When you want to study ancient human and Neanderthal remains, there's a big issue of contamination with contemporary human DNA.
当你想要研究古人类和尼安德特人的遗骸，一个大问题是当代人类的 DNA 受到的污染。
2
Long-term storage and improper disposal of this material may result in dioxin release into the environment and the contamination of human and animal food supplies.
长期储存以及不当处置这种材料可能导致二恶英泄漏到环境中，导致人类和动物食物污染。
3
The MoD launched Project Cleansweep in 2007 to provide "reassurance" that residual contamination at UK sites did not pose a risk to human health or the environment.