David Hutt
DW
18/09/2025
Rare-earth mining in Myanmar is polluting the Mekong River with toxic metals, threatening ecosystems, food security, and water supplies across mainland Southeast Asia.
China controls about 60% of global rare-earth production and nearly 90% of refining
Image: Supplied by a Global Witness partner
Ecologists are warning that mainland Southeast Asia faces a looming ecological disaster unless urgent steps are taken to address the rare-earth mining boom in war-torn Myanmar.
According to Global Witness, a London-based watchdog, Myanmar has become the world's largest source of heavy rare-earth elements. These minerals are essential for manufacturing high-tech products like wind turbines, electric vehicles and medical devices.
Most of these mines are located in Shan state, where civil war has raged since the 2021 military coup.
Earlier this year, Thailand's Department of Pollution Control found arsenic levels nearly four times higher than World Health Organization (WHO) limits in parts of the Kok River, a Mekong tributary flowing into Thailand from Myanmar. Other toxic metals were also detected at dangerous levels.
Rare-earth mining has exploded in Myanmar's Kachin region, making it the world's largest source of supplyImage: Supplied by a Global Witness partner
The Kok runs through northern Thailand's Chiang Rai province before merging with the Mekong, where arsenic concentrations have also reportedly been detected.
The Mekong is Southeast Asia's longest river, which provides a lifeline for millions. Experts fear the contamination could seep into irrigation systems that feed vast stretches of the region's farmland and drinking water supplies. The WHO has reportedthat prolonged exposure to arsenic and other metals can cause cancer, neurological disorders and organ failure.
"What we see now is just the beginning," Pianporn Deetes, campaigns director at International Rivers, a conservation NGO, told DW.
"If left unchecked, the situation could deteriorate rapidly — potentially hundreds of unregulated mines upstream, heavy contamination spreading through the Mekong and its tributaries, and ultimately acidification of waters reaching as far as the seas," she said.
Limited options
After petitions from local communities in June, Thai authorities proposed building underwater sediment barriers or mini-dams on the Kok to trap toxic deposits before they reach villages.
Environmental groups say such infrastructure will take years to complete, while the crisis is already unfolding.
Bangkok has few options. The problem lies largely within Myanmar's borders, particularly in Shan state, where new mines are located in territory controlled by the United Wa State Army (UWSA), a powerful China-backed militia that oversees two semi-autonomous enclaves.
Reuters has reported that the UWSA provides armed protection for Chinese-run mining operations there. Neither Myanmar's military rulers nor international organizations exert meaningful control over the region.
Currently, it is unknown whether the pollution has remained concentrated in northern Thailand or whether it has already leached into the Mekong, potentially affecting downstream nations.
The Kok runs through northern Thailand's Chiang Rai province before merging with the Mekong, where arsenic concentrations have also reportedly been detected.
The Mekong is Southeast Asia's longest river, which provides a lifeline for millions. Experts fear the contamination could seep into irrigation systems that feed vast stretches of the region's farmland and drinking water supplies. The WHO has reportedthat prolonged exposure to arsenic and other metals can cause cancer, neurological disorders and organ failure.
"What we see now is just the beginning," Pianporn Deetes, campaigns director at International Rivers, a conservation NGO, told DW.
"If left unchecked, the situation could deteriorate rapidly — potentially hundreds of unregulated mines upstream, heavy contamination spreading through the Mekong and its tributaries, and ultimately acidification of waters reaching as far as the seas," she said.
Limited options
After petitions from local communities in June, Thai authorities proposed building underwater sediment barriers or mini-dams on the Kok to trap toxic deposits before they reach villages.
Environmental groups say such infrastructure will take years to complete, while the crisis is already unfolding.
Bangkok has few options. The problem lies largely within Myanmar's borders, particularly in Shan state, where new mines are located in territory controlled by the United Wa State Army (UWSA), a powerful China-backed militia that oversees two semi-autonomous enclaves.
Reuters has reported that the UWSA provides armed protection for Chinese-run mining operations there. Neither Myanmar's military rulers nor international organizations exert meaningful control over the region.
Currently, it is unknown whether the pollution has remained concentrated in northern Thailand or whether it has already leached into the Mekong, potentially affecting downstream nations.
