Deputy PM Deploys Rapid Arsenic Sensor at Mae Sai Border
Deputy Prime Minister Yoschanan Wongwutthi visited the Thai-Myanmar border in Mae Sai to address arsenic contamination in the Sai River. He showcased the M-Sense sensor, a low-cost, portable device developed by NSTDA that detects arsenic and heavy metals in water within five minutes for just 60 baht per test. The government is also pursuing long-term sediment trap solutions and coordinating with China to tackle the pollution at its source.
Deputy Prime Minister and Minister of Higher Education, Science, Research and Innovation Yoschanan Wongwutthi visited the Mae Sai border area in Chiang Rai on November 15, 2026, to inspect the crisis of arsenic and heavy metal contamination in the Sai River. He brought advanced innovation from NSTDA that can be used in daily life to urgently assist local residents.
At the First Thai-Myanmar Friendship Bridge in Mae Sai District, a multi-agency team surveyed risk points along the riverbank where water remains visibly turbid and reddish. Yoschanan observed researchers from the National Nanotechnology Center (NANOTEC) at NSTDA demonstrating the M-Sense field test kit for arsenic and heavy metal contamination, applying it to solve real-world problems.
For the M-Sense test kit procedure, NSTDA researchers demonstrated and explained a process designed to be simple and uncomplicated. The main equipment consists of a test reagent and an electrode chip. The process begins by inserting the electrode chip into a reader connected to a computer program with pre-set measurement parameters.
A water sample is then mixed with the test reagent and shaken. Using a dropper, the mixed sample is placed onto the electrode chip, and processing is initiated via computer. The sensor system analyzes and displays the arsenic concentration as a clear numerical readout on the computer screen within just 3-5 minutes.
This mechanism allows M-Sense to measure water quality rapidly with results closely matching those from a central laboratory, but at a much lower cost of only 60 baht per test. This enables local agencies, public health officials, and even community leaders to access the tool for monitoring, screening, and quickly warning villagers to stop using water if arsenic levels spike above standards, helping reduce panic and prevent health impacts immediately.
Yoschanan addressed long-term management direction, stating that arsenic contamination is a regional priority the government treats with utmost importance. Although MHESI is not the lead agency directly responsible, the ministry seeks to support problem-solving and serve as a key backer in resolving the cross-border crisis. This aligns with bilateral talks between the Thai and Chinese prime ministers, which seriously raised the issue to coordinate cooperation in management and problem-solving from the source upstream.
Yoschanan added that academic data and water source analysis show arsenic and heavy metals tend to bind with turbidity or attach to sediment flowing with the current. Relevant agencies are therefore studying a sediment trap model or flow diversion system. When water flow slows, contaminated sediment settles to the riverbed, allowing machinery to dredge and remove it for proper and safe disposal, which would massively reduce arsenic levels in the Sai River ecosystem. This approach is being prepared for submission to the Cabinet.
