5种多溴联苯醚同系物对海洋饵料藻(亚心型扁藻和盐生杜氏藻)的急性毒性

Acute toxicity of five brominated diphenyl ether congeners to marine bait-algae species: Platymonas subcordiformis and Dunaliella saliva

本研究选择5种多溴联苯醚同系物（BDE-28、BDE-47、BDE-99、BDE-153和BDE-209）对2种海洋饵料藻（亚心型扁藻和盐生杜氏藻）进行急性毒性试验。96 h半抑制浓度（96 h EC50）计算结果表明,BDE-28和BDE-47的毒性较高,随溴原子取代数的增加,PBDE同系物对海洋饵料藻的毒性呈下降趋势,5种PBDE同系物对亚心形扁藻、盐生杜氏藻的96 h EC50由小及大依次为：BDE-28（128,75μg/L）、BDE-47（114,120μg/L）、BDE-99（383,572μg/L）、BDE-153（996,1249μg/L）和BDE-209（2056,1868μg/L）。目前全球近岸海水中PBDEs浓度尚不会对海洋饵料藻产生急性毒性。海洋微藻对同种PBDE同系物的敏感性差异较大（96 h EC50相差1~2个数量级）,为客观评价PBDEs的海洋生态风险性,应研究PBDEs对更多种类微藻的毒性效应。

In this study, acute toxicity test was used to identify the effects of five PBDE congeners, named BDE-28, BDE-47 ,BDE-99 ,BDE-153 and BDE-209, to two species of marine microalgae, Platymonas subcordiformis and Du- naliella saliva, in the laboratory. The 96-h median effective concentration （96 h ECso ） for each species was calculat- ed. The results showed that BDE-28 and BDE-47 were particularly toxic to marine bait-algae and the toxicity of PBDE congeners decreased with the amount of Br atoms in the congener molecule. Ranking 96 h ECso for both P. subcordifor- m/s and D. saliva was BDE-28（128,75 μg/L） 〈 BDE-47（l14,120 μg/L） 〈 BDE-99（383,572 μg/L） 〈 BDE- 153 （996,1249 μg/L） 〈 BDE-209 （2056,1868 μg/L） . The coastal PBDEs level in the world is not enough to induce significant acute toxicity to marine bait-algae. In addition, the sensitivity of microalgae to a given congener was specific to species ,with the difference of 96 h ECso by one or two order of magnitude. Therefore acute tests with more species should be performed for evaluating objectively the ecological risk of PBDEs in coastal area.