A recent study by the U.N. children’s agency UNICEF found that more than 500 million children in East Asia and Pacific countries breathe unhealthy air. The pollution is linked to the deaths of 100 children under age 5 every day. June Kunugi, UNICEF’s Regional Director for East Asia, said the polluted air limits growth, harms lungs and affects thinking abilities.

联合国儿童机构联合国儿童基金会最近的一项研究发现，东亚和太平洋国家有超过5亿儿童呼吸不健康的空气。 污染与每天5岁以下100名儿童的死亡有关。 联合国儿童基金会东亚地区主任六月库吉（June Kunugi）表示，污染的空气限制增长，伤害肺部并影响思维能力。

“Every breath matters, but for too many children every breath can bring harm,” she said.

她说：“每一次呼吸都很重要，但是对于太多的孩子来说，每个呼吸都会造成伤害。”

Over 6,000 cities in 117 countries now record and follow air quality levels. Many mobile apps include air quality information as well. But it can be difficult to know how bad the air is by looking at these numbers.

现在，117个国家 /地区有6,000多个城市记录并遵循空气质量水平。 许多移动应用程序还包括空气质量信息。 但是，通过查看这些数字，很难知道空气有多糟。

To help people better understand air quality levels, many countries have established an air quality index, or AQI. Larger numbers on this index mean worse air.

为了帮助人们更好地了解空气质量水平，许多国家已经建立了空气质量指数或AQI。 该指数上的数量较大，意味着空气较差。

Different countries have different air quality standards. For example, India’s daily PM 2.5 limit is more than 1.5 times higher than in Thailand and 4 times higher than WHO standards.

不同国家的空气质量标准不同。 例如，印度的每日PM 2.5限制比泰国高1.5倍，比WHON标准高4倍。

For individuals, experts say the goal should be to limit exposure when air quality is bad, by staying indoors or wearing a mask. This is not always possible, though. Danny Djarum is with the World Resources Institute. He told the AP there are many people who live or work outside and “can’t really afford” to stay indoors.

对于个人而言，专家说，目标应该是在空气质量不好，呆在室内或戴口罩时限制曝光。 但是，这并不总是可能。 丹尼·贾鲁姆（Danny Djarum）与世界资源研究所（World Resources Institute）在一起。 他告诉美联社，有很多人在外面生活或工作，并且“真的负担不起”留在室内。

People also need to watch indoor air pollution that can be caused by common household activities like cooking or burning incense.

人们还需要观看室内空气污染，这可能是由烹饪或燃烧香（例如烹饪或燃烧香）引起的。

While air purifiers can help reduce indoor air pollution, experts say they do have limitations. The devices work by pulling air from a room and then pushing it through a filter that traps pollutants. The filtered air is then sent back into the room.

虽然空气净化器可以帮助减少室内空气污染，但专家说它们确实有局限性。 设备通过从房间拉出空气，然后通过捕获污染物的过滤器将其推送出来。 然后将过滤的空气发送回房间。

Air purifiers work best when used in small spaces and when people are nearby. This is because they can only clean a certain amount of air, said Rajasekhar Balasubramanian of the National University of Singapore. He added, “If we have a tiny air purifier in a large room, it won’t be effective.”

空气净化器在小空间和附近的人们时使用最佳。 新加坡国立大学的Rajasekhar Balasubramanian说，这是因为他们只能清理一定数量的空气。 他补充说：“如果我们在一个大房间里有一个很小的空气净化器，那将不会有效。”