The Bangkok Metropolitan Administration (BMA) insisted there was no need to shut its 437 schools in the city, while hazardous PM2.5 ultra-fine dust particles exceeded the safe level in 11 locations in Bangkok and the surrounding provinces on Thursday.
PM2.5 dust levels measured at 7am on Thursday ranged from 15 to 75 microgramme per cubic metre, according to a report issued by the Pollution Control Department.
The three highest levels on Thursday were measured on Ma Charoen Road in Nong Khaem district (75 µg/m3), Rim Khlong Thawi Wattana Road in Thawi Wattana district (70 µg/m3), and in tambon Maha Chai in Muang district of Samut Sakhon (70 µg/m3), the department said.
Average levels of PM2.5 in other parts of the country aside from Bangkok and its surrounding provinces were, on the other hand, rated as "very good", ranging from 3 µg/m3 to 37 µg/m3, the department said.
Kriangkrai Chongcharoen, director of the BMA's Department of Education, insisted on Thursday that shutting down schools under the department's jurisdiction wasn't an option at the moment as these schools were still capable of mitigating the impact of high PM2.5 dust levels on the health of students and teachers using a range of measures.
Among measures being implemented at these schools were increasing air ventilation by installing more electric fans and getting very young students into the schools' rooms heavily shielded against the ultra-fine dust particles, he said. These schools now altogether have 1,841 such rooms for use during serious dust situations, he said.
The decision whether to shut any particular school lies with school administrators who may take into consideration the specific PM2.5 situation in their areas when judging if their schools need to suspend classes and for how long, he said. These schools are being advised to bring in place air purifiers and PM2.5 measuring devices as a permanent defence against the dust; but not all of them could find sufficient funds to purchase these devices.
Prime Minister Prayut Chan-o-cha, meanwhile, encouraged members of the public in PM2.5-affected areas to keep wearing face masks to lessen the impact of the air pollution on their health.
The government was monitoring the dust situation and weighing up the advantages of stiff measures being proposed for use to handle the dust situation in Bangkok, which include prohibiting certain types of cars in certain zones of the city and getting people to work from home and students to study online temporarily.
Agriculture Minister Chalermchai Sri-on, meanwhile, said he had ordered artificial rain-making operations in an attempt to wash out as much of the dust as possible in the air.
The ministry is attempting to prohibit biomass burning especially in the North and Central Plains that previously experienced problems, the minister said.