题主是觉得taint本身已经带有“污染”的意思，所以pollution显得多余吗？

是否可以这样假设：干净的water or air也不一定能够taint the land。

而且这里的pollution是否可以取“污染物”义项（即“2substances that make air, water, soil etc dangerously dirty污染物”），而不是这个义项“the process of making air, water, soil etc dangerously dirty and not suitable for people to use, or the state of being dangerously dirty污染”。