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From red to green: How indigenous villages in Thailand battle cross-border coal pollution

The ethnic Lua village of Nam Chang Pattana in Thailand’s Nan province straddles a mountain ridge, just a few kilometres away from the Laos border. Luke Duggleby/HaRDstories

In a former communist stronghold along the Thai-Lao border, indigenous communities are picking a new battle. Armed with litmus paper and test tubes, they are fighting transboundary pollution allegedly caused by the region’s largest coal power plant.


Perched 1,500 meters above sea level, Kanchanaporn Pang-ud, an indigenous woman, overlooks the Thai-Lao border. This mountainous region, historically a haven for revolutionaries during Thailand’s communist insurgency, confronts a new challenge. The environmental impact of Laos’s largest coal power plant, clearly visible from the young activist’s standpoint, looms over Thailand’s northern provinces.

“That’s not fog but emissions from the power plant,” says 30-year-old Kanchanaporn, peering through the early morning haze. She suspects that the Hongsa lignite plant, just a short hike across in Lao PDR territory, poses a significant threat to her and the indigenous Lua communities in Nan province. Since the plant opened in 2015, they have observed disturbing changes, notably unexplained black spots on their crops.

Concerns about transboundary pollution from the 1,878-megawatt power plant began to surface in 2013, with environmentalists highlighting its potential impact on northern Thailand’s air quality. The region is plagued annually by severe haze, a result of seasonal burning and linked to various health issues. Despite being the plant’s principal buyer and investor, Thailand has yet to officially recognise the plant’s role in this predicament.

Determined to uncover the truth, Kanchanaporn and a school friend have embarked on a citizen science mission, using basic tools like test tubes and litmus papers to investigate the plant’s cross-border environmental impact. “The more I learn, the clearer the answers, and the greater my fear,” she says.

Mapping the risks

Eighteen kilometres from the power plant lies Kanchanaporn’s home in Nam Chang Pattana village. After preparing breakfast for her family, the Lua woman loads her equipment box onto her motorcycle. Instead of the usual trip to the farm, she’s setting out for a scientific expedition.

Communities in Nan province first became aware of the coal power plant when transmitting poles and electricity lines, spanning the border between the two countries, encroached on several farms en route to the main power supplier. Farmers lodged lawsuits against the Electricity Generating Authority of Thailand, the primary purchaser of the electricity, seeking to halt the project. Despite the ongoing Supreme Court legal battles, electricity from Laos continues to be transmitted to Thailand through these lines.

Kanchanaporn first spotted browning spots on the leaves of rice in her family’s paddy. The local agricultural office attributed these symptoms to rice blast, a disease occurring when plants, weakened in their immune systems, succumb to fungal infections. Farmers observed similar symptoms in corn, their primary source of income.

Community members began speculating whether the coal plant is a contributing factor. “We’ve been harvesting rice and corn for generations,” said Kanchanaporn. “We can tell which plants perish from diseases and which from other causes.”

Their mounting doubts eventually led to the community’s citizen science initiative. In 2017, health experts and researchers from five institutions began gathering concerns from eight pilot villages along the Thai-Lao border, shaping pivotal research inquiries.

A research project, valued at 19 million baht (about $540,000) and financed by the Health Systems Research Institute, sought to assess environmental indicators such as air, soil, groundwater, and fish. The objective was to pinpoint potential contamination sources in the environment. 

The first step was to create a risk map that works like a compass to select the times and areas for studying the suspected transboundary pollution. Researchers combined meteorological and topographical data into computer models, enabling them to forecast wind directions and determine the likely deposition of air pollutants. This data was then linked with local insights on land and water use.

Reddened communities

Determined to prove the impact of the coal power plant, Kanchanaporn stepped forward to help with the research work and gather necessary samples. She collected soil samples and used litmus paper tests to ascertain their acidity levels. 

And then came a major breakthrough. The litmus paper turned red, showing that the soil in eight examined villages was acidic with pH-levels much lower than uncontaminated soil.

“When we realised that the wind patterns from Laos to Thailand aligned with the areas where our crops are failing, we thought ‘hey, this is probably it!’” said Kanchanaporn, who was recently honoured for her dedication to local service as Miss Red Star 2022, the community’s annual beauty pageant award, a nod to the area’s communist past.

While other factors could be impacting the crops, many studies highlight acid rain’s harmful effects on crop roots, destroying their natural defence system and making them vulnerable to disease. 

Acid rain forms when pollutants like sulphur dioxide and nitrogen dioxide, commonly released during coal burning, mix with rain. This kind of pollution can stem from various activities, including agricultural practices. But recent environmental studies and advanced computer simulations point to coal power plants as the primary source of acid rain.

