Thailand — The Pollution Control Department (PCD) has found that the amount of small dust particles – or those in the size of PM10 – is already below the dangerous level in most northern provinces after the heavy rain.
Before the rain, the northern region had faced smog-related health threats for weeks.
Yesterday, only Mae Hong Son and Chiang Rai struggled with dangerously high amounts of PM10 particles.
For people to remain healthy, the amount of PM10 particles should not soar above 120 micrograms per cubic metre of air. In Mae Hong Son, levels stood at 359 micrograms per cubic metre of air. In Chiang Rai, they were recorded at 158 micrograms.
Natural Resources and Environment Ministry permanent secretary Chote Trachu, however, said that at some points the amount of small dust particles in the air above Chiang Rai’s Mae Sae district soared as high as 438 micrograms per cubic metre of air. “It’s harmful to people’s health,” he said.
He said the smog in this border zone had worsened partly because people in neighbouring Burma had continued to light fires to clear land for farming.
Chote said there were more than 900 fire hotspots in Burma.
“We are seeking co-operation in Burma because the smoke there is blowing over here,” he said.
Chiang Rai disaster prevention and mitigation chief Prajon Prajsakul said, “The problem stems partly from a high-pressure ridge, which blocks the smoke from soaring higher and higher.”
Chiang Rai Governor Thanin Supasaen ordered that water be sprayed into the air to ease the smog. Masks were also handed out to locals so they could protect themselves.
However, in other areas the rain has proved effective in eradicating the smog problem. For example, the amount of PM10 particles in Lampang significantly dropped from 177 micrograms per cubic metre of air to just 68 micrograms. Yesterday, the PCD reported the PM10 in Chiang Mai’s Muang district stood at just 103 micrograms.
Figures recorded in Nan, Lamphun, Phrae and Phayao stood at 74.58 micrograms, 118.88 micrograms, 54.92 micrograms, and 102.57 micrograms.