监测水体重金属污染的分子生物标志物研究进展

Progress in molecular biomarkers for monitoring heavy metal pollution of water system

水体重金属污染具有持久性、高度危害性和难治理性,如何快速、准确监测并对其进行科学评价,成为当今环境科学关心的热点问题。大量研究表明,水生生物体内某些生理指标的变化可以反映水体重金属的污染程度。综述了乙酰胆碱酯酶、抗氧化防御系统、腺苷三磷酸、DNA损伤以及金属硫蛋白等几种分子水平上的生物标志物监测重金属污染的原理、国内外研究进展以及应用现状。认为分子生物标志物具有特异性、敏感性等优势,可以较快指示水体重金属污染对生物体的影响,在实际应用中需注意各种干扰因素。在进行野外研究时,要注重混合重金属与多途径暴露下,分子生物标志物的变化规律。生物体之间差异性会导致标志物在同样暴露条件下产生不同的变化规律,需要加强"离体"标志物和"标准化"标志物的研究,确保监测结果的可靠性和可重复性。生物标志物较为敏感,容易受到外界环境及体内生理因素影响,可考虑综合运用多种生物标志物指示重金属污染。目前,有关重金属对水生生物毒性效应的研究较多,但重金属对生物体的致毒机理方面研究并不深入,这将是今后研究的重点问题之一。

Great concerns are focused on monitoring and evaluating heavy metal pollution in water due to its characteristics,such as persistent,harmful and difficult to control.A large number of studies have shown that changes of certain physiological indexes in aquatic organisms can reflect the degree of heavy metal pollution in water.In this paper,we overview principle,research and application status of several molecular biomarkers for evaluating heavy metal pollution,such as acetylcholinesterase,antioxidant enzyme,adenosine triphosphate,DNA damage and metallothionein etc.Results show that molecular biomarkers can indicate effects of heavy metal on aquatic organisms for their specificity and sensitivity.However,various interference factors need to be taken into account.Mixed heavy metals and various exposure ways can be designed in field experiments to observe changes of molecular biomarkers.Moreover,researches on ＂in vitro＂ markers and ＂standard＂ markers should be strengthened.Additionally,the integrated use of multiple biomarkers needs to be considered to monitor heavy metal pollution.Recently,most studies are associated with toxic effects of heavy metals while neglecting mechanism which will be one of the key issues for future research.