According to data from IQAir.com, at 2 PM today, Hanoi’s AQI measured 174. The city with the worst air quality in the world at that time was Kolkata, India.

The Northern Environmental Monitoring Center, under the Ministry of Natural Resources and Environment, also reported Hanoi’s AQI at hazardous levels  -  the highest recorded in the region today.

The center warned that air quality would remain "very unhealthy" over the next 48 hours across Hanoi and nearby provinces including Hung Yen, Hai Phong, and Ninh Binh.

In response to worsening pollution, the Department of Preventive Medicine under the Ministry of Health issued a public advisory urging citizens to wear certified masks when going outside.

It recommended smokers reduce or quit smoking altogether and avoid spreading tobacco smoke in shared living spaces.

People sensitive to air pollutants are advised to avoid sources of emissions. If experiencing symptoms like coughing, difficulty breathing, or chest pain under poor air conditions, they should seek immediate medical attention.

In the morning of December 9, Hanoi's AQI hit a staggering 283  -  categorized as “very unhealthy.”

A dense layer of smog enveloped the city, reducing visibility so severely that even nearby skyscrapers seemed to vanish in the haze.

Duc Hoang