Thailand has requested assistance from Japan to identify the source of toxic water runoff from Myanmar’s Shan State, which officials warn is threatening the health of communities on both sides of the border.
Surin Worakitthamrong, Director of the Pollution Control Department (PCD), announced on 25 February that discussions are underway with the Japanese government regarding cooperation on water filtration technology and sediment analysis. The announcement was made during a water quality inspection of the Kok River in Chiang Rai Province.
According to Mr. Surin, Japan has expressed strong interest in supporting Thailand’s leadership on the issue, noting that Japanese experts have previously undertaken similar environmental projects in Myanmar.
“Japan will help us test for toxic metals in water and sediment samples. we hope to visit Shan State in the near future,” the director said.
Initial assessments suggest that the presence of arsenic in the Kok River likely stems from two primary sources: large-scale agricultural activities or rare-earth mining operations.
To monitor the situation, the PCD plans to establish eight monitoring stations along the Kok River and three along the Salween River. These stations are designed to provide real-time data on water quality and toxic metal levels to keep the public informed.
Recent tests of water samples showed arsenic levels of 0.005 mg/L, which currently remains within the safety limit of 0.1 mg/L. Experts consider these current testing methods to be approximately 80% accurate.
In a bid to ensure long-term water safety in Chiang Rai, officials will seek cabinet approval next month for a 2.25 billion baht (approx. $62 million) budget to construct a new water treatment plant in Mae Sai District.
The environmental crisis highlights the transboundary challenges facing the region as unregulated mining and industrial activities in conflict-affected areas of Myanmar continue to impact neighboring downstream nations.





