Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Environ Pollut. 2018 Dec;243(Pt A):645-653. doi: 10.1016/j.envpol.2018.08.076. Epub 2018 Sep 7.
Organophosphate flame retardants (OPFRs), as alternatives to polybrominated biphenyl ethers (PBDEs), are frequently detected in various environmental matrices. Owing to urbanization and industrial pollution, co-contamination of OPFRs and heavy metals is ubiquitous in the environment. The toxicity of OPFRs in aqueous phase is a significant concern, but uncertainty still exists regarding the co-toxicity to benthic organisms of OPFRs and metals in sediments. Hence, we explored the physiological response of Corbicula fluminea to OPFRs and Cd in sediments. The results indicated that the antioxidant system in the clams was stimulated in the presence of OPFRs and Cd, and the oxidative stress increased with increasing concentrations of OPFRs. In contrast, the cytochrome P450 (CYP450) content and acetylcholinesterase (AChE) activity were reduced by exposure to both OPFRs and Cd. The cytochrome P450 4 family (CYP4) mRNA expression and OPFR toxicity were lower than those in previously reported experiments conducted in the water phase. Moreover, the expression levels of metallothionein (MT) and AChE mRNA decreased when OPFRs and Cd were present together. The highest integrated biomarker response (IBR) index (IBR = 15.41) was observed in the presence of 45 mg kg Cd + 200 mg kg OPFRs, rather than the 45 mg kg Cd + 400 mg kg OPFRs treatment (IBR = 9.48). In addition, CYP450 and AChE in the digestive glands of C. fluminea exhibited significant correlations with the concentration of the OPFR/Cd mixture (p < 0.01) and could be effective biomarkers for OPFR and Cd co-contamination. The results potentially contribute to more realistic predictions and evaluations of the environmental risks posed by OPFRs in aquatic sediments contaminated with heavy metals, particularly with respect to the risk to benthic organisms.
有机磷阻燃剂 (OPFRs) 作为多溴联苯醚 (PBDEs) 的替代品，经常在各种环境基质中被检测到。由于城市化和工业污染，OPFRs 和重金属在环境中普遍存在共污染。水相中 OPFRs 的毒性是一个重要的关注点，但对于沉积物中 OPFRs 和金属对底栖生物的共毒性仍然存在不确定性。因此，我们研究了 OPFRs 和 Cd 在沉积物中对河蚬生理反应的影响。结果表明，在存在 OPFRs 和 Cd 的情况下，河蚬的抗氧化系统受到刺激，随着 OPFRs 浓度的增加，氧化应激增加。相比之下，细胞色素 P450 (CYP450) 含量和乙酰胆碱酯酶 (AChE) 活性因暴露于 OPFRs 和 Cd 而降低。细胞色素 P450 4 家族 (CYP4) mRNA 表达和 OPFR 毒性低于以前在水相进行的实验报告。此外，当 OPFRs 和 Cd 同时存在时，金属硫蛋白 (MT) 和 AChE mRNA 的表达水平降低。在存在 45mgkg Cd+200mgkg OPFRs 的情况下，观察到最高的综合生物标志物响应 (IBR) 指数 (IBR=15.41)，而不是在存在 45mgkg Cd+400mgkg OPFRs 的情况下 (IBR=9.48)。此外，C. fluminea 消化腺中的 CYP450 和 AChE 与 OPFR/Cd 混合物的浓度呈显著相关 (p<0.01)，可作为 OPFR 和 Cd 共污染的有效生物标志物。研究结果可能有助于更真实地预测和评估受重金属污染的水生沉积物中 OPFRs 带来的环境风险，特别是对底栖生物的风险。
