Data from air-quality monitoring app IQAir has repeatedly ranked Hanoi among the world’s 10 most polluted cities in recent days. On the afternoon of December 12, the capital topped the global list, with its Air Quality Index (AQI) reaching 272, in the purple category deemed very unhealthy.
In response, the Hanoi People's Committee Chairman Vu Dai Thang ordered urgent measures to curb air pollution, tightening dust controls at construction sites and requiring vehicle washing, water spraying and full coverage of loose construction waste during storage and transport.
However, on December 12 many construction sites were still operating without adequate dust controls, including pavement works on Nguyen Xien Street, projects in the Van Khe urban area of Ha Dong, and clearance works along Ring Road No.1.
Many small house-building sites were also operating without any dust-reduction measures.
According to Duong Hoang Tung, chairman of the Vietnam Clean Air Network, major sources of Hanoi’s air pollution include traffic, construction, recycling craft villages and the burning of straw and waste. Despite a ban, three-wheeled vehicles remain common on the city’s streets, many of them old and highly polluting.
Uncontrolled waste burning is also widespread, often taking place near residential areas and severely affecting local air quality.
By mid-2025, Hanoi had more than 7.6 million personal vehicles, including over 6.5 million motorbikes and up to 1.5 million cars. Nearly 70 per cent have been in use for more than a decade, making transport emissions one of the main contributors to the capital’s air pollution.
