水环境因子对镧系元素生物毒性效应的影响  

Effects of water environmental factors on the biological toxicity of lanthanides

作　　者：孙梨宗 郭橙[1] 台培东 SUN Li-zong;GUO Cheng;TAI Pei-dong(School of Environment and Safety Engineering,Liaoning Petrochemical University,Fushun 113001,Liaoning,China;Key Laboratory of Pollution Ecology and Environmental Engineering,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]辽宁石油化工大学环境与安全工程学院,辽宁抚顺113001 [2]中国科学院污染生态与环境工程重点实验室,中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2022年第5期955-962,共8页Chinese Journal of Ecology

基　　金：国家重点研发课题(2018YFC1800703);国家自然科学基金项目(41877146和31600372)资助。

摘　　要：镧系元素(稀土)应用的不断拓展引起了人们对其生物安全性的关注。为探明环境因素对镧系元素生物毒性效应的影响,以斑马鱼(Danio rerio)为受试生物,研究水环境因子(pH、HCO_(3)^(-)、Ca^(2+)-Mg^(2+)、K^(+)和Cl^(-)等)对镧系元素生物毒性和生物蓄积性的影响,分析不同水环境条件下4种代表性镧系元素(La、Ce、Gd和Ho)的毒性大小及其趋势。结果表明:在标准水中,La对斑马鱼成鱼的96 h-LC50为165.6μmol·L^(-1),毒性大小与水中pH、HCO_(3)^(-)和Ca^(2+)-Mg^(2+)浓度显著相关,其斜率分别为0.912、1.135和0.222,而与水中Cl^(-)、Na^(+)、K^(+)和SO_(4)^(2-)的浓度无显著性关系;4种镧系元素均可在测试开始阶段与HCO_(3)^(-)络合形成沉淀颗粒,pH的降低或HCO_(3)^(-)的减少可促进颗粒态镧系元素向可溶态转化,从而增强其生物毒性和生物蓄积性;在pH 5.0和HCO_(3)^(-)0.2 mmol·L^(-1)(排除沉淀影响)条件下,4种镧系元素呈现毒性一致的趋势(对斑马鱼的96 h-LC50为6.11~6.43μmol·L^(-1));可见,在标准水中,4种镧系元素毒性的差异可能是由于单个元素的有效态差异而不是元素的不同毒性所致。因此,在生物毒性机制的差异被揭露之前,镧系元素可视为一组具有毒性相加模式的元素进行生物毒性评估,评估过程应注重pH和碳酸盐的影响。The expansion of the application of lanthanides(rare earth elements)has aroused wide attention to their biological safety.To explore the effects of environmental factors on the biological toxicity of lanthanides,using zebra fish(Danio rerio)as the test organism,we examined the effects of water environmental factors(pH,HCO_(3)^(-),Ca^(2+)-Mg^(2+),K^(+),Cl^(-),etc.)on biological toxicity and bioaccumulation of lanthanides,and analyzed the toxicity levels and trends of four representative lanthanides(La,Ce,Gd and Ho)under different water environmental conditions.The results showed that in standard water,the 96 h-LC50 of La to adult Danio rerio was 165.6μmol·L^(-1).Its toxicity was significantly related to pH,HCO_(3)^(-)and Ca^(2+)-Mg^(2+) in the water,with its slopes being 0.912,1.135 and 0.222,respectively,and had little relationship with Cl^(-),Na^(+),K^(+)and SO_(4)^(2-).At the beginning of the test,the four lanthanides could be complexed with HCO_(3)^(-) to form precipitated particles.A decrease in pH or HCO_(3)^(-) could promote the conversion of lanthanides from granular state to soluble state,with enhanced biological toxicity and bioaccumulation.Under the conditions of pH 5.0 and HCO_(3)^(-)0.2 mmol·L^(-1)(excluding the influence of lanthanide precipitation),four lanthanide elements showed a consistent trend of toxicity(6.11-6.43μmol·L^(-1) of 96 h-LC50 for Danio rerio).We speculate that the difference in the toxicity of the four lanthanide elements in standard water may be due to the difference in the effective state of a single element rather than the different toxicity of the elements.Therefore,before the differences in biological toxicity mechanisms are revealed,lanthanides can be considered as a group of elements with a toxicity additive model for biological toxicity assessment.The evaluation process should focus on the effects of pH and carbonates.

关 键 词：镧系元素 斑马鱼 毒性效应 环境因子 作用模式 

分 类 号：X171.5[环境科学与工程—环境科学]