斑马鱼幼鱼运动行为测试评价饮用水安全

饮用水安全直接关乎人类的健康与安全,当前迫切需要全新的毒性测试方法对饮用水的潜在人类健康风险进行全面、准确和灵敏的评估和预警。本研究以反渗透技术(RO)取代常用的固相萃取,分别浓缩饮用水厂的进厂水、出厂水和管网水进行毒性试验水样的前处理。反渗透技术前处理方法可以避免传统固相萃取方法中使用的有机溶剂对行为学测试体系的干扰。RO浓缩后的饮用水对斑马鱼胚胎进行持续暴露,采用Viewpoint行为测试软件量化分析出生后第6天(6 dpf)斑马鱼幼鱼的运动行为,选择运动距离和转向行为作为测试终点,分析进厂水、出厂水及管网水的潜在毒性及可能变化。结果表明,暴露在进厂水的幼鱼出现了明显的行为变化,尤其在较高浓度(20倍浓缩)暴露时,运动距离相比对照组显著减少,同时伴有剧烈的转向等异常行为;管网水对斑马鱼幼鱼行为存在一定程度的影响,而出厂水对幼鱼的运动行为没有显著影响。研究结果反映出当前饮用水厂深度处理工艺可以有效降低进厂水的潜在毒性和健康风险,但是经供水管网输送后,其水质可能发生了改变,导致管网水可能存在潜在的毒性。本研究所采用的反渗透技术前处理技术及斑马鱼幼鱼的运动行为学测试方法,可用于未来建立评估饮用水水质安全的早期预警系统。

Toxicity Assessment of Drinking Water Using Zebrafish Swimming Behavior Tests

The safety of drinking water is a critical issue for human health and society security. To evaluate the potential health risks of drinking water, it is essential to develop novel methodologies of toxicity tests with high sensitivity and accuracy. In the present study, reverse osmosis, instead of regular used solid-phase extraction technique, was used as the pretreatment method to concentrate inlet water, output water and tap water respectively, which could avoid the potential interference (induced by organic solvent during conventional solid-phase extraction process) to behavior tests. New-born zebrafish embryos were exposed to the concentrated drinking water till they developed to 6 days post-fertilization. Swimming behavior tests (locomotion and path angles) of the zebrafish larvae were then recorded and quantified by an analysis software Viewpoint to evaluate the potential toxicity induced by water borne exposure (including inlet water, output water and tap water). Our results revealed that the inlet water exposed zebrafish exhibited significant behavioral changes. Comparing with the control group, the larvae exposed to the highly concentrated (by 20 times) inlet water significantly reduced their locomotion, accompanied with dramatical and frequent changes of their swimming direction. Such behavioral changes were less evident for tap water exposed larvae, and not observed in outlet water exposed larvae. Our results revealed that the drinking water treatment process could effectively reduce the potential toxicity of inlet water. Nevertheless, it should be noted that the water supply network might change the water quality and induce toxicity of tap water. Moreover, swimming behavior tests of the zebrafish larvae followed by reverse osmosis technique could be applied to establish novel early-warning system for health risk assessment of drinking water.