Halem Chemarikan, director of the office, said Hat Yai was hardest hit yesterday with particulate matter in the air measured at 108 micrograms per cubic metre, down from 136 at 8pm on Saturday, and below the 120 micrograms safety limit.
Surat Thani, Phuket, Narathiwat, Yala and Satun were also covered with haze, but at an average level of 80 micrograms.
Halem said the haze situation was being closely |monitored by his office.
Children and the elderly with respiratory problems should wear a mask and refrain from going outdoors, he said.
Yala public health chief Dr Utissak Haritrattanakul said the haze could cause eye irritation, nausea, vomiting, tightness in the chest and difficulty breathing. “Please prepare medicines and necessary equipment if you have any underlying diseases. Also visit doctors if they develop any symptom,” he said.