This claim was refuted by the Division of Environmental Protection under Hanoi Department of Natural Resources and Environment, saying the result was recorded at one location and therefore cannot represent the whole city’s AQI.
Air Visual’s result was taken at the monitoring station near the US Embassy in Hanoi which is surrounded by large-scale construction sites, explained the Environmental Protection Division.
Meanwhile, Hanoi’s AQI on September 26 was reportedly 157, according to the city’s automated air monitoring result announced on its web portal.
Hanoi Department of Natural Resources and Environment’s monitoring system also showed a low pollution level these days, suggesting that the smog level only go up during certain times of the day.
On the other hand, unfavorable weather had caused smog to form above the city for days. Specifically, the lack of rainfall and wind led to poor air dispersion, causing dust to be held beneath the cloud surface and lower the city’s overall air quality, stated the division.
