1、The toxicity of the chemicals in the water poses a serious threat to marine life.
这些化学物质在水中的毒性对海洋生物构成了严重威胁。
2、Exposure to high levels of air pollution can lead to respiratory problems due to the toxicity of the pollutants.
由于污染物的毒性，长时间暴露在高浓度的空气污染中可能会导致呼吸系统问题。