By Fang Yuan

Recently, I made a trip to two major Chinese cities, Beijing and Shanghai, for about a month till late December 2016. While I was in Beijing, I was greeted with the city’s air pollution. A picture on Greenpeace China‘s webpage shows how the city looks like:

From Greepeace

I can’t say if it was because of the smog. However, I had an allergic reaction two days after I arrived in China. Moreover, I caught a flu at the end of my trip, and I even had a flu shot upon my return to the United States. All of my personal health reactions might just be a coincidence, but is the air qualilty really bad in China’s major cities? I found this data for Beijing and Shanghai from Nov. 28 to Dec. 24, 2016 coinciding with the period of my stay.

EPA scales the Air Quality Index (AQI) from 0 to 500. The higher the value, the greater the level of air pollution, and the greater the health concern. To visualize this effect, the AQI value is divided into six levels/colors. An AQI value below 100 is generally seen as satisfactory.

From EPA

On non-profit organization AQI Study‘s website, the 6-color chart clearly indicates the historical Air Quality Index (AQI) in the two cities.

Photo: Beijing AQI, Nov. 28 to Dec. 24, 2016, from AQI Study
Photo: Shanghai AQI, Nov. 28 to Dec. 24, 2016, from AQI Study

It is clear that 2/3 of the time (by hour) in Beijing is “smoggy”. Sometimes, the AQI value can spike up to a terrifying 450. On the other hand, 2/3 of the time (by hour) in Shanghai is acceptable, with an AQI value below 100.

Now, I am back in New York. How about the air quality here?

I found a website called AirNow, where you can find both real-time and historical AQI data in the United States and Canada.

Let’s look at New York’s data. The air is “good” on most days. The city had two “moderate days” on Dec. 21 and 22. Overall, the air in New York is acceptable by EPA standards.

New York AQI. Photo from

Most of the people in China are still breathing polluted air. The air in winter is usually the worst when the northern part of China burn coal for space heating. A real-time national data monitoring map shows how the air in most cities are unhealthy at 9pm on January 2, 2017.

China AQI
Real-time China AQI. Photo from

I heard that some of my Chinese friends are installing air purifiers for the entire house. It is not the regular stand-alone machine, but it is something that is integrated with the air vents. Installing a HRV or ERV (Heat Recovery Ventilator or Enthalpy Recovery Ventilator) to a building or an apartment unit is slowly becoming popular in China. Some of my Chinese friends said that they would buy the HRV/ERV machines from South Korea or Japan where people in those countries also have similar concerns on air quality.

I am not sure when China’s air quality will be improved, but I truly wish that I won’t catch a flu again the next time I am there.

Fang Yuan is originally from Shanghai and now lives in New York. She is a Certifed Passive House Consultant. Her current work focuses on building energy performance and efficient lighting project management in the Greater New York Area. She believes new technology will help people and the planet if we think about it in a systematic way and mindfully use it. This piece was curated from Fang’s blog and edited by AllChinaTech.

(Top photo from