1. But carbon dioxide is not a contaminant—it is the inevitable by-product of carbon in the coal reacting with oxygen in the air. 但是，二氧化碳并不是污染物质——它是煤炭和氧气在空气中反应后产生的不可避免的副产品。
2. "Plastics are a contaminant that goes beyond the visual, " says Bill Henry of the Long Marine Laboratory at the University of California, Santa Cruz. 加州大学圣克鲁兹分校长期海洋实验室的比尔亨利说：“塑胶是一种污染物，其危害性超出人们预料。”
3. The detection limit for each analytical method should be sufficiently sensitive to detect the established acceptable level of the residue or contaminant. 每一个分析方法的检测限度年应有充分的灵敏度以能检测到建立的认可水平上的残留或污染。
