In the past two years, the WHO's database of cities monitoring air pollution has nearly doubled - now covering 3000 cities in 103 countries.

在以往两年里，世卫组织的城镇空气污染监督数据库扩大了将近一倍，目前已覆盖103个国家的3000个城镇。

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WHO will remain in contact with experts monitoring air quality in the affected region, and advises people to follow the latest guidance from their local health officials.

卫生组织将继续与在受影响区域检测空气质量的专家保持联系。建议人们遵守当地卫生组织出台的最新指导。

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This sensor is ideal for collecting temperature data for energy density calculations and monitoring air temperature at remote sites.

在测风塔上安装温度传感器的目的是为了计算风能密度，以及监测风场的环境温度。

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Marathon organisers are also monitoring the air pollution levels in London for any change caused by the volcanic eruption in Iceland.

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Environmental health officers from Blaenau Gwent council told the meeting that monitoring suggested air pollution was not at a critical level, but this would continue.

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Jones added sensors that, by monitoring the air temperature above and below the heli ten times a second, can keep the chopper at a fixed altitude with more accuracy than a human on the ground can.

FORBES: Eye in the Sky