Results from PAM air quality measurement method at over 40 locations in Hanoi at 8 am on September 15 showed that the air quality index was from 150 to 170. An air quality index over 100 is considered bad and people with respiratory and heart diseases are advised to stay home. If the index increased to over 150, all citizens are affected.

PM2.5 Particles pollution is the most severe problem. PM2.5 can cause cancer and genetic diseases but normal masks can't prevent such particles from entering the body.

Some photos of Hanoi's streets on September 15:

Smoggy Le Thanh Tong Street

Truong Chinh-Dai La-Nga Tu So intersections often have congestion, constructions and severe pollution

Trapped dust on Thang Long Avenue

Travellers must wear masks and coats when going outside

DTinews/TTXVN