HANOI — Toxic smoke billows from a burning mound of plastic bags and leaves on Le Thi Huyen’s farm in Hanoi, a city battling an alarming air pollution surge that the communist government appears in no hurry to fix.

In the last three months the Vietnamese capital has regularly topped a list of the world’s most polluted major cities, leaving its nine million residents struggling to breathe and even to see through a thick blanket of smog.

Despite a string of ambitious plans to address the crisis, few measures have been enforced and there is little monitoring of whether targets are actually achieved, analysts say.

Officially, the burning of rice straw and waste was banned in 2022 across the country — but that is news to Huyen.