Residents of Thailand face a grim reality as they enter 2025, with skies shrouded by fine dust posing a growing risk to their health.
PM2.5, or dust particles measuring less than 2.5 micrometres in diameter, can be inhaled deep into the lungs, passing into the bloodstream and lodging in other organs. Researchers have linked long-term PM2.5 exposure to premature death, with heightened risk for people with chronic heart or lung disease.
PM2.5 pollution is also associated with lung and growth problems in children.
The Disease Control Department reports that between October 1, 2023 and December 31, 2024, more than one million people in Thailand suffered health issues linked to PM2.5 pollution.
Among those issues were eye and skin irritation, chronic obstructive pulmonary disease, asthma and even heart attacks.
New year, old story
Environmental academic Sonthi Kochawat recently expressed dismay over the ongoing PM2.5 problem, complaining of little progress despite the Clean Air Bill passing its first reading in Parliament early last year.
“The country’s smog crisis remains unchanged,” he stated, blaming the crisis on the widespread burning of sugarcane fields, factory emissions, and exhaust smoke from vehicles. Authorities have done little to curb these sources despite the ongoing threat to public health and lives from PM2.5 smog" Sonthi said.
The Industry Ministry has announced a ban on sugar factories purchasing cane harvested by burning during the 2023-2024 farming season, yet 29.74% of the sugarcane bought by factories was charred.
Sonthi claims sugarcane factories have already bought about 4 million tonnes of burnt sugarcane this year, which means some 400,000 rai of farmland was burned, releasing around 1,000 tonnes of PM2.5 dust.
Unsafe levels persist
Four levels of air quality are calculated based on the amount of PM2.5 dust particles in a cubic metre of air.
The Green (acceptable) level is 15.1 to 25 micrograms per cubic metre (μg/m3). Yellow (moderate risk) is 25.1 to 37.5μg/m3, while Orange (unhealthy for sensitive groups) is 37.6 to 75, and Red (unhealthy for all groups) is 75 and above.
However, the World Health Organisation sets the safe level of PM2.5 at 5 μg/m3.
On Tuesday (January 14), all 50 districts of Bangkok were marked Orange, while several areas across Thailand were Red.
Pollution in the capital is blamed mainly on heavy road traffic, industrial operations and agricultural fires in the Central region and Northeast. Smog also blows across the border from neighbouring countries like Cambodia.
However, the biggest source of fine dust pollution in Thailand’s North, Northeast and Central regions is believed to be burning at harvest time on farmland.
An estimated 38 million Thais live in areas where PM2.5 pollution regularly hits the Orange level. The Public Health Ministry states that prolonged exposure to high levels of PM2.5 can reduce human lifespan by as much as 1.78 years.
What is the government doing?
Phattarapong Leelaphat, MP for the opposition People’s Party in smog-hit Chiang Mai, is sceptical of the government’s claim it is making strenuous efforts to tackle the PM2.5 problem, saying the evidence suggests otherwise.
“I’m worried because there are no results in sight,” he said.
The government has offered subsidies to sugarcane farmers who refrain from setting fire to their crops, but few have taken up the incentive.
However, growing pressure to combat the crisis has spurred a greater sense of urgency among officials.
On Tuesday, the Industry Ministry ordered the closure of the Thai Udonthani Sugar Mill factory after it failed to comply with the ban on purchasing burned sugarcane.
The factory allegedly bought 400,000 tonnes of charred sugarcane harvested by burning 40,000 rai of farmland.
The following day, Prime Minister Paetongtarn Shinawatra instructed kamnans and village heads to compile lists of farmers who set fire to their land. Reports indicate the government will consider removing these farmers’ rights to state subsidies or compensation.
Bangkok governor Chadchart Sittipunt, meanwhile, has said that his administration is pushing for low-emission zones and will ban the entry of large trucks that do not comply with Euro 5 and 6 emission standards.
Euro 5 requires all diesel-run vehicles to be fitted with particulate filters to trap microscopic soot, while Euro 6 makes selective catalytic reduction or AdBlue systems mandatory for diesel-run vehicles to reduce nitrogen oxide emissions.
“We also intend to encourage people to work from home at times when PM2.5 levels turn Orange in more than 70% of the city for three consecutive days,” Chadchart said.
However, the latter call is merely a plea for cooperation, not a mandatory measure. When the Bangkok Metropolitan Administration pushed for work-from-home measures during last year’s smog crisis, only 151 organisations in the capital cooperated.
Hope for clean air
Assoc Prof Dr Kanongnij Sribuaiam, vice chair of the ad-hoc House committee examining the Clean Air Bill, said the legislative process is taking time because her panel has had to combine seven proposed draft laws and make big changes to whittle it down to just one draft.
“But we believe our draft will be ready for public review before the end of March,” she said.
If this deadline is met, there is a possibility that the Clean Air Bill will finally enter the second and third readings in April before Parliament goes into recess.
“The speed with which it is legislated will depend very much on politicians,” Kanongnij said.
Buntoon Srethasirote, a member of a separate House subcommittee on the Clean Air Bill, said secondary laws were also being drafted to support the legislation of the bill.
Meanwhile, Sonthi, the academic, said he had heard reports that the private sector is unhappy about having to pay financial penalties for pollution, as many companies say they are already complying with current laws, including those on the environment.
“Many are also concerned that current regulations could overlap with new rules and cause confusion,” he said.
