Air Pollution – AQI, PM2.5, etc.

If you talk to people who have been living in Shanghai for a few years, they will all tell you the same thing: the air quality is much better now than it used to be. Unfortunately, although this is true, it is still at a level where it remains a concern and needs to be closely monitored. Do not hesitate to protect yourself and your family when needed.

Days when the Air Quality Index is above 200 are not so common anymore, especially during summer. There are some here and there but nice days with blue sky and clean(er) air are more frequent and make you forget the bad ones. Unfortunately it is during winter that things get worse. Peaks are still not so frequent but you have longer periods with AQI around 150ish.

Most of the pollution comes from the small particulates PM2.5 and PM10. It doesn’t come so much from Shanghai itself but from factories and crop burning in other parts of China and so, depending on the direction of the wind, pollution comes and goes quickly. When the wind is not strong or when more crops are burned, like in winter, the pollution just stays…

Even when levels are high, not many people wear marks in the street, except for those riding on bikes. Unfortunately, the air is a sneaky enemy and over 4,000 people die because of bad air every day so do not underestimate it, even though you can’t necessarily see or smell it.

Protect yourself

To protect yourself, you can start with having an air quality monitor at home (for example something similar to the “AirVisual node”), get an air purifier and wear a mask outside when pollution is there. There are many brands of air purifier available on the market from good and reasonably priced ones like Xiaomi to really expensive imported ones. I personally like Xiaomi brand as it’s well priced, has good design, good quality and it’s all connected and controllable at distance from your phone. (Reminder: we are not affiliated to any brand so whatever we recommend is what we use and like). Keep in mind that buying the purifier is one thing but you also need to change the filters frequently (1 to 4 times a year depending on the models and the usage).

As for the face masks, again many brands and qualities are available but just keep in mind that some protect you better than others. You can usually see the mention N90, N95 or N99, which means that they stop 90, 95 or 99% of the PM2.5. Many people buy the masks from 3M. I think they look ugly so I cover them with a light fabric mask but they do offer a good level of protection.

What is AQI?

AQI stands for Air Quality Index. It is calculated using several pollutants like PM2.5, PM10, Carbon Monoxyde (CO)… Every country has different rules but the most widely used are the American and Chinese indexes. Be careful as the scales they are using are different. As the American one is stricter than the Chinese one, that is the one that is usually preferred.

This is the standard chart for the American AQI:

And this is the scale used by the Chinese government:


  • To monitor the outdoor air quality in real time, you can refer to the website They have many monitoring stations in the city and are pretty accurate. They are using the American classification.
  • You can also download the AirVisual app on your phone/tablet to keep a close eye on your invisible enemy…

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