Two schools in Bangkok are closing for three days in a bid to protect their young students from the PM2.5 haze, minuscule particulate matter that can enter lung tissue and blood vessels.
Roong Aroon School and Chulalongkorn University Demonstration Elementary School, usually known simply as Satit Chula, were among the first in Bangkok to take matters into their own hands and shutter elementary classes as of Wednesday.
Roong Aroon School posted a message on its official Facebook account to explain its concerns about PM2.5 on students' health.
Principal Sunisa Chuencharoensook said it would be safer for them to stay at home as it is difficult to force students of such a young age to wear face masks.
"Their faces are too small and they become overly stressed," she told the media.
Smaller children are more vulnerable to PM2.5 due to the size and under-developed nature of their lungs and trachea.
The school is near Rama II Road in the Thon Buri area. The road, known for its constant heavy traffic, is a gateway to the southern provinces and consistently suffers high levels of PM2.5.
Tinnakorn Buapoon, the principal of Chulalongkorn University Demonstration Elementary School, told the media the school had to close for three days after a number of young students recently developed fevers.
The number infected has since risen to 130. District health office instructed the school to cancel classes to prevent more cases. The school is near Rama IV Road and the Sam Yan area, another highly polluted area.
Praharuthai Convent, which lies next to Klong Toey Intersection off Rama IV Road, has not closed but has made scheduling changes despite local levels of PM2.5 hitting 64 microgrammes per cubic metre (µg/m³), making this one of the worst-hit parts of Bangkok.
Health agencies say anything up to 50 µg/m³ is acceptable but higher levels pose risks to those with cardiovascular and respiratory problems.
Somchitr Sapapparapai, an executive at Praharuthai Convent, said all physical education classes and outdoor activities had been put on hold for the past week.
Meanwhile, the Pollution Control Department (PCD) reported that the Air Quality Index improved slightly Wednesday thanks to increased air circulation, which helped to dissipate the dust particles at a higher altitude.
However, the PCD expected a high-pressure cell from China would arrive next week, ramping levels back up from this weekend until early next week.
Gen Surasak Karnjanarat, the environmental minister, was optimistic the government would find a way to tackle the problem in Bangkok and outlying areas.
He claimed spraying water into the air had helped. Authorities next plan to use drones.