A milky haze has shrouded the cities for more than a month as smoke drifted from fires on Borneo and Sumatra islands.
Kuala Lumpur was the world's most polluted major city early on Wednesday, according to Swiss monitor IQAir, with an Air Quality Index (AQI) reading of 166. Singapore ranked third at 155.
The AQI converts measurements of pollutants into a single figure indicating air quality and potential health risks. Readings above 150 are class…