Experts say testing needs to be done on each contaminant to determine the long-term effects on humans.
专家说需要对每种污染物进行测试，以查明对人类的长期影响。
《柯林斯英汉双解大词典》
2
High purity water systems are primarily composed of austenitic stainless steel (ss) materials due to their corrosion resistant and contaminant free properties.
考虑到铬镍不锈钢(SS)的抗腐蚀和防污染性，高纯水系统基本上都是由铬镍不锈钢材料构成。
3
Each of the membrane technologies is essentially a filtration process in which contaminant ions are filtered from solution using a membrane with very small water passages.