His Majesty the King has expressed concern over the haze in the North and suggested that volunteers who are enlisted under the royally initiated "Jit-Arsa" project to help tackle the problem.
The King's concern was delivered by the Ministry of Natural Resources and Environment.
Gen Siva Paramoratat, commander of the Jit-Arsa 904 troop, and Theerapat Prayurasidhi, special inspector at the PM's Office and coordinator of the royal Jit-Arsa project, all attended the meeting with the Ministry of Natural Resources and Environment on Sunday to discuss ways of easing the smog in the northern provinces.
"The King said the problem has escalated and is now beyond the provincial authorities' power to deal with," according to Sophon Thongdee, a spokesperson for the ministry.
"The government should take action, including on behalf of all the volunteers so they can join hands to deal with the problem, ministry spokesman Sophon Thongdee said.
Air pollution in the North reached critical levels last month, largely because of large-scale forest fires and open burning -- both locally and from Laos and Myanmar.
The level of PM2.5 microscopic dust particles in cities like Chiang Mai, Chiang Rai and Mae Hong Son soared to 300-500 microgrammes per cubic metre (µg/m³).
However, the situation improved on Monday. The highest level of PM2.5, an invisible dust that can lodge deep inside the lungs and possibly causes migraines and cardiovascular diseases, was measured at 216 µg/m³ at Muang Mae Hong Son district in Mae Hong Son.
Even so, the dust particle level has far exceeded Thailand's safety level of 50 µg/m³. The standard handed down by the World Health Organization (WHO) is 25 µg/m³.
The situation is so severe that Prime Minister Prayut Chan-o-cha has felt the need to skip his regular weekly meeting today and fly to Chiang Mai.
On the issue of trans-boundary haze, Gen Prayut said the Thai government has discussed the matter with senior officials in both neighbouring Laos and Myanmar.
He said the regime would pursue this agenda at a regional meeting to be held at an Asean venue.
On a national level, Gen Prayut said local authorities already have a plan in place to reduce the source of the haze, one they launched in 2016.
"We've done what we need to do but the forest fires are still raging and intensifying ... which means our law enforcement efforts are failing," he told the media on Monday.
"Arresting wrongdoers, and using the law to deter people from setting fires in forests, are challenges we still need to overcome," he added.
The Royal Thai Police arrested 230 people for starting fires in northern forestland last year, up 15% from 2017.
Deputy police chief Pol Gen Srivara Ransibrahmanakul said all the culprits did this to clear forests for land to cultivate.
The Royal Thai Air Force sent two BT-67 planes on Monday to spray water over Chiang Mai, starting with tourist landmarks and popular sporting areas.