Ji Xiuling, Hu Weixuan, Cheng Jinping, Yuan Tao, Xu Fang, Qu Liya, Wang Wenhua
School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 201240, People's Republic of China.
Ecotoxicol Environ Saf. 2006 Jun;64(2):171-7. doi: 10.1016/j.ecoenv.2005.03.009.
The Wanshan mercury mine is the largest mercury deposit in Guizhou Province, China. Few attempts have been made to study the toxic effects of mercury on biota in this mining area. This study was the first to investigate the oxidative stress on domestic ducks (Shaoxing duck) chronically exposed to mercury in the Wanshan mining area. Chemical analyses revealed higher concentrations of both, mercury and selenium in samples from the Wanshan area. Total mercury and selenium concentrations in duck tissues varied from 0.073 to 4.465 mg/kg and from 1.073 to 6.35 mg/kg, respectively. Analysis of covariance revealed that there were significant effects of zone on accumulation of mercury and selenium in all duck tissues (P<0.01). Moreover, analysis of covariance indicated that mercury content significantly affected the accumulation of selenium in duck muscle, brain, and liver (P<0.01). Mercury and selenium were also highly correlated in Wanshan duck liver, muscle, brain, and lung. The statistical analysis suggested that selenium might be an interactive factor in mercury toxicity. As for the biochemical analyses, it was observed that selenium-dependent glutathione peroxidase and superoxide dismutase activities and glutathione (GSH) content were significantly increased in the livers and brains of Wanshan ducks (P<0.01, 0.05). However, no significant changes were observed in malondialdehyde content (P>0.05). Although the results indicated that adaptive responses of the redox-defense system are associated with the increased enzyme activities and GSH content, the most likely explanation is that selenium plays a critical role. Therefore, the effects of the interaction environmentally occurring selenium and mercury on public health in the Wanshan area should be examined in further studies.
万山汞矿是中国贵州省最大的汞矿床。此前很少有人尝试研究该矿区汞对生物群的毒性影响。本研究首次调查了长期暴露于万山矿区汞环境中的家鸭（绍兴鸭）的氧化应激情况。化学分析表明，万山地区样本中的汞和硒浓度均较高。鸭组织中的总汞和硒浓度分别在0.073至4.465毫克/千克和1.073至6.35毫克/千克之间。协方差分析显示，区域对所有鸭组织中汞和硒的积累有显著影响（P<0.01）。此外，协方差分析表明，汞含量对鸭肌肉、大脑和肝脏中硒的积累有显著影响（P<0.01）。在万山鸭的肝脏、肌肉、大脑和肺中，汞和硒也高度相关。统计分析表明，硒可能是汞毒性的一个交互因素。至于生化分析，观察到万山鸭肝脏和大脑中硒依赖性谷胱甘肽过氧化物酶和超氧化物歧化酶活性以及谷胱甘肽（GSH）含量显著增加（P<0.01，0.05）。然而，丙二醛含量未观察到显著变化（P>0.05）。虽然结果表明氧化还原防御系统的适应性反应与酶活性和GSH含量的增加有关，但最可能的解释是硒起了关键作用。因此，环境中硒和汞的相互作用对万山地区公众健康的影响应在进一步研究中进行考察。
