THREE PROVINCES in the North, including Chiang Mai, faced PM2.5 levels higher than the standard safe levels for health.
Officials attempted to reach the origins of the smog, including forest fires and burn-offs in order to tackle the haze.
In Chiang Mai, the high concentration of PM 2.5 – dust particles with diameter less that 2.5 microns per square metre – that can affect the human respiratory system reached 63 microns per square metre, prompting Chiang Mai residents to adjust their daily lifestyles, including switching to indoor exercises.
Overall visibility was low and people said they were hardly able to view the usually prominent Doi Suthep Stupa on Doi Suthep from a distance.
People suffering from allergy, like Lamduan Inthawong,42, were worried that their health might be affected if the situation worsened, but she hoped it would improve in the next few days.
In Phayao province, the situation was similar with the concentration of PM 2.5 recording 78 microns per sqm. Officials made attempts to draw water from Kwan Phayao Lake and spray it in the air to improve visibility.
In Mae Hong Son province, which has faced smog for three consecutive days, people struggled with low visibility. The PM 2.5 level measured 64 microns per sqm.
Officials found 10 small hot spots in Mae Hong Son downtown, while two major ones occurred on the high mountains close to the border. The officials failed in their efforts to reach the spots due to the rugged terrain.
Meanwhile, the Northeastern Royal Rainmaking Operation Centre is extending the rainmaking operation period, as part efforts to reduce air pollution, until the end of February.
The director of the Northeastern Royal Rainmaking Operation Centre, Wassana Wongrat, said the Department of Royal Rainmaking and Agricultural Aviation (DRRAA) had set up a rapid deployment unit to conduct royal rainmaking operations to improve air quality in Khon Kaen province last week.
The air quality in and around Khon Kaen and much of the northeastern region has been poor for the past month, mostly due to the plantation burn-off.
The centre has been closely monitoring air quality in the northeastern province and found that the conditions would be suitable for rainmaking operations from yesterday until tomorrow.
The DRRAA director-general, Surasee Kitimonthon, has ordered the rain-making unit in Khon Kaen to extend the royal rainmaking operations period up to the end of the month.