" It is time to take action , " says yuan daoxian , a hydrogeologist at the institute of karst geology in guilin , china .

来自中国桂林喀斯特地质研究所的水文学家袁道县说，现在是时候采取行动了。

Other lab-based studies have suggested that sediments in deeper aquifers tend to keep arsenic out of the water , says william burgess , a hydrogeologist at the department of earth sciences at university college london .

其他一些以实验为基础的研究认为深层蓄水层中的沉积物可以将砷隔离在水之外，威廉.博格斯说，他是伦敦大学学院地球科学部门的一位水文地质学家。