As Thailand’s capital grapples with hazardous levels of PM2.5 concentrations, air pollution has again risen to the top of the country’s national agenda. This fine particulate matter, responsible for numerous health issues, has reached alarming levels in recent weeks, blanketing the capital in a toxic haze reminiscent of the infamous London Smog of 1952. However, while London’s catastrophe occurred in an era of industrial expansion with limited environmental awareness, Thailand faces a similar crisis in the 21st century – a time when clean air should be a universal right.
PM2.5, or particulate matter smaller than 2.5 microns, poses severe risks to public health. Prolonged exposure is linked to respiratory and cardiovascular diseases, as well as premature death. As of January 25, air pollution levels in Bangkok were critical, with the city ranked 6th globally for the worst air quality. On that day, the Air Quality Index (AQI) for Bangkok reached 181, indicating harmful air quality for everyone. Nakhon Pathom, a nearby province, recorded an AQI of 225, within the “hazardous” range.
Since 2019, air pollution levels in Bangkok have surged, with PM2.5 concentrations regularly exceeding safe limits. However, the crisis has existed for much longer, especially in the northern provinces. The urgency of the PM2.5 crisis was tragically highlighted by the case of Dr. Kritthai Thanasombatkul, a medical lecturer at Chiang Mai University who died from lung cancer at the age of 29 in 2023. Despite his healthy lifestyle, experts suspect his death was linked to prolonged exposure to PM2.5, underscoring the silent toll of air pollution.
This tragedy, alongside rising reports of chronic respiratory illnesses and nosebleeds in Thai children, demands immediate action. With PM2.5 levels at extreme highs, Bangkok, as the capital, has again drawn attention to the crisis, prompting urgent parliamentary discussions.
The ongoing pollution crisis infringes upon the fundamental right to clean air – an essential element of the broader right to a safe and sustainable environment. This right is enshrined in international human rights frameworks, including the 2018 United Nations resolution on the right to a clean, healthy, and sustainable environment, which links environmental conditions directly to the enjoyment of other rights, such as life and health. For Thailand, deteriorating air quality threatens its constitutional obligation to protect citizens’ health, as outlined in both domestic law and international human rights treaties.
The government’s promised Clean Air Bill, which is intended to introduce stricter regulations and improve air quality, has faced significant delays. Legislative resistance from influential industrial and agricultural stakeholders, coupled with political apathy and limited public awareness, has hindered its progress. Without a comprehensive legal framework to address the sources of PM2.5 – such as agricultural burning and industrial emissions – efforts to mitigate the crisis remain piecemeal and fragmented.
“Black Snow”
A major contributor to air pollution is the agricultural sector, particularly the sugarcane, rice, and corn industries. While agricultural burning is widespread, the sugarcane industry has recently been highlighted as a key cause of the current PM2.5 crisis. In Thailand’s rural areas, especially during the sugarcane harvesting season, a phenomenon known as “black snow” can be observed. This “snow” isn’t made of ice, but rather soot from sugarcane leaves that are burned to facilitate harvesting. These particles, carried by the wind, fall to the ground like snow, blanketing the area in dark, polluted dust.
With an anticipated record sugarcane yield of 92 million tons for the 2023/2024 production season, farmers are increasingly relying on burning to reduce production costs. Though the government has proposed a 120-baht subsidy per ton for farmers who cut fresh cane instead of burning it, delays in implementation have left many farmers with little incentive to switch methods. Further complicating the issue are sugar mills, such as those in Suphanburi, Udon Thani, and Kalasin, which continue to purchase large quantities of burnt cane. For instance, the Suphanburi mill buys nearly 59 percent of its cane from burned fields, encouraging the practice despite its environmental harm.
This issue is exacerbated in northeastern Thailand, where rising production costs and falling sugarcane prices make burning more financially attractive. While the government has promised subsidies for fresh-cut cane, delays in implementation and inconsistent enforcement have hindered progress. Until more consistent measures are introduced, the burning of sugarcane will likely remain a major contributor to Thailand’s PM2.5 crisis.
