For the fourth day in a row, the red flag has been flown in front of the Baan Phra Non in Don Kaew subdistrict of Mae Rim. Signaling air pollution at hazardous levels, the flag is a warning for its 206 students and 15 teachers to take refuge in the school’s three Safety Zones – sealed rooms with air purifiers. “Our area suffers more than many others from air pollution,” said Narong