Mekong tributaries flowing from Myanmar to northern Thailand, once clear and pristine, have morphed into an ominous, murky shade of orange-yellow. The cause: abnormally high levels of arsenic. Satellite imaging has identified rare earth mining sites in Myanmar’s Shan State as the prime cause of devastating impacts on three Mekong tributary rivers.
Aweera Pakkamart, director of Regional Environmental and Pollution Control Office 1 (Chiang Mai) reported that “the Kok River showed high arsenic levels, while the Sai and Ruak rivers, also Mekong tributaries, had even higher levels, which in turn elevated the levels in the Mekong River.”
He warned, “This is no longer a local issue – it’s a regional cross-border, environmental crisis. The pollutants could reach the South China Sea.”
Satellite images indicate that rare earth mining is taking place in two locations in Mong Yawn, southern Mong Hsat, southern Shan State about 25 kilometers from the northern Thai border, opposite Mae Ai district of Chiang Mai province. All told there are 20 rare earth mines in southern Shan State that are believe to be the source of the pollution.
Assistant Professor Satian Chunta, who lectures on natural resources and environmental management at Chiang Rai’s Rajabhat University, informed The Diplomat, “The only effective way to tackle the problem is at its source, in Myanmar,” a failed state whose junta has lost control of vast swathes of the country – including zones where the mines are operating.
The gold and rare earth mining zones in southern Shan State, are under the control of the United Shan Wa Army (USWA) a China-backed militia providing security for Chinese-run mining sites.
In northern Thailand, the local economy has been devastated by the mining run-off. Water tests from the Kok and Sai rivers near Thailand’s border with Myanmar have revealed elevated arsenic levels, leading Thai officials to warn citizens to avoid contact with river water. Three rivers – the Kok, Sai, and Ruak – have been declared unsafe, and all living aquatic species unfit to eat.
A drone view of the Kok River near Thaton. Courtesy photo provided by Earth Thailand.
Protests and petitions have demanded that all rare earth mines linked to the arsenic contamination of the rivers disaster be closed down.
“The Thai government has no clear action plan to solve this toxic water problem,” Saengrawee Suweerakan, a river conservation activist from Thaton, one of the worst affected towns along the Kok River told The Diplomat. “We have demanded that farm crops as well as river water should be tested. But still they have not done it. They have also failed to provide a clear strategy for stopping the arsenic flow and restoring our river.”
Communities living along the devastated Kok River, along with The People’s Network to Protect the Kok, Sai, Ruak and the Mainstream Mekong Rivers – a northern Thailand-based coalition of environmental ngos, scientists, and local government officials – have held several protest rallies.
On June 5, World Environment Day, a wide cross-section of Chiang Rai people assembled on the banks of the murky Kok River. A street theater performance mourned the death of the river. The People’s Network handed over a petition to the Thai government’s deputy permanent secretary of the Interior Ministry, Khajorn Srichanonthai, in a ceremony held halfway across the bridge over the river.
A petition to address the pollution is submitted to the government’s deputy permanent secretary of the Interior Ministry, Khajorn Srichanonthai (right), in a ceremony held half-way across the bridge over the polluted Kok River. Photo by Tom Fawthrop.
The petition, addressed to Paetongtarn Shinawatra, then the prime minister of Thailand, read: “We, the local people, recognize that this cannot continue. This is a national security crisis affecting millions of lives. We therefore urge you to take all necessary steps to immediately shut down these mining operations.”
An independent online media group, Lanner, made up of former social activists and NGO workers, compiled data to assess the damage resulting from the Kok River becoming unusable. Their report pointed to significant losses across three main sectors – tourism, agriculture and fisheries – in 20 communities bordering the river. The total estimated loss reaches 1,300,006,731 baht ($40 million) per year.
How has the Thai government responded to the public outcry?
Several piecemeal policies have been proposed by the Thai government to alleviate the crisis, including plans for the construction of underwater sediment barriers in the Kok River. These barriers aim to reduce arsenic concentrations before the water reaches local communities.
However, Dr. Suebskul Kittanugron, manager and research associate at the Area-based-Social Innovation Research Center at Mae Fah Luang University, who has been doing regular testing of Kok River pollution, was not impressed by the government’s proposals. The Peoples Coalition has again urged the Thai government to drop the sediment barrier project as ill-considered, lacking both community consultation and any environment study.
Addressing a Chiang Rai roundtable on August 20, Suebskul commented, “We need to stop saying the pollution is within acceptable limits. People have a right to know the facts. The only real fix is to shut the mines for good and talk directly with authorities in China, and Myanmar.”
On the bridge over the polluted Kok River, government officials receive a petition at a rally opposing the pollution. Courtesy photo provided by Earth Thailand.
The Border War Sidelined the Poisoned River Crisis
At a time when northern Thailand community networks, local officials, and academics had been lobbying for the government to adopt a strong focus and clear strategy on this burgeoning crisis, the weak coalition government led by Paetongtarn – who was officially removed from office on August 29 – became embroiled in the Cambodia-Thailand border conflict, to the detriment of dealing with other emergencies.
