Delhi's 24-hour air quality index measures the concentration of harmful pollutants.

德里的24小时空气质量指数衡量有害污染物的浓度。

On Wednesday, in upstate New York, we saw the air quality index readings of 460.

周三，在纽约州北部，我们看到空气质量指数读数为 460。

According to the World Health Organization, air quality index between zero and 50 is considered good.

根据世界卫生组织，空气质量指数介于0和50属于较好情况。

Bottom line - he tells his patients to limit outdoor activity when air quality index hits a hundred.

底线是，当空气质量指数达到100时，他提醒病人要限制户外活动。

On Tuesday, the air quality index came close to the level of 400 for tiny particulate matter.

周二，该市的空气质量指数（每立方米空气中微小颗粒物含量）接近400。

But Dr. Kalhan says when the air quality index is at 200, it's the equivalent of smoking about a half pack of cigarettes.

但卡尔汉医生表示，当空气质量指数为200时，肺部相当于抽了半包烟。

Now, Indian Prime Minister Narendra Modi is launching a national air quality index to monitor pollution levels in 10 of the country's major cities.

现在，印度总理纳伦德拉·莫迪 (Narendra Modi) 正在推出一项全国空气质量指数， 以监测该国 10 个主要城市的污染水平。

Sure. Well, in the Chicago area, the air quality index is hovering above 200, which is very unhealthy. In Washington, D.C., right now, it's about 165 - also unhealthy.

是的。嗯，在芝加哥地区，空气质量指数徘徊在200以上，非常不健康。在华盛顿特区，目前的指数为165——同样不健康。

So it's important, and there are federal rules that require employers to provide masks once the air quality index hits certain levels, but those rules are really hard to enforce.

所以这很重要，联邦规定要求雇主在空气质量指数达到一定浓度时提供口罩，但这些规定很难执行。

Many experts that I've spoken with have really encouraged people to make sure that they're checking the air quality index reports, knowing what that means, you know, use that to best protect themselves.

我采访过的许多专家都鼓励人们查看空气质量指数报告，了解这些指数的意义，并利用它来最好地保护自己。

Mr. Modi launched the air quality index at a two-day conference that included the environment and forest ministers from all Indian states. Officials at the conference are considering measures to strengthen environmental laws.

莫迪先生在为期两天的会议上发布了空气质量指数，与会者包括来自印度各邦的环境和森林部长。与会官员正在考虑加强环境法的措施。