I decided just to google Beijing air quality and both results came back... Not so good.

"Dangerous Any exposure to the air, even for a few minutes, can lead to serious health effects on everybody. Avoid outdoor activities." https://www.accuweather.com/en/cn/beijing/101924/air-quality...

"Very Unhealthy Health warnings of emergency conditions. The entire population is more likely to be affected." https://aqicn.org/city/beijing/

So not sure I fully believe that.