THA TON, Thailand — The Wat Tha Ton Temple sits high above the tourist town of Tha Ton, with a magnificent view of the Kok River valley to the south and an equally impressive view of the river winding its way out of the mountains of Myanmar from the north. Prasert Guytuan, a local school worker, says people here first started noticing a problem with the river about two years ago, when a mine just across the border in Myanmar started production and the water got a little murky and itchy. But it wasn't too bad, he says, until this February, when the water didn't clear as it normally would during the dry season.
"In the past, the river was central to village life. When it cleared, people would come down to bathe in it and use it for cleaning and other things. But after people started getting skin rashes, we realized it was unsafe, and people started avoiding it," Guytuan says.
That's when the Department of Pollution Control started testing the water, and found arsenic levels nearly four times the World Health Organization (WHO) limits, and unsafe levels of other hazardous metals, in a river that flows some 150 miles through Thailand's Chiang Rai province before emptying into Southeast Asia's biggest and longest river, the Mekong — where unsafe levels of arsenic were also detected earlier this month. Pianporn Deetes is the regional campaign director for the NGO International Rivers.
"It's not safe anymore. And this is the water source that people are using for irrigation, for farming, for fishing and for their cultural activities," Pianporn says.
Pianporn and other activists blame unregulated gold and rare earth mining in Myanmar's neighboring Shan state for the transborder pollution. Rare earth minerals are critical components for manufacturing in planes, electric vehicles, smartphones, even military aircraft. The vast majority of their production is controlled by China, and the world's insatiable appetite for rare earths has led to a boom in unregulated mining in neighboring Myanmar. And it's not just the Kok River that's been affected.
Bundit Pantarakon is a local businessman and city council member in Mae Sai, about 60 miles northeast of Tha Ton on the Sai River which forms the border between Thailand and Myanmar.
"There are three mines closest to us. The nearest one is probably 10 kilometers upstream, then another about 20 kilometers and the furthest around 40. You can see them on google earth. And they use the Sai River itself to wash everything away," Bundit says.
Bundit also leads a community flood relief team in Mae Sai, and shows a rash on his hand he got while rescuing people from flooding a few weeks ago — a rash he blames on toxic metals in the water. After the flooding in May, the local government tested the well water in six houses along the river, he says. All but one had arsenic levels well above the WHO limit. Both the Sai and the Kok rivers flow into the Mekong, as does the Ruak, where unsafe levels of arsenic have also been found. Residents have been warned not to use the water from the rivers. Even elephant camps — a big tourist draw — won't let their animals bathe in it, either.
"This is just the first chapter of the disaster that's going to happen to the people, population along the Kok, along the Sai River and along the Mekong," Pianporn Deetes, from International Rivers, says. She says the ongoing civil war in neighboring Myanmar has only exacerbated the problem.
"This is the most unreported major issue in the Mekong happening now. And it's happening upstream in Myanmar where there's no governance," says Brian Eyler, who heads the Southeast Asia program at the Stimson Center in Washington, D.C.
"This is like the Wild West in the United States when you could go and mine anywhere without any regulation and pollute as much as you want. And there's no one to stop them," he says, "and I don't know how it can end."
That's because the area in question is controlled by the United Wa State Army (UWSA), a heavily armed ethnic militia with longstanding links to drug trafficking, arms trafficking and other illicit activities. In conflict ridden Myanmar, the UWSA have carved out an autonomous enclave complete with their own government, armed and supported by neighboring China. The UWSA declined comment for this story, even as recent maps from the Shan Human Rights Foundation show a sharp uptick in the number of new mines in the past several years. David Merriman leads the rare earths team at the market intelligence firm Project Blue.
"There is trade data showing the export of rare earth products from Myanmar into China," Merriman says, "And that's been growing significantly in the past several years but now it seems much more diverse."
By some estimates, China now imports roughly half its rare earths from Myanmar. In part, Merriman says, because of Beijing enacting tougher environmental regulations at home in 2015, regulations that pushed Chinese firms to set up shop with local partners next door. The resulting environmental damage in Myanmar's northern Kachin state has been well documented. In Shan state it's just beginning, though Merriman says China's involvement in Shan state seems more limited.
"Certainly, there is influence and there is likely to have been some initial help in setting up some of these assets," Merriman says, "but it's not like this is a Chinese government operation having control over the outputs and such. It is controlled by the UWSA."
Merriman adds: "China is essentially saying look, this is not our problem, this is your responsibility to operate mines how you operate in your country, but we will happily buy all your product. That's really the situation in a nutshell."
And that's the part that scares activist Niwat Roykaew the most. Niwat lives on the Mekong, about 70 miles south of Mae Sai. Niwat won the 2022 Goldman Environmental Prize for persuading the Thai government to scrap plans to allow China to blast a stretch of rapids on the Mekong to allow better access for Chinese cargo ships. He's also highlighted the environmental damage caused by China's damming of the Mekong, and the problems it's created downstream for tens of millions who rely on the river for their livelihoods. But both of those threats, he says, pale in comparison to the one posed by the unregulated mining.
"Yes, it's a catastrophe," Niwat says. "It's a disaster. Because these are toxins [that get into the water] and they manifest rapidly, and affect not only humans," he says, "but also animals and vegetation and they get into the food supply."
Niwat says China is the only country with any influence over the UWSA. And he wants Beijing to use that influence to end the mining, or at least persuade the UWSA to take steps to mitigate the damage it causes by using proper containment techniques. It's a tall order, given China's, and the world's, insatiable appetite for rare earths. But he says it's the neighborly thing to do, especially given the great power competition between China and the U.S. in the region. Not to mention the economic benefit, Niwat says, of maintaining friendly relations with downstream neighbors. He's heartened by a statement from the Chinese embassy last month that said it attached "great importance to the incident of heavy metal contamination" in tributaries of the Mekong River in Thailand, and called for resolution through "friendly dialogue." Niwat says he's also been contacted by the Chinese consulate to discuss the issue. He says that's a start, but vows to keep up the pressure for something more concrete.
Copyright 2025 NPR
