Smoky haze caused by widespread land-clearing fires in Indonesia eased on Friday in some southern provinces including Phuket but concerns persist in other parts of the South.
Smog in Phuket continued to breach the safe level but to a lower extent on Friday, said Pornsri Sutanaruk, director of Regional Environmental Office 15 in the southern island province.
Particulate matter reached 126 microgrammes per cubic metre of air measured on Thursday while the upper safe limit stands at 120ug/cu m. On Friday the level dropped to 121ug/cu m.
"The air quality should be gradually better in a few days," Ms Pornsri said. "Hot spots on Sumatra island are declining and the situation in the lower South including Phuket should be gradually relieved."
The haze had not affected transport in Phuket yet, she added.
Smog covered Trang province for the second consecutive day on Friday. Monpat Wungsanuwat, director of the provincial office for natural resources and the environment, said there were no health impacts yet and levels were falling.
He said he had not advised local people to stay indoors or wear face masks.
Pollution was also reported in the southern provinces of Krabi, Satun and Phangnga on Friday. Satun health officials handed out facemasks, while in Phangnga haze reduced visibility and caused eye irritation, Thai media reported.
The haze is an annual occurrence in Southeast Asia and its worst impacts are seen in Indonesia, Malaysia and Singapore.
However, this year a drought caused by El Nino is being blamed for some of the fires, in addition to blazes set by farmers to clear land for planting.
Satellite images showed hundreds of hotspots indicating fires in parts of Sumatra island and the Indonesian parts of Borneo, said Sutopo Nugroho, a spokesman for the National Disaster Management Agency In Indonesia.
"As the drought worsens, forest fires are spreading," Sutopo said.
A haze emergency was declared in Kutawaringin Timur in Central Kalimantan province on Wednesday after air pollution reached hazardous levels. The emergency is expected to last until October, a local official said.
Sutopo said the government was deploying thousands of soldiers, police and Forestry Ministry firefighting squads to extinguish the fires.
President Joko Widodo warned that legal action would be taken against those who deliberately start fires to clear land.
Smog from the Indonesian fires also enveloped Kuala Lumpur and most of the Malaysian peninsula.
Hisham Anip, a spokesman for the meteorological department, said the haze would likely last until mid-September when the monsoon season ends.
The latest data from the meteorological department showed 25 fires in Sumatra and 94 in Kalimantan.
Smog that has drifted up from Indonesia hangs over Trang on Friday (photo by Methee Muangkaew)