The Mekong river sustains agriculture, fishing, transport and commerce — and supports life in small villages and towns along its banks
Image: Sirachai Arunrugstichai/Getty Images
It is "extremely likely" that toxic metals and chemicals are already detectable in Cambodia, where 60% of the country's protein intake comes from wild-caught fish from the Mekong River, Brian Eyler, director of the Stimson Center's Southeast Asia Program, told DW.
In recent weeks, civil society groups have called for stronger action from the Mekong River Commission (MRC), an intergovernmental body set up by Cambodia, Laos, Thailand and Vietnam in the 1990s to manage the shared waterway.
"The MRC should urgently establish monitoring stations for heavy metals and ensure that communities across the basin have timely access to accurate and transparent information," Pianporn urged.
But the MRC has so far downplayed the threat. In July, it reported arsenic levels above safety limits at four of five sampling sites in Thailand and Laos, yet described the situation only as a "moderately serious transboundary environmental issue."
Many analysts agree that ultimate responsibility lies with Beijing, which controls about 60% of global rare-earth production and nearly 90% of refining.
China, the world's largest user of rare-earth minerals, outlawed many forms of rare-earth mining at home in the 2010s because of concerns about the environmental damage it brings.
However, 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.
It is "extremely likely" that toxic metals and chemicals are already detectable in Cambodia, where 60% of the country's protein intake comes from wild-caught fish from the Mekong River, Brian Eyler, director of the Stimson Center's Southeast Asia Program, told DW.
In recent weeks, civil society groups have called for stronger action from the Mekong River Commission (MRC), an intergovernmental body set up by Cambodia, Laos, Thailand and Vietnam in the 1990s to manage the shared waterway.
"The MRC should urgently establish monitoring stations for heavy metals and ensure that communities across the basin have timely access to accurate and transparent information," Pianporn urged.
But the MRC has so far downplayed the threat. In July, it reported arsenic levels above safety limits at four of five sampling sites in Thailand and Laos, yet described the situation only as a "moderately serious transboundary environmental issue."
Many analysts agree that ultimate responsibility lies with Beijing, which controls about 60% of global rare-earth production and nearly 90% of refining.
China, the world's largest user of rare-earth minerals, outlawed many forms of rare-earth mining at home in the 2010s because of concerns about the environmental damage it brings.
However, 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 2018, Myanmar's civilian-led government had banned exports and ordered Chinese miners to wind down operations, but since 2021, extraction has continued amid a widening civil conflict.
Beijing has "effectively exported demand for rare-earth mineral extraction to other countries. And now the practice has proliferated in Myanmar's ethnic autonomous regions next door, where it is booming in an unregulated fashion," said Eyler.
Could the situation worsen?
Beijing should guarantee that all rare-earth imports come only from mines that comply with its laws and environmental standards, Pianporn told DW.
"If China is serious about leading on 'ecological civilization,' it must act in an accountable and transparent way," she added.
However, a tougher response from Beijing would work against China's own self-interest, as the global race for rare earths is intensifying geopolitical struggle for control of these critical materials.
It would also go against the way China typically conducts foreign policy in regions like Southeast Asia, noted Assistant Professor Dulyapak Preecharatch, lecturer in Southeast Asian Studies at Thammasat University.
In bilateral dealings, China always emphasizes the principle of state sovereignty, in which Beijing stresses that it does not interfere in the affairs of another country, including its environmental legislation.
As such, Beijing can say that it has no influence over rare-earth mining in Myanmar because oversight of environmental damage falls within Myanmar's sovereignty, nor is there a need for China "to consider problems for other downstream states," Preecharatch told DW.
The rare-earth rush is not limited to Myanmar. At least 15 mines have been identified along tributaries of the Mekong in Laos. Cambodia currently lacks active large-scale rare-earth mines, but exploration is ongoing.
Environmentalists fear a regional chain reaction of pollution on the Mekong.
"This situation is likely going to get much worse before it gets any better," Eyler of the Stimson Center told DW.
"It's possible that the entire river's fish population becomes contaminated, and the floodplains, which are an agricultural production zone for the world, are unusable for a long period of time," he added.
For now, the Mekong is still seen as one of the world's great clean rivers. But experts fear that reputation may soon be lost.
Edited by: Keith Walker
David Hutt Journalist covering Europe-Southeast Asia relations
