Transborder News, April 21, 2025 — Penchom Saetang, Director of Ecological Alert and Recovery–Thailand (EARTH), has warned that unless immediate action is taken, the heavy metal contamination detected in the Kok and Sai Rivers in Chiang Mai and Chiang Rai provinces will escalate, causing widespread and long-term damage to communities.
Penchom explained that gold mining and ore extraction processes, believed to originate from operations in Myanmar near the Thai border, are the root cause of the arsenic pollution. Arsenic, a toxic element, does not break down naturally and will continue to accumulate over time, posing long-term health risks. Other hazardous substances such as cadmium and various ore-related chemicals could also be present. The chemicals used in the ore flotation and extraction processes, including potential use of cyanide or mercury, remain unclear — but are extremely dangerous, she said.
“The problem must be tackled at the source, which lies in Myanmar territory and involves Chinese-backed mining operations that likely operate illegally and without environmental safeguards,” Penchom emphasized. “Without urgent intervention, pollutants will continue to spill into Thailand indefinitely.”
She pointed out that mining activities near the border are relatively recent, and gold mining typically continues for decades — meaning the risk will intensify unless addressed now. Penchom called for the establishment of a bilateral commission to negotiate with Myanmar, stressing that the Thai government alone cannot solve the crisis, especially given Myanmar’s internal instability and lack of regulatory control.
When asked what local residents living along contaminated rivers should do, Penchom urged the Thai government and Ministry of Natural Resources and Environment (MNRE) to implement an emergency monitoring program. Environmental agencies must conduct regular monthly tests for chemical contaminants in water sources, publicly report the findings, and help residents protect themselves.
Regarding concerns over the use of raw river water for municipal water supplies, Penchom acknowledged that some heavy metals might be filtered during treatment. However, she stressed that authorities must transparently publish water quality data to reassure the public. She recommended that villagers independently send tap water samples to institutions such as Chiang Mai University for verification.
“Heavy metals often accumulate in riverbed sediments rather than the water itself,” Penchom added. “Arsenic is a known carcinogen. Long-term exposure above safety standards raises the risk of diseases such as skin cancer.”
She advised against using untreated river water for irrigation or consumption, warning that arsenic can accumulate in crops. “This is a serious long-term threat,” Penchom said. “If action isn’t taken now, the damage will be irreversible.”
Asked whether farmers could still use Kok River water for rice farming, Penchom replied that it remains uncertain. Testing of soil sediments and crops for arsenic contamination is essential and should be conducted by agencies like the Department of Agriculture.
Responding to concerns about arsenic levels detected in Chiang Rai, which lies several dozen kilometers from the mining sites, Penchom explained that the widespread contamination likely reflects the lack of proper tailing ponds and filtration at the mining sites. As a result, pollutants have traveled over 100 kilometers downstream.
When asked about the risks from mudflows during future flooding events — as seen during the major September 2024 floods — Penchom confirmed that heavy metals could contaminate the flood sediments, increasing exposure risks. She urged immediate government action to establish continuous monitoring.
“Communities must formally petition the government and MNRE to create a permanent monitoring task force,” she said. “This is a matter of public health affecting a vast number of people.”
Meanwhile, the Environmental and Pollution Control Office (EPCO) Region 1 in Chiang Mai reported that the Border Affairs Department of the Royal Thai Army held a meeting on April 20, 2025, to discuss solutions. EPCO also presented March water testing results showing elevated arsenic levels in the Kok River and outlined plans for continued monitoring of river water and sediments. Military authorities pledged to send a diplomatic letter to Myanmar seeking cooperation in addressing the pollution at its source.
On the same day, Tuenjai Deetes, former senator and founder of the Hill Area and Community Development Foundation (HADF), visited Pa Tai village in Mae Ai district, Chiang Mai — an area devastated by floods and mudslides last year. Villagers expressed deep anxiety about future floods, especially after learning of the heavy metal contamination.
Tuenjai reported that local residents have been instructed not to use Kok River water for any purpose, drastically altering their way of life. Children can no longer swim, farmers have lost irrigation sources, and livestock cannot safely drink from the river. Businesses relying on tourism have also suffered losses.
“Villagers say relatives across the border in Shan State — in Mong Kok, Mong Sart, and Mong Yon — are aware that massive deforestation and mining for Chinese-backed rubber plantations and mining operations upstream worsened last year’s floods,” Tuenjai said. “If the Thai government coordinated seriously with the Chinese government, it might lead to solutions.”
Tuenjai emphasized that riverside communities are now highly aware of the toxic risks but remain deeply worried about both pollution and future floods. She called for transparent communication from authorities and urgent action to address the root causes.
Dr. Lalita Hanwong, a Myanmar expert and professor at Kasetsart University, said the Kok River contamination highlights complex transnational issues — with Chinese investments playing a key role. She criticized some Thai authorities for avoiding direct mention of Chinese involvement.
“Everyone in the area knows which companies are responsible. It’s no secret,” Lalita said. “We’ve seen similar disregard for environmental governance in the Mekong River case.”
Lalita stressed that Thailand must abandon overly cautious diplomacy and prioