Post-retreat, AirVisual affirms "Hanoi is not the most polluted city"

The AirVisual app is no longer available in Vietnam

Louis Watt, spokesman of IQAir AirVisual, said that the application was temporarily made unavailable in Vietnam due to the record number of one-star ratings it received from users in the country. Moreover, the company's official website posted an article reaffirming “Hanoi is not the most polluted city in the world.”

Specifically, IQAir AirVisual on October 6 posted an article titled "Concern in Vietnam at Hanoi topping AirVisual's ranking" aiming to explain what it called a "misunderstanding".

We have noticed some concern in Vietnam that Hanoi has been at no. 1 on AirVisual’s “major city ranking” at certain times over recent days.

We would like people to be aware that this does not mean that Hanoi is the world’s no. 1 polluted city. The “major city ranking” currently consists of around 90 major global cities.

At any one time, a city can top the live ranking, as happened with London and even San Francisco last year.

We also publish a separate annual world ranking in partnership with Greenpeace. The report published in March showed that Hanoi was not in the world’s top 200 most polluted cities in 2018.

On our platform, we are transparent about where we get our data from and how we publish it. For calculating Hanoi air quality, AirVisual uses data from the governmental Hanoi Environmental Monitoring Portal and from the US embassy to report real-time air pollution levels. In the AirVisual app and on the website, we always publish the source of the data to be fully transparent to our users. If you are unsure about the data, please refer to the source and contact us to report a problem.

We believe that awareness of pollution levels is what leads to change. That’s what happened in Beijing: when people realized how serious air pollution was, they pushed the government to implement stronger environmental policies. As a result, Beijing pollution has dropped dramatically.

In short, the pollution indexes offered by AirVisual are only valid for the exact moment of measurement and do not represent the air quality in the whole city.

Air pollution has become a hot issue over the past time, especially after the AirVisual application listed Hanoi as the city with the worst air quality. The information has caused a huge stir, causing people living in the city to worry about their health, while some accused the application of being unreliable.