People might forget about pollution during the monsoon season, but there is another season—the smoke season—when there is a high concentration of PM2.5, or ultrafine particles in the air. This causes long-lasting health impacts for people who are exposed to it. Nakhon Phanom is one of the provinces that has been seriously affected by air pollution.
Statistics from November 2024 to March 2025 show that Nakhon Phanom had the highest PM 2.5 index in the country. On March 26, 2025, the level of concentration was as high as 175.9 micrograms per cubic meter, or an equivalent of AQI 251—considered very unhealthy.
This raises the question of why Nakhon Phanom, a small province in Isaan with a population just over 700,000, could become such a hot spot for air pollution.
A map shows hot spots in Thailand and Laos on February 10, 2025 (Fire Information for ResourceManagement System)
Transboundary haze from Laos
The main factor that drove the spike of PM 2.5 concentration in Nakhon Phanom during that period was something called “transboundary haze.” This is air pollution caused by open burning in neighboring countries, especially cropland burning during the harvest season.
Data from several sources indicates that over 70 percent of burning spots that affected Nakhon Phanom were in neighboring Laos.
The Fire Information for Resource Management System and GlobalForestWatch websites show a lot of hot spots in Laos in February this year.
There were 112 recorded hot spots in Laos on February 3, and within a week this nearly doubled, to 216 spots. In the last week of February, 150 hot spots were recorded in Laos.
March was the month when Laos had the highest recorded number of hot spots. On March 3, a total of 227 hot spots were recorded. That number went up to 263 a week later.
The following weeks saw those burning spots increase dramatically, to 560, and then peak at 2,462 spots in the third week of March, before dropping back to 1,104 in the last week of the month.
According to GlobalForestWatch, there were 358 reports of fire in the Lao capital Vientiane during the first quarter of 2025. The situation appeared to be worse in southern Laos, with 418 reports of fire in Attapeu and 396 in Sekong during the same period.
Forest fire season in Laos, especially in the central province of Xaisomboun, usually starts in late February and lasts around 12 weeks. This is another source of microscopic dust that wafts over Thailand’s Isaan region, particularly in Bueng Kan, Nong Khai, Nakhon Phanom, and Mukdahan provinces.
GlobalForestWatch recorded 7,671 reports of forest fires in Laos during the year between June 2024 and June 2025. Data in 2020 showed that Laos had 18 million hectares of natural forestlands, and that it lost 355,000 hectares of forest in the same year due to forest fires. These fires likely emitted an equivalent of 185 million metric tons of carbon dioxide.
In 2023, Laos saw more than 18,000 reports of forest fires, the highest since 2012.
There are many causes of forest fires across Laos. There are both unintentional and intentional man-made causes, such as field burning to convert land to agricultural purposes. These fires are also aggravated by climate change.
Rice fields burning
Open burning has been cited as a main source of PM 2.5 by Thailand’s Department of Pollution Control, though other sources of this particulate matter also include vehicle exhaust, factories, and construction. Although air pollution problems have not been given as much attention in Isaan as in Bangkok and northern Thailand, data shows that the amount of open burning in the area has been increasing.
According to Rocket Media Lab, in 2024 Isaan had the second highest area of land burning in the country, after northern Thailand. However, the Isaan region also saw the highest percentage increase—over 506%—of land burning in the country in a span of a year. A total of 938,666 rai of land were burned in Isaan in 2023, but that number spiked to 5,692,127 rai in 2024. Rice fields were the type of land most often burned.
Therefore, transboundary haze was not the only source of air pollution in Nakhon Phanom; there was also a lot of field burning within the province. Data indicates that most of the hot spots within the province were from agricultural burning.
In March 2025, Pla Pak district chief Warakorn Panpetch observed the burning situation in the district. He found that, most of the time, people intended to burn only specific fields but were unable to control the fire, which then spread to other fields nearby and caused more damage.
Although the Nakhon Phanom provincial authorities earlier this year issued a regulation aimed at control of open burning, which calls for prison sentences for people who use the practice, little has been achieved. The province has not introduced any measures to benefit farmers who opt not to burn their fields.
Roi Et is another province that has seen a dramatic increase in open burning. In 2023, it recorded 18,616 rai of land burned. This number grew to 476,786 rai in 2024—a 2,461% increase—according to Rocket Media Lab.
The impacts
Land and forest fires, both outside Thailand and domestically, have caused severe air pollution in Nakhon Phanom and had negative health impacts on people there.
Without a sustainable solution, it is likely that the number of patients with respiratory diseases and other diseases associated with air pollution will increase. This will inevitably impose higher burdens on healthcare workers and Thailand’s overall healthcare system.
The haze also reduces visibility and can cause risks to transportation, whether by land, water, or air. It affects outdoor activities and disrupts people’s daily routines.
Air pollution is also bad for tourism. During the haze season, when the sky becomes gray due to high concentration of dust, the number of tourists to Nakhon Phanom significantly decreases, a major blow to local businesses and the economy.
This work is a collaborative effort among participants in the “Hands-On Fake News Detection Workshop in Isaan” program. If you suspect any content or messages that are incorrect, please send them to us for verification via Facebook at The Isaan Record or email at [email protected] This fact-checking initiative is supported by the U.S. Embassy Bangkok.
