The studies on how humic acid (HA) influences the oxidative stress of arsenic in aquatic organism is limited. Using Danio rerio as case study, we explored the oxidative stress effects in aquatic organism after 96 h exposure to the HA and arsenic. Results revealed the co-exposure of HA and arsenite elevated the superoxide dismutase activities and downgraded the malondialdehyde. Thus, we speculate that HA may alleviate the oxidative stress induced by arsenite, which may be caused by the HA’s coating in combination with the complexation of arsenite and HA. In addition, HA acted as the reactive oxygen species scavenger, promising to eliminate the oxygen free radicals. Contrastingly, HA may impact little on the arsenate exposure. This study can help better understand oxidative stress mechanism of co-exposure of arsenic and HA in aquatic environment.

关于腐殖酸（HA）如何影响水生生物中砷氧化应激的研究非常有限。使用Danio rerio作为案例研究，我们探讨了暴露于HA和砷96小时后水生生物体内氧化应激的影响。结果表明，HA和亚砷酸盐的共同暴露提高了超氧化物歧化酶的活性，并降低了丙二醛的含量。因此，我们推测HA可以缓解由亚砷酸盐引起的氧化应激，这可能是由HA的涂层与亚砷酸盐和HA的络合作用所引起的。此外，HA起到了活性氧清除剂的作用，有望消除氧自由基。相反，HA对砷暴露的影响很小。这项研究可以帮助更好地了解在水生环境中砷和HA共同暴露的氧化应激机制。