not harmed by something (for example, dangerous or dirty substances) 未被损害的；未受污染的 uncontaminated water 未被污染的水
The equipment is sterilized to ensure that the blood remains uncontaminated. 对设备进行消毒以确保血液不受污染。 The problems were made worse by the inadequate provision of medical help and uncontaminated milk. 由于医疗救助不足和未受污染的牛奶，问题变得更加严重。