contaminate/contamination

contaminate /kənˈtæmineit/ vt. 弄脏，污染： Flies contaminate food. 苍蝇污染食物。The oil spills at sea contaminate the sea. 海上溢出的原油污染海洋。

contamination n.污染，弄脏，污染物：［考句］Now a paper in Science argues that organic chemicals in the rock come mostly from contamination on earth rather than bacteria on Mars. ‘科学’杂志上有篇文章认为岩石中的有机化合物主要源自于地球上的的污染，而不是火星上的细菌。