THA TON, THAILAND – Researchers measured alarmingly high levels of toxic heavy metals in northern Thailand’s Kok River, as local fishers reported health problems and the loss of their livelihoods while officials struggled with a conflict-hit neighbor.
Fishers left without catch and battling rashes
Fisherman Kob Kotkam from Tha Ton had been unable to fish in the Kok River for months. He said he feared chemicals in the water and linked the collapse in fish stocks to the pollution.
He also complained of skin irritations, pustules and pimples all over his body, which he believed came from the river. Because of this, he said he could not currently continue his profession.
Chiang Mai testing finds arsenic and other metals
At Chiang Mai University, toxicologist Wan Viriya and his team examined water samples from the Kok River. They found heavy metals at concentrations that were clearly above the intended limit values.
The researchers took samples at seven different locations and observed that contamination increased toward the border with Myanmar. In addition to arsenic, they detected cadmium, bromine and mercury.
Suspected source: mines across the border
According to Viriya, he worked with scientists and environmentalists who, among others, analyzed satellite images with the Stimson Center. These images showed industrial sites just beyond the Thai border.
They indicated that directly across from Tha Ton in Myanmar there were two rare earth mines and a gold mine. From these operations, heavy metals could be released as waste products and apparently inadequately treated before entering the environment.
Rare earths, China and the global supply chain
Myanmar was among the major producers of rare earths and critical minerals used, for example, in magnets for wind turbines and electric vehicles. The material played a key role in global energy and technology supply chains.
According to those involved, raw material from Myanmar was transported to China for further processing, which held a dominant position in magnet production. Countries such as Germany were said to be heavily dependent on imports of rare earths.
Politics squeezed by civil war and blurred responsibilities
Thai authorities confirmed they were talking with Myanmar’s regime about cross-border pollution. The situation was described as difficult because Myanmar was in the midst of civil war and the military did not control all areas.
Unregulated mines were reported to be a serious problem in regions north of the border, including areas of Kachin and Shan. There, virtually no one appeared to take responsibility, even though many actors profited from mining.
Drinking water fears in Chiang Rai and village pressure
While official commissions were set up, further findings emerged. Poisonous substances were also detected in other waters such as the Salween River, and in Chiang Rai drinking water was already reported to show elevated arsenic levels.
In Tha Ton, affected residents demanded swift measures at a town hall meeting. They said they had sent letters to the Thai prime minister, to Xi Jinping and to Myanmar’s regime, while people were cautiously urged to drink bottled water.
Mekong as a conveyor – risk for an entire region
The Kok River flowed from Myanmar into Thailand and joined the Mekong just a few kilometers downstream. This meant pollutants could be carried further and spread over large areas.
Analyst Brian Eyler from the Stimson Center warned that the unregulated mines were not just a local problem, because the Mekong continued on to Laos, Cambodia and Vietnam. More than 60 million people in the lower Mekong basin depended on fisheries and agriculture in its catchment area.
Citizen scientists feed data into a risk map
Researchers were gradually creating a risk map to identify contaminated rivers and build a shared data basis. The mapping aimed to show where the heaviest impacts were likely to occur.
In Tha Ton, Kob Kotkam and others took part as so-called citizen scientists. They regularly collected water samples and sent them to Wan Viriya to provide at least reliable measurements in a situation where no quick political solution was in sight.