Haze pollution was a chronic problem nationwide, long before the capital was blanketed in PM2.5 pollutants over the past few weeks.
The situation is so serious the government recently allocated more than 140 million baht to subsidise free public transport, aiming to persuade city dwellers to leave their vehicles at home, as an urgent measure to reduce fuel emissions and combustion smoke.
However, transport pollution is not the only source of the dusty air. Pollution Control Department (PCD) data shows most PM2.5 in Thailand stems from hot spots scattered across the nation.
In 2024, 68% of hot spots were reported in forest zones, 24% in agricultural zones and 8% in urban zones.
Since the beginning of this year, 10,543 hot spots have been reported.
The highest numbers were detected in rice paddy fields (3,287), followed by forest areas (3,207) and general farming zones (1,591). In the agriculture sector, rice farms were the top source of burning, followed by maize plantations and sugar cane fields.
Preeyaporn: Haze came early
PCD director-general Preeyaporn Suwanaged said traffic pollution may be the main source of PM2.5 in Bangkok, but early agricultural burning to manage agricultural waste in nearby provinces has worsened the situation.
State agencies are working to mitigate the number of hot spots, with measures that will tackle the problem at its roots. For example, the Ministry of Interior has told provincial governors to ensure there's no burning in farming zones.
The Ministry of Industry, meanwhile, has beefed up its enforcement and recently ordered the closure of a sugar manufacturing plant which had bought a large amount of burnt sugarcane beyond its legal quota.
The Ministry of Natural Resources and Environment is also taking legal action against forest burning, especially in the five provinces with the highest number of hot spots, namely Tak, Kanchanaburi, Nakhon Ratchasima, Phetchabun and Chaiyaphum.
Ms Preeyaporn said the PCD will submit a 2025-2027 draft agenda on micro-dust pollution prevention to the National Environment Board next month. She said the plan is to deal with haze pollution at its source rather than rely on lax law enforcement against wrongdoers. In Bangkok, vehicles emitting black smoke are still seen widely on the streets despite a commitment by the authorities to deal with them.
Krit: Turning point
Krit Silapachai, a spokesman for a committee studying clean air legislation, said the bill is expected to be submitted to the Lower House next month and should take effect this year.
The legislation will be a turning point for the nation's campaign to protect the environment, as the bill has drawn an unprecedented level of attention from both the public as well as policymakers.
"The bill has been drafted based on the principle that it must protect people's health. It contains active tools to provide better air quality for the public, including funding to compensate people affected by air pollution.
"However, these tools will be useless if the government fails to put them into action. The government needs to get tough in exercising the law to protect people's health and the environment," Mr Krit said.
Meanwhile, levels of PM2.5 pollution are expected to keep rising until Wednesday in Bangkok.
The Anti-Fake News Centre reports that weak air circulation and surface-level temperature inversions are expected, which will limit the dispersion of air pollutants from ground level.
As a result, PM2.5 levels are predicted to remain stable or increase, posing potential health risks lasting until Wednesday in the capital.
As such, the centre urged people to wear face masks when going out and reduce outdoor activities, as well as avoid burning activities.
People are also being urged to report black smoke emissions and open burning via the Traffy Fondue app or hotline 199.
Real-time air quality can be checked on both the AirBKK app and Facebook page, while the Bangkok Environmental Office and the Air Quality and Noise Management Division as well as the Bangkok Metropolitan Administration also issue Line alerts.
The Air Pollution Control Communication Centre has released an air quality report showing PM2.5 levels exceeding the safe threshold of 37.5 microgrammes per cubic metre (µg/m³) across multiple provinces.
PM2.5 levels recorded in 14 areas in the North ranged from 11.3–63.2 µg/m³. The Northeast saw 33.1–74.5 µg/m³, while between 28.7 and 79.5 µg/m³ were found in the Central region and West. The figure was 30.8–69.4 µg/m³ in the east, 20.0–40.6 µg/m³ in one South area and 38.8–74.0 µg/m³ in Bangkok and adjacent provinces.