Dr. Tanapon Phenrat, an environmental engineering professor at Naresuan University and the project’s lead researcher, noted, “Our computer model shows that from October to February each year, the seasonal winds flow from Laos to Thailand. While the findings aren’t definitive, the data strongly suggest the power plant as a major emission source.”

Some wondered if soil contamination might have been caused by gunfire during the communist insurgency between 1965 and 1982. At that time, Thailand’s communist party used these mountainous areas for training, involving farmers and students and coordinating with Laos and China. However, an engineering expert suggested that gunfire wouldn’t release the acidic chemicals associated with the observed contamination.

The study highlights that the agricultural losses in the eight affected communities could reach as much as 842.34 million baht (about $23.32 million) each year. Kanchanaporn’s home district of Chaloem Phrakiat borders Laos and is home to about 10,000 people, who mostly depend on farming for their livelihoods.

According to its website, the Hongsa power plant’s three units are highly automated, designed to meet stringent operating standards and optimize performance. The plant has monitored air quality, specifically checking for sulfur dioxide and nitrogen dioxide, in Laos’s Hongsa and Ngern districts.

However, it remains unclear whether there is consistent monitoring of air quality on the Thailand side of the border.

In October 2023, HaRDstories contacted Hongsa Power Company Limited for comment, but did not receive a reply. Company staff indicated that media inquiries require authorisation from the Lao PDR authorities, who are shareholders in the project.


Neurotoxic hair samples

In Namree Pattana village, just a few kilometres away, Napaporn Pongprasert balances working in her family’s mulberry orchard with addressing the health concerns of her fellow community members.

The 29-year-old Lua woman is a community health volunteer, a long-standing Ministry of Public Health programme empowering locals to lead health services. Napaporn has recently started wondering if the health issues that plague her community are linked to the coal-fired power plant located twenty kilometres from her village.

Napaporn has always been fascinated by science, but couldn’t pursue higher education due to financial constraints. So, when her friend Kanchanaporn invited her to be part of the citizen science team, she didn’t think twice to accept.

As part of the effort to understand the potential impact of the power plant on her community’s health, Napaporn has been collecting hair samples from local women to check for mercury. The neurotoxic metal is released with the gases rising up from the smokestacks of coal-burning power plants.

In 2021, the team discovered an average mercury level of 0.66 milligrams per kilogram in the samples, which is below the global health threshold of 1 milligram per kilogram. They also detected mercury contamination in fish from the community’s creeks.

Although the contamination levels are below international health safety standards, the available research suggests a need for caution.

Southeast Asia’s coal-fired power plants, including Hongsa, often don’t install mercury treatment systems, even though they are available,” noted Dr. Tanapon, the engineering professor.

Burning of coal, after artisanal gold mining, is the largest source of mercury air pollution. This global pollutant can travel large distances and accumulate as a toxin in organisms such as fish, moving up the food chain. 

Consuming fish contaminated with this heavy metal, poses significant health risks, especially for children and pregnant women. It is known to have neurological effects on brain development and was linked to lower IQ levels.

“Sometimes I think it’s better if I don’t know all about these things…but I have to know, so I can protect myself and the people in my village,” Napaporn said.

In Nan’s low-income communities, fish remains a vital source of protein. This is where the risk maps become crucial; they enable health volunteers to identify vulnerable groups for whom they can offer preventive guidance and, potentially, future blood tests.

Entering its second phase, this year-long programme encourages local farmers and students to monitor environmental changes by recording data via mobile phones for an online database linked to experts. Meanwhile, health volunteers, including Napaporn, are tracking health risks among vulnerable groups.

“This is a new approach to monitoring health impacts,” said Somporn Pengkham, the project’s manager and a former nurse. “It’s collaborative, with communities participating alongside project operators for better accuracy and to start early protective measures.”


Coal controversy

As night falls, Wanchai Buasaen’s little grocery store was illuminated by faint solar light. Like many in Nam Chang Pattana village, the 40-year-old village chief assistant installed the panels himself, a move driven by soaring electricity prices and the need to power inaccessible agricultural areas. Ironically, proximity to the power plant offers little energy security for the Lua community.

When construction began in 2010, the Hongsa power plant was hailed as a trailblazer in Laos, pledging energy security to both Lao and Thai communities. With plans to complete four additional plants boasting higher generation capacities within the next decade, coal-fired power output is projected to increase by up to 22 percent of total power generation by 2040.

Contrasting with the global trend towards reducing coal usage, Laos’s plan to build more coal power plants might jeopardise its efforts to reduce reliance on fossil fuels.

