Gagné F, André C, Cejka P, Hausler R, Fournier M, Blaise C
Fluvial Ecosystem Research, Environment Canada, Montréal, Quebec, Canada.
Ecotoxicol Environ Saf. 2008 Mar;69(3):366-73. doi: 10.1016/j.ecoenv.2007.10.027. Epub 2008 Feb 20.
The immunotoxic potential of a primary-treated municipal effluent following enhanced disinfection by ozonation was studied in the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations (0%, 1%, 3%, 10%, and 20% v/v) of the effluent before and after ozone treatment (approximately 10 mg/L of purged O(3)) in a continuous flow-through laboratory for 7 weeks. Immunocompetence was appraised by measuring phagocytosis, cell viability (fluorescein retention), cell adherence to polystyrene micro-wells, cyclooxygenase (COX) activity and total nitrite levels in peripheral hemocytes from the hemolymphs. The results showed that phagocytosis was significantly inhibited by the primary-treated effluent at a threshold concentration of 1.7% v/v. Cell viability was also significantly reduced three-fold compared to controls at the same effluent threshold concentration, but hemocyte adherence was unchanged. COX activity was increased 1.3-fold at a threshold concentration of 14% v/v. Total nitrite levels were significantly increased 2.2-fold at a threshold concentration of 5.5% v/v. Ozone treatment of the effluent was not successful in removing phagocytic inhibition, but did completely remove cytotoxicity from hemocytes. Ozonation also reduced cell adherence at a threshold concentration of 1.7% v/v. The inflammatory properties of the effluent appeared to be accentuated by the ozone, as evidenced by an increase in COX activity, which reached 2.6-fold activity compared to controls, as compared to the 1.3-fold increase witnessed in the primary-treated effluent. Furthermore, total nitrite levels reached a two-fold induction at a threshold concentration of 1.7% v/v in the ozone-enhanced effluent compared to 5.5% v/v in the primary-treated effluent. In conclusion, ozonation of a primary-treated effluent successfully reduced microbial loading and completely removed cytotoxicity, but increased the inflammatory properties of the effluent. Investigations aimed at examining the impacts of sustained inflammation on the host's capacity to remove potentially pathogenic bacteria are recommended.
在淡水贻贝椭圆萝卜螺中研究了经臭氧强化消毒的一级处理城市污水的免疫毒性潜力。在连续流动的实验室中，将贻贝暴露于臭氧处理前后（约10mg/L吹扫过的O(3)）浓度不断增加（0%、1%、3%、10%和20% v/v）的污水中7周。通过测量吞噬作用、细胞活力（荧光素保留）、细胞对聚苯乙烯微孔的粘附、环氧化酶（COX）活性以及血淋巴中外周血细胞中的总亚硝酸盐水平来评估免疫能力。结果表明，在阈值浓度为1.7% v/v时，一级处理污水显著抑制吞噬作用。在相同污水阈值浓度下，细胞活力也比对照组显著降低了三倍，但血细胞粘附没有变化。在阈值浓度为14% v/v时，COX活性增加了1.3倍。在阈值浓度为5.5% v/v时，总亚硝酸盐水平显著增加了2.2倍。对污水进行臭氧处理未能消除吞噬抑制作用，但确实完全消除了血细胞的细胞毒性。臭氧处理在阈值浓度为1.7% v/v时也降低了细胞粘附。污水的炎症特性似乎因臭氧而加剧，这表现为COX活性增加，与对照组相比达到2.6倍活性，而在一级处理污水中观察到的增加为1.3倍。此外，与一级处理污水中5.5% v/v的阈值浓度相比，臭氧强化污水在阈值浓度为1.7% v/v时总亚硝酸盐水平达到两倍诱导。总之，对一级处理污水进行臭氧处理成功降低了微生物负荷并完全消除了细胞毒性，但增加了污水的炎症特性。建议开展旨在研究持续炎症对宿主清除潜在致病细菌能力影响的调查。
