Tsai Kuo-Pei, Chen Chung-Yuan
Institute of Environmental Engineering, National Chiao Tung University, Taiwan.
Environ Toxicol Chem. 2007 Sep;26(9):1931-9. doi: 10.1897/06-612R.1.
The current study presents the toxicity data of 90 organic compounds with various modes of actions to Pseudokirchneriella subcapitata. The assessment was conducted using a closed-system technique, and a biomass-type end point based on the cell density was employed. The above toxicity data were compared with test results from ciliate (Tetrahymena pyriformis), water flea (Daphnia magna), fish (Pimephales promelas), and luminescent bacteria (Photobacterium phosphoreum). Satisfactory correlation relationships between toxicity data from algae and other aquatic organisms were found (r2 = 0.66-0.82). Pseudokirchneriella subcapitata revealed considerably higher sensitivity to organic toxicants compared with other organisms. Benzenes, aldehydes, and alkanes also were highly selective to the test alga. In addition, the results show that conventional algal batch tests tend to underestimate the toxicity of organic compounds, except in the case of 4-chlorophenol. Toxicity observed from the closed-system test is approximately 2- to 380-fold higher than that estimated by conventional batch tests. Such a phenomenon can be found in nearly all organic compounds, regardless of the chemical's Henry's law constant. In the risk assessment of chemicals, following the European Union's practice, approximately 30% (7 of 23) of the cases may result in a more strict classification when the batch test is replaced by the closed-system test. More effort therefore is needed to revise the algal toxicity database using the closed-system test method.
本研究给出了90种具有不同作用方式的有机化合物对小新月菱形藻的毒性数据。评估采用封闭系统技术进行，并采用基于细胞密度的生物量型终点指标。将上述毒性数据与纤毛虫（梨形四膜虫）、水蚤（大型溞）、鱼类（黑头软口鲦）和发光细菌（明亮发光杆菌）的测试结果进行了比较。发现藻类与其他水生生物的毒性数据之间存在良好的相关性（r2 = 0.66 - 0.82）。与其他生物相比，小新月菱形藻对有机毒物的敏感性要高得多。苯、醛和烷烃对受试藻类也具有高度选择性。此外，结果表明，除4-氯苯酚外，传统的藻类批量试验往往会低估有机化合物的毒性。封闭系统试验观察到的毒性比传统批量试验估计的毒性高约2至380倍。几乎所有有机化合物都会出现这种现象，无论该化学品的亨利定律常数如何。在化学品风险评估中，按照欧盟的做法，当用封闭系统试验取代批量试验时，约30%（23例中的7例）可能会导致更严格的分类。因此，需要付出更多努力，使用封闭系统试验方法来修订藻类毒性数据库。
