5 December 2025- Villagers along the Salween River in Mae Hong Son remain uncertain about whether fish and riverbank crops are safe to eat, following conflicting government statements on heavy-metal contamination. The confusion emerged prominently during the annual “Restore Life to the Salween” event held on 5 December at Ban Mae Sam Lab in Sob Moei district, where more than 200 people—from both the Thai and Karen State sides of the river—gathered for environmental activities and discussions on pollution.
The event was co-hosted by the WISE Foundation, the Mae Sam Lab Tambon Administrative Organisation, Salween National Park, local schools, and civil society networks. Expert speakers were invited to brief participants on the latest findings of arsenic and mercury contamination in the river.
Waiying Thongbue, president of the WISE Foundation, said ethnic communities gather each year to demonstrate their commitment to protecting the Salween Basin. “This year, however, the gathering comes with anxiety over contamination,” he said, urging residents to continue safeguarding the river.
Pianporn (Pai) Deetes, executive director of the Rivers and Rights Foundation, and the Hill Area Community Development Foundation, warned that satellite imagery now shows more than 150 mining sites in the upper Salween Basin, including rare-earth operations in Shan State under UWSA influence. These sites, she said, are likely the source of toxic heavy metals recently detected in the river.
“The public must be informed so they can avoid health risks and demand accountability,” she said. “Authorities must investigate who owns these mines and what chemicals are entering the headwaters. If left unchecked, unregulated mining will expand and the damage will be far more severe.”
Environmental pollution expert Apinya Kadkhuntod from the CHIA Platform expressed concern over drinking water and food contamination. Arsenic, she noted, is carcinogenic and accumulates in the body over many years. She advised residents to avoid direct use of Salween water, rely on cleaner tributaries or tap systems, and limit consumption of riverbank vegetables and large predatory fish. “Boiling does not remove arsenic dissolved in water,” she said.
The mixed messages from agencies have unsettled villagers. Mae Sam Lab village headman Supap Nuchanongkran said he has advised residents through the village loudspeaker, but people remain unsure. “Officials say vegetables and fish are within safety limits but should not be eaten frequently. This has confused villagers,” he said.
Despite official assurances, many residents are avoiding fish entirely, causing incomes to collapse. “Fishermen who used to earn tens of thousands of baht a month now have no buyers,” he said. Farmers are also hesitant to plant crops along the riverbank.
Local leaders have urged the government to secure safer water sources, such as diverting water from the Mae Por creek, which flows year-round, for household use.
Sathan Cheewawichaipong, coordinator of the Yuam–Ngao–Moei–Salween People’s Network, said some villagers remain unaware of the contamination due to communication gaps. “People worry about fish and riverbank crops, especially since fish migrate from the contaminated main river,” he said. He added that testing should include shrimp and shellfish, not only fish.
Assoc Prof Apinun Suvarnaraksha, dean of fisheries technology at Maejo University, said there is still no conclusive evidence on contamination levels in fish. “For now, people should avoid eating them until we have clearer results,” he said, adding that more definitive findings may be available within two or three months.
He noted that lessons from heavy-metal contamination in the Kok, Sai, Ruak and Mekong rivers in Chiang Rai should guide the government’s response. “If authorities delay because they assume the impact is minimal, the problem will worsen. With signs now appearing in the Salween, the government must urgently convene experts to develop a coordinated plan—information that will also be important for discussions with Myanmar.”
