Haze engulfed Hà Nội on Thursday. Photo taken on Thăng Long Avenue. — VNA/VNS Photo

HÀ NỘI — Hà Nội was named as the most polluted city in the world on Thursday, with HCM City not far behind.

Figures released by the air quality monitor app AirVisual put Việt Nam’s capital city at the top of the list followed by Jakarta in Indonesia and HCM City, respectively taking the second and third places. 

On Thursday, Hà Nội’s air quality index topped the 200 mark, which is considered hazardous.

Although the air conditions slightly improved, Hà Nội’s recorded air quality is still among the worst places in the world.  

The monitor constantly updates and changes depending on the Air Quality Index. Change of seasons also reduces air quality.

According to the air monitoring system of Hà Nội Department of Natural Resources and Environment, the city air quality has remained at “unhealthy” levels in recent days, mostly due to dust pollution.

Bad weather in the capital and fog made it difficult for the dust to be diluted or blown away.

At the same time, low wind speeds reduce air convection and trapping dust near the surface all contributed to the declining quality of the air in Hà Nội.

The rapid urbanisation in Hà Nội was the major cause besides the rising number of vehicles and traffic congestion, said Mai Trọng Thái, head of Hà Nội Environment Protection Department.

According to Thái, AirVisual uses data provided by US Embassy’s monitoring station located near the Láng Hạ-Đê La Thành intersection where there are many passing vehicles and construction sites, which mean that the measurement is not indicative of the entire city.

Air quality at different areas around the city can be checked at www.moitruongthudo.vn by Hà Nội Air Quality Monitoring Network, www.pamair.org by PAM Air Map of air quality and www.fairnet.vn FAirNet Map of air quality. — VNS

The top ten most polluted cities showed on AirVisual's at 10am on Thursday were: 

Hà Nội – Việt Nam at 187

HCM City – Việt Nam at 172

Jakarta – Indonesia at 167

Tashkent – Uzbekistan at 161

Hangzhou – China at 158

Wuhan – China at 157

Lahore – Pakistan at 155

Guangzhou – China at 154

Dhaka – Bangladesh at 148

Kabul – Afghanistan at 141