As a result, to control water eutrophication of these lakes, it is not most urgent to control nitrogen deposition but to control the other sources of nitrogen pollution mentioned above.

因此，对控制这些湖泊的水质富营养化而言，控制氮沉降并不是目前最紧迫的任务，而其它人为污染源的控制才是最急需的。

youdao

The major sources of water pollution can be classified as municipal, industrial, and agricultural.

水污染主要可分为城市水污染、工业水污染和农业水污染。

youdao

But lignin becomes one of the main pollution sources, coming from waste water in the paper-making factory.

它是造纸厂排出的废液中的主要成分，是主要的水污染源之一。

youdao

Northumbrian Water said it was confident the steps would improve the bathing water, but added there were sources of pollution beyond its control.

BBC: Northumbrian Water to put ?6m into Saltburn water works

The contribution of diffuse sources of pollution to bathing water failures, both rural and urban, is being investigated.

BBC: Beaches 'need to improve'

If these needed protein sources were to come primarily from livestock there is the very real potential for catastrophic pollution of water and land, not to mention the exponential increase in carbon emissions.

CNN: Oceans: Environmental victim or savior?