Wildfires blamed for drop in air quality
Northern provinces, especially Chiang Mai and Chiang Rai, were blanketed by unsafe levels of the carcinogenic PM2.5.
Suwannachai Wattanayingcharoenchai, director-general of the Health Department, said the levels of particulate matter 2.5 micrometres and less in diameter (PM2.5) exceeded 91 microgrammes per cubic metre (µg/m³) of air in 24 hours in eight northern provinces — Chiang Mai, Chiang Rai, Lamphun, Lampang, Mae Hong Son, Nan, Phayao and Phrae.
Toxic dust was also afflicting the three northeastern provinces of Bung Kan, Nakhon Phanom and Nong Khai as of late morning yesterday, he said.
The safe threshold for PM2.5 in Thailand is set at 50µg/m³ of air in 24 hours.
The PM2.5 level in tambon Wiang Pang Kham of Mae Sai district in the northernmost province of Chiang Rai reached 480µg/m³ of air in 24 hours as of 11am yesterday, Dr Suwannachai said.
The level exceeded the local safe threshold by nine times — and the World Health Organization’s standard by 32 times. The WHO sets the safe threshold for exposure over 24 hours at 37μg/m³ of air, or 15μg/m³ annually, he said.
At 10.30am IQAir, the air pollution monitoring website reported that Chiang Mai was the city with the worst air pollution in the world. The level of PM2.5 in the northern province was 33.4 times as much as the safe threshold set by the WHO.
Dr Suwannachai said he expected the air pollution to continue in the North and the Northeast, especially in border provinces, this week because of field burning in Thailand and neighbouring countries, along with stagnant air.
The high levels of PM2.5 would cause eye and skin irritation, breathing difficulties and chest pain, he said. Breathing difficulties could be acute in people with heart and respiratory tract illnesses, he added.
“Exposure to long-term and excessive PM2.5 will ultimately cause internal inflammation, damage to lung cells, cardiovascular diseases and cancer,” Dr Suwannachai said.
Trasak Srithipan, adviser to Chiang Rai Chamber of Commerce, said one of the causes of air pollution in Mae Sai was hot spots in neighbouring countries. The problem should be addressed in a regional level, he said.
Recently, a viewpoint in Chiang Rai’s Phu Chi Fa national park was destroyed by a brush fire which started in Laos, he said.
Meanwhile, the Geo-Informatics and Space Technology Development Agency reported records from Suomi NPP satellite images yesterday which showed 12,581 hotspots in Myanmar, 4,376 in Thailand, 8,535 in Laos, 744 in Cambodia, 720 in Vietnam and 31 in Malaysia on Saturday alone.
More than half of the hotspots in Thailand (3,515) are found in reserved forests, 364 in farmlands and 196 in communities.