pollution threat

基本解释

The worst pollution threat is concentrated in and near large cities.
最严重的污染威胁集中在大城市内或其附近。
However, substantial amounts of urban garbage are dumped and buried at the surface, which constitutes a serious pollution threat to the groundwater source.
但其地表堆埋了大量的城市垃圾，对地下水源构成严重的污染威胁。
Pollution poses a threat to the continued existence of this species.
污染对这一物种的继续生存造成了威胁。

Yet, while our livelihoods are inseparable from the health of these natural systems, our oceans are under threat from pollution, coastal development, overfishing, and climate change.
WHITEHOUSE: Presidential Proclamation -- National Oceans Month, 2012
This does not surprise environmentalists, who have long argued that any policy of pollution-reduction that does not include a threat of punishment for non-compliance is useless.
ECONOMIST: The Lone Smog State