Because of such leaks, the air in an average home was replaced by fresh outdoor air about once an hour.

存在这样的裂缝，一个普通房屋里大约每小时会置换一次新鲜的室外空气。

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It has been trying out monitoring stations that are intended to yield minute-to-minute maps of outdoor air pollution.

它一直在尝试建立监测站，以生成精确至分钟的室外空气污染分布图。

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Around 9 in 10 people in low-and middle-income countries live in places where they regularly experience dangerous levels of outdoor air pollution.

在低收入及中等收入国家，大约十分之九的人生活在室外空气污染经常达到危险程度的地方。

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They found that indoor air pollution causes pulmonary diseases that kill an estimated Outdoor air pollution accounts for another 470 thousand deaths.

VOA: standard.2010.04.07

Carrier's gadget instead uses the heat in outdoor air as the energy source.

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Indoor air can be up to 10 times as polluted as outdoor air, triggering health problems such as asthma.

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Outdoor air pollution is at its lowest level in 30 years.

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