While the coal industry is relatively new to Laos, Thailand is gradually moving away from this fossil fuel. The Thai government is increasingly switching to alternative energy sources and has stopped the construction of new coal-fired plants.

Banpu Power Public Company Limited, a major coal mining player in Southeast Asia and a 40 percent stakeholder in Hongsa, closed its last Thai coal mine in 2008 after exhausting the reserves. The company has expanded its operations to various Asia-Pacific countries.

Hongsa is contracted to supply electricity to Thailand for 25 years, a term ending in 2040. This coincides with the United Nations’ target year for a complete coal phase-out, aimed at limiting the global temperature increase to below 1.5 degrees Celsius.

It is unclear if the Hongsa power plant will cease operations or continue producing energy beyond its current contract.

The United Nations Economic and Social Commission for Asia and the Pacific points out in a report on Laos’ energy strategy, “Soon there will be a point when it will be more economic to stop a coal-fired power plant and build a new solar plant, as the operating cost of a coal plant will outstrip the economic benefits.”

The next morning, puzzled, Wanchai looks at his corn that just caught the disease. Some local agricultural officers explained to him that climate change could play a part in making the crops vulnerable. “I’m not sure what the cause is – the coal power plant contamination or the changing climate?”


Transboundary accountability?

Hongsa is not the only cross-border investment project that local communities are concerned about.

In 2017, communities in southern Myanmar faced land grabbing and pollution from the Ban Chaung coal mine, a venture co-invested by Thai companies. Similarly, in northeastern Thailand, local ecosystems and communities have been disrupted by the Xayaburi hydropower dam, a project of Thai energy conglomerates on the Mekong River.

According to Worawan Sukraroek from the Extraterritorial Obligations Watch Coalition (ETOs Watch), several factors drive this trend. “Access to cheaper natural resources and weaker environmental laws in neighbouring countries compared to Thailand are key drivers,” she explained.

Reports on the environmental and health impacts faced by communities near Laos’s power plants are scarce. The country’s restricted civil liberties, with a score of 13 out of 100 in the 2023 Freedom House assessment, one of the worst in the region, hinder transparency and information flow.

In Thailand, where freedom of expression is relatively more secure, citizen science reports have unveiled air pollution impacts crossing national borders. This underscores the urgency of Transboundary Environmental Impact Assessments (TEIA), according to Worawan.

Currently, TEIA, a mechanism to assess projects environmental impact across country borders, lacks legal binding in both Thailand and Laos, a concern echoed by Lua community members who worry about their limited judicial power over cross-border issues.

Thailand’s collaboration with neighbours, including Laos, targets transborder pollution but mainly focuses on seasonal forest fires and agricultural burning. Industrial emissions remain notably absent from these efforts.

However, persistent advocacy by civil society in Thailand has begun to influence authorities to consider the concept of transboundary impacts.

In October 2023, ETOs Watch brought the Hongsa case to the attention of Thailand’s National Human Rights Committee, which is now investigating the cross-border impacts and exploring how Thai businesses could offer protection and compensation to affected communities.

In response to global concerns about human rights violations in business practices, the Thai government, in a May 2017 cabinet resolution, mandated the creation of mechanisms to regulate Thai investors abroad.

Located in Lao PDR, the Hongsa power plant is significantly tied to Thailand. It not only supplies most of its electricity to the country, but 80 percent of its shares are also owned by Thai energy companies. Its construction was financed by loans from nine Thai banks, marking it as the largest project loan in the Thai bank market.

“Transboundary Environmental Impact Assessment for investment projects is a very ambitious goal because of the legal hurdles,” Worawan from ETOs Watch notes. “That’s why we are pushing for local communities to participate in impact assessment projects [as a first step].”

Kanchanaporn and Napaporn joined the research project motivated by an earnest desire to use scientific insights to better the lives of their people. The two young Lua women represent a new forward-thinking generation, who understand that the future of their way of life hinges on the health of the environment. And they stand ready to do whatever it takes to fight for the protection of their mountainous home.

“If you live up here, hard work is enough to harvest your own food,” said Kanachaporn. “But it might not stay like this, so we need to do everything we can.” Napaporn added: “We have to focus on the future, or it might be too late to fix it.”

Nicha Wachpanich is a Bangkok-based journalist covering stories from a rights-based and human-interest perspective. She previously worked with a local environmental news agency under Thai Society of Environmental Journalists. 

Luke Duggleby is a Bangkok based photographer. He regularly works on stories related to the environment and the impact of pollution and development on local communities.

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