摘要
本文选择沙蚕作为底栖生物,通过模拟海水养殖环境,研究在外源汞(Hg(NO_(3))_(2))胁迫下,沙蚕对汞(Hg)的甲基化和甲基汞(MeHg)的富集,以及沙蚕的生物应激响应.结果表明,海水养殖区沙蚕一方面自身具有将汞转化为MeHg的能力,同时沙蚕扰动会促进沉积物中Hg的甲基化,沙蚕扰动沉积物中MeHg的含量为无扰动沉积物中的1.93倍.随着外源汞含量和暴露时间的增加,沙蚕对MeHg的富集量逐渐增加,而富集速率逐渐降低.沙蚕体内MeHg富集含量为0.007~0.079mg/kg,占沙蚕体内总汞(THg)含量的31.20%~86.90%.与无机Hg相比,MeHg会对沙蚕造成更大的氧化压力,具有更强的生物毒性.沙蚕的SOD,CAT活性和GSH,MDA含量与暴露时间及含量有显著相关性.当沉积物中外源汞输入含量超过0.5mg/kg,沙蚕抗氧化应激系统将超过防御极限.
By simulation of mariculture environment and Nereis diversicolor as benthic,the methylation of Mercury(Hg),accumulation of methylmercury(MeHg)and the oxidative stress of Nereis diversicolor were studied under the existence of Hg(NO_(3))_(2).The results showed that mercury could be transformed to methylmercury by both Nereis diversicolor and the environment,especially in that with Nereis diversicolor.The concentration of MeHg in the sediments with Nereis diversicolor was 1.93 times that without Nereis diversicolor.With increasing of the external input mercury concentration and exposure time,the concentration of MeHg increased and the accumulation rate decreases gradually in benthic body.The concentration of methylmercury in Nereis diversicolor body was 0.007~0.079mg/kg that was 31.20%~86.90%of Total mercury.The activity of SOD and CAT,the concentration of GSH and MDA in the Nereis diversicolor were significantly correlated with exposed time and Hg concentration.Compared with inorganic Hg,Methylmercury could cause more oxidative stress and had stronger biotoxicity.The defense limit of the oxidative stress system of the silkworm would be broken,when the concentration of external input mercury exceeds 0.5mg/kg in the sediment.
作者
王书平
宋玉梅
刘爽
郭鹏然
WANG Shu-ping;SONG Yu-mei;LIU Shuang;GUO Peng-ran(Guangdong Provincial Engineering Research Center for Online Monitoring of Water Pollution,Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals,Institute of Analysis,Guangdong Academy of Sciences(China National Analytical Center,Guangzhou)Guangzhou 510070,China;Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第6期2871-2880,共10页
China Environmental Science
基金
国家自然科学基金资助项目(21777150)
国家重点研发计划资助项目(2018YFC1801701)。
关键词
外源汞
甲基化
沉积物
沙蚕
氧化应激
exogenous mercury
methylation
sediment
nereis diversicolor
oxidative stress
