On April 6, 2023, the city of Chiang Mai in north Thailand temporarily became the most polluted city in the world. Unlike Thailand’s capital city, Bangkok, and other highly polluted cities, northern Thailand’s extreme seasonal air pollution is not due to fossil fuels and industrial activity. “Burning season” in Thailand drives poor air quality and is both a cause and consequence of poverty.

Slash-and-Burn Farming

“Burning season” in Thailand occurs every year from January to April when farmers in the north, particularly rice and sugarcane farmers, use a traditional practice to cultivate their farmland. This practice, tagged slash-and-burn agriculture, consists of farmers cutting down and burning the remaining vegetation from the previous harvest, with approximately 70% of rice straw being burned yearly. 

Slash-and-burn is a low-cost and efficient method of cultivation that effectively removes leftover agriculture and is thought to eliminate invasive plants and animals that may hinder future crop yields. The widespread use of this method led to the coining of the term “burning season,” which also refers to the high levels of pollution generated due to this technique.

The Problem with Burning Season 

While slash-and-burn practices are effective for farmers, the burning season has adverse impacts across Thailand, predominantly in the form of extreme, hazardous air pollution, which, in 2023, affected an estimated 1.7 million Thai citizens. The presence of PM2.5 pollution particles in the air has substantial consequences for human health, worsening preexisting conditions such as asthma and causing other conditions such as lung disease, cancer and sometimes premature death. In some areas of Thailand, such as Chiang Rai, PM2.5 levels were over 76 times higher than the World Health Organization’s (WHO) recommended exposure level. 

In Chiang Mai alone, pollution-induced illnesses caused the deaths of 1,800 people during the burning period. 

Burning Season Is Driven by Poverty 

Approximately 40% of Thai farmers live below the poverty line and rely on high crop yields to make a living, so naturally, they would resort to cheaper farming practices, such as slash-and-burn. 

Alternative options for these farmers, while less detrimental to air quality, are minimal due to their higher costs. For instance, a common method of clearing and cultivating agricultural land is using heavy machinery such as combine harvesters; however, this option is not always a feasible option for farmers in Thailand due to the expense of owning and operating machinery and the incompatibility between these machines and rice farming itself, which tends to be done in steep upland areas. Another alternative would be for farmers to hire laborers to cut manually and clear crops. Yet again, this process is costly and time-consuming, which, in turn, could lead to a delay in growing the next cycle of crops and generating income, thus worsening poverty. 

After burning vegetation, a nutrient-rich ash settles on the newly cleared land, providing farmers with a natural fertilizer to aid crop production in the following season. This process eliminates the need to buy manufactured fertilizers, which tend to be imported and costly. 

Burning Season Worsens Poverty

In just one week in March 2023, more than 200,000 Thai citizens were admitted to hospital with conditions caused by pollution. This figure indicates the human health consequences and presents economic challenges, particularly for those below the poverty line. Hospitalization and treatment come at a high cost, which is problematic for those without adequate health care plans. Additionally, families are at risk of income losses if they cannot work due to health problems, equally affecting local businesses that lose their employees. Businesses are also implicated by reduced consumerism due to sickness and advice to stay indoors during periods of high air pollution. 

Chiang Mai is a popular tourist destination, and tourism significantly contributes to the city’s GDP per capita. However, tourists are advised to avoid the city and other areas of northern Thailand during the burning season, leading to income losses for local businesses and employees, especially those working directly in the tourism sector. In fact, in 2019, the burning season in Thailand caused an 11% reduction in the nation’s gross domestic product. 

Government Policies Are not as Effective as They Seem

In 2019, the Thai government banned open burning, making it illegal for farmers to burn their land. While this ban is a seemingly positive advancement, it has been criticized as ineffective as farmers have resorted to burning their land at night to detract any attention from their now illegal practice. This response results from the government’s failure to provide Thai farmers with the resources to assist them in shifting away from slash-and-burn practices, such as providing grants or farming supplies. 

Innovative Solutions 

IQAir recommends that citizens wear facemasks, use air purifiers/filters, purchase air pollution monitors and avoid the outdoors during the burning season to protect themselves from PM2.5 pollution, yet this is not always feasible for those living in poverty.

However, Chiang Mai University has created and begun to install vending machines that provide citizens free face masks, air filters and purifiers, which remove the presence of PM2.5, in places such as schools and hospitals where the most vulnerable citizens are present. 

In the Chiang Rai province, the Rajamangala University of Technology Lanna recently developed a smartphone app known as “Smoke Watch,” which uses NASA satellite data and detailed data on fire “hotspots” to monitor fires in the region in real time. Local communities and firefighters receive alerts when there is nearby burning, providing information such as fire location and the fastest route to get there. This app allows for the fast elimination of fires and reduces the pollution they generate. In collaboration with organizations and NGOs, a second app, “Burn Watch,” is currently being developed. The app requires local farmers to submit requests to burn their land, allowing for more regulated and controlled burning. 

Thailand Clean Air Network 

The work of the nonprofit organization Thailand Clean Air Network (CAN) is leading the effort to alleviate the threat of air pollution caused by the burning season in Thailand. The organization comprises volunteer activists and academics who raise awareness of problems surrounding the burning season to the Thai government and the public. 

In 2022, Thailand CAN drafted the Clean Air Act, which discusses the various catalysts and consequences of the burning season while outlining potential solutions the government could implement. Thailand CAN is awaiting the Prime Minister’s endorsement to make the act official legislation. 

– Lucy Jacks
Photo: Wikimedia