Chiang Mai's air quality was ranked among the world's worst for a third consecutive day Wednesday as haze continued to choke the North.
The air quality index at noon Wednesday was logged at 265, the highest in the world at that moment, according to the AirVisual App, a well-known online air monitoring site. The level of PM 2.5 was recorded at 214 microgrammes per cubic metre (μg/m³).
Such a level is considered harmful to health. The World Health Organisation (WHO) caps the acceptable level of PM2.5 at 25 μg/m³, and the threshold for Thailand's Pollution Control Department (PCD) is 50 μg/m³.
Chiang Mai provincial officials were spraying water in a desperate attempt to reduce the haze. The attempt barely helped as the air quality remained at harmful levels the whole day.
The levels prompted Chiang Mai University to cancel classes for Wednesday and Thursday.
The city was among many towns in nine provinces covered by haze caused by a combination of forest fires, open burning, haze from Laos and Myanmar as well as weather conditions.
Officials were monitoring the haze situation, air quality and trying to prevent forest and farm fires. They were also seeking the cooperation of local residents not to burn garbage or agricultural waste.
