通过最近开发的双重稳定同位素示踪技术，我们确定了六种广泛分布的双壳类物种（包括贻贝、牡蛎和扇贝）中镉（一种以高浓度存在于双壳类动物和显著的种间生物积累变异性而闻名的金属）的毒代动力学。结果表明，与贻贝相比，牡蛎通常具有更高的镉摄取率常数（1.18-3.09 L g d）和更低的消除率常数（0.008-0.017 d）（0.21-0.64 L g d；0.018-0.037 d）。组织中 Cd 浓度的种间差异主要归因于 Cd 的摄取而非消除。利用毒代动力学参数来反算海水中的 Cd 浓度，我们发现，在六个地点的 Cd 污染水平的排名与基于组织 Cd 浓度的排名明显不同。我们建议，这种方法将有助于解释过去和未来生物监测计划的数据。