Thailand’s Dr. Pavin Chachavalpongpun, a professor at the Centre for Southeast Asian Studies, Kyoto University, told The Diplomat, “It is absolutely crucial for Thailand and Cambodia, along with the media, to prioritize cooperation on the alarming arsenic contamination of the Mekong and its tributaries over the current border conflict.” He explained, “The environmental threat is a nontraditional national security issue with long-term, widespread impacts on the health, food security, and livelihoods of millions across the region,” as opposed to the more narrowly defined concept of national security of the state and territorial control over its borders.
There are dire fears of contamination spreading along the mainstream Mekong. At this point it is impossible to know how far rainy season floodwaters will disseminate toxic water farther downriver, to Cambodia.
Brian Eyler, co-lead at The Mekong Dam Monitor with the Stimson Foundation, is extremely worried that the pollution so far identified in Thailand’s river is just the tip of the iceberg. “At least 15 rare earth mines have also been identified on Laos’ Mekong tributaries,” he pointed out. “Some rivers enter the Mekong near Nakhon Phanom, Thailand, only a few hundred kilometers from Cambodia.”
”It behooves the Cambodian government to begin testing for arsenic and other toxins on the Mekong mainstream and the Tonle Sap immediately, to demonstrate the extensive scale of this looming public health crisis.”
So far only the Mekong River Commission (MRC) has recognized the potential threat to the Mekong region. Monitoring and laboratory testing has confirmed abnormal levels of arsenic at two points between Thailand and Laos.
MRC experts downplayed the degree of the disaster, terming it as a “moderately serious transboundary environmental issue affecting all three countries.” Thailand’s Busadee Santipitaks, CEO of the Mekong River Commission, convened a roundtable forum with civil society organizations in Chiang Rai, where she stressed the need for regional cooperation and dialogue with China.
Pavin observed that “media attention should shift from nationalistic rhetoric to raising public awareness about this urgent ecological crisis.” He added, “It’s absolutely crucial for Thailand and Cambodia, along with the media, to prioritize cooperation on the alarming arsenic contamination of the Mekong and its tributaries over the current border conflict.”
“A shared focus on this existential threat could not only lead to a viable solution but also build trust and de-escalate political tensions” between Thailand and Cambodia.
A theater group performs the dance of death mourning the Kok River. Photo by Tom Fawthrop.
Can Thailand Push Back Against China’s Rare Earth Imports From Shan State?
The demands of local communities and civil society in northern Thailand – that Chinese companies in Myanmar running rare earth mines that have poisoned their rivers should be shut down – clearly runs up against some formidable obstacles.
China’s domination of global supply chains for refined rare earth exports currently depends on Myanmar’s rare earth mines, which accounted for over 57 percent of China’s total rare earth imports in 2024. In other words, for Beijing, these toxic mining sites in Myanmar are an indispensable part of their domination of the global rare earth market.
The dark side of rare earth extraction previously caused environmental devastation in China, which resulted in new legislation to curb pollution. These environmental safeguards triggered many Chinese companies to move south and set up their operations across the border in Myanmar’s Kachin and Shan states in order to evade the new regulations.
In response to the Thai protest petitions received by the Chinese Embassy in Bangkok in June, the embassy responded via Facebook, saying China “attaches great importance to the incident of heavy metal contamination in tributaries of the Mekong River in Thailand.” Its statement called for resolution through “friendly dialogue.”
Beijing’s offer of “friendly dialogue” still falls far short of the call by Burmese environmental scholar Win Myo Tu that China take responsibility and ensure that its businesses in Myanmar are held accountable for their environmental impact.
China is not likely to make any concessions to the complaints of their downstream neighbors on the Mekong without serious pushback from the Thai government, supported by all the evidence of laboratory testing both by Thailand and the MRC.
But given China’s expanding influence on ethnic groups that control mining sites in Shan State – especially their long established proxy, the USWA – Beijing stands out as only party that can provide a solution in partnership with the MRC and regional governments.
“If China had the political will to address the issue, it could take several decisive actions,” Pavin pointed out. “It could enforce its own stringent environmental regulations on companies operating outside its borders, ensuring they adhere to the same standards as those within China.”
Other academic experts say Beijing should also provide direct financial and technical assistance to address the restoration of these rivers. China could also agree to establish joint monitoring and reporting mechanisms with the affected countries to ensure transparency and build confidence that the issue is being addressed seriously.
“The government keeps saying it’s too hard [to deal with China], but it hasn’t tried. What are we afraid of?” asked Suebskul, the academic with the Area-based-Social Innovation Research Center. “We need to do more. Villagers hit by toxic floods need answers. We want our lives back. Chiang Rai needs a center for heavy metal testing and more open reporting.”
A viable solution would need to be multifaceted: it would require a global framework for supply chain traceability and certification to ensure rare earth deposits are sourced ethically and sustainably.
Assistant Professor Dulyapak Preecharatch, president of the Regional Studies Association and lecturer in Southeast Asian Studies at Thammasat University, reflected on Thailand’s capacity to stand up the China and the USWA. He concluded, “If we want other countries to respect us, we must leverage our power projection strategy to counterbalance our power, such as through cultural power, trade, and investment. This will make the Wa and their allies more respectful of us.”
Most urgently, Thailand’s government needs to shift the focus away from conflict with Cambodia to the understanding that both nations must together confront a deadly common enemy: the arsenic poisoning that could kill both humans and much of the rich wildlife of the once mighty Mekong.