free from contamination 无污染

environmental contamination 环境污染

water contamination 水污染

contamination control 污染控制；污染管制

soil contamination 土壤污染

bacterial contamination 细菌污染

oil contamination 油污

radioactive contamination 放射性污染

microbial contamination 微生物污染

food contamination 食品污染

cross contamination 交叉污染；交互粘染

lead contamination 铅污染

source of contamination 污染源

surface contamination 表面污染

mercury contamination 汞污染

particulate contamination 微粒子污染