Since a chief source of pollutants is automobile emissions, it might be expected that pollutant levels could be correlated with automobile traffic, at least to some extent.

因为污染物的主要来源是汽车的排出物，所以可以料想污染物的浓度至少在某种程度上是与汽车运输有关。

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Complete PLANTOID-type robots could be also used to monitor things like soil conditions and pollutant levels here on Earth, or they could even find use gathering environmental data on other planets.

完备PLANTOID型机器人也可以用于监视像土在地球上的条件和污染水平，或者他们甚至可以找到使用在其他行星上收集环境数据。

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Of the 13 priority pollutant metals tested for, two are found in elevated levels in passivation waste effluent waters.

在经检测的13种优先级污染金属中，发现有两种金属在钝化废液中的水平有所增加。

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The gauges are used to monitor water and pollutant levels.

WSJ: Susquehanna River commission wants gauge funding

The researchers Katherine Ensor and Loren Raun cross referenced the time and place of the cases against air pollutant levels recorded by the extensive network of air monitors throughout the Houston area.

FORBES: Researchers Prove Air Pollution Causes Heart Attacks

Two Surrey councils have said they will be working together to improve air quality as readings showed levels of a pollutant above government targets.

BBC: Air pollutants in Woking above government target levels