According to the Bank of Thailand, burning sugarcane is cheaper and faster than cutting fresh cane, which requires more labor and higher costs. Farmers can earn an additional 100 baht per ton by delivering burned cane. However, this practice releases significant amounts of PM2.5 into the atmosphere. Despite government measures, such as burn bans and promoting mechanization, enforcement has been weak, and many small-scale farmers lack the resources to transition to more sustainable practices. The limited availability of machinery and challenging terrain further complicate the shift away from burning.
Although vehicular emissions account for 60 percent of the pollution in Bangkok and surrounding areas, the air pollutants recently blowing in from provinces that have been burning sugarcane have worsened the situation. Bangkok’s eastern districts, aptly nicknamed “Klong Sam Wa Hill” by Pimkarn Kiratiwirapakorn, an MP from the opposition Move Forward Party, due to the eerie atmosphere of Silent Hill, serve as a grim reminder of the severity of air pollution caused by biomass burning.
The Bangkok Metropolitan Administration (BMA) has initiated emergency measures, such as urging residents to stay indoors, banning some trucks from entering central Bangkok, and increasing its air quality monitoring. However, these short-term responses fail to address the systemic issues underpinning the crisis. Addressing PM2.5 requires robust, long-term strategies, including investments in cleaner agricultural technologies, incentives for sustainable practices, and stricter regulations on industrial and vehicular emissions. Crucially, a participatory approach involving farmers, policymakers, and civil society is needed if the government is to craft sustainable solutions to the pollution problem.
The PM2.5 crisis in Thailand is not only an environmental disaster; it is also arguably an environmental crime with significant human health consequences. This pollution can be understood as a form of secondary green crime, arising from the exploitation of natural resources and violations of environmental regulations, such as burning in the face of existing bans. Additionally, state-corporate crime theory highlights the troubling role of both state and corporate interests in perpetuating these harmful practices for economic gain.
In Thailand, the failure to effectively enforce burn bans and the economic incentives within the agricultural sector, particularly sugarcane farming, expose a clear case of collusion between state and corporate actors. For instance, sugarcane mills continue to purchase burnt cane because it is more cost-effective than processing fresh-cut cane, all while public health and environmental protection are sacrificed. This alignment of economic interests underscores the urgent need for stronger regulations and enforcement to address these harmful practices.
Lessons from Singapore and China
Singapore offers a powerful example of how decisive government action can address air pollution. Once severely impacted by transboundary haze from forest fires in neighboring Indonesia, Singapore took a major step to address the problem in 2014 by passing the Transboundary Haze Pollution Act. This law holds companies accountable for environmentally harmful activities, even if the actions occur outside Singapore’s borders, imposing criminal and civil penalties on offenders. The government also sanctioned companies involved in illegal deforestation while encouraging eco-friendly practices. These policies, combined with regional cooperation and investments in clean technologies, have resulted in a marked reduction in air pollution.
Similarly, China, once notorious for its severe air pollution, implemented aggressive air pollution control plans starting in 2013. Since declaring its “war against pollution,” China has seen a steady decline in fine particulate air pollution (PM2.5). By 2021, pollution levels had dropped by 42 percent compared to 2013. By 2025, China aims to reduce PM2.5 levels by 10 percent from 2020 levels, further its transition to renewable energy sources, and reduce coal usage. Key strategies include promoting electric vehicles, transitioning to cleaner energy, and increasing urban green spaces. The creation of environmental police units and stricter regulations have been central to these efforts. Like Singapore, China’s commitment to regulation and clean energy technologies has helped turn its environmental crisis around.
Thailand, however, remains far from achieving similar progress. While air pollution in the country is not a new phenomenon, with records of industrial activity contributing to poor air quality as far back as the reign of King Rama IV (r.1858-1861), little has changed over the decades. With mounting evidence of the health and environmental costs, Thailand must urgently draw lessons from Singapore and China’s approaches, strengthening enforcement, holding corporations accountable, investing in sustainable alternatives, and transitioning to cleaner forms of energy.
Thailand’s ongoing PM2.5 crisis demands immediate, systemic change. Vulnerable populations, especially children, are suffering the consequences of polluted air—an injustice that cannot be ignored. The government must act to protect the right to clean air for all citizens, not just the privileged few. The Clean Air Act offers a promising step forward, but it must be passed and enforced with urgency. Holding corporations accountable, strengthening air quality standards, and ensuring equitable solutions are essential. History will judge us by how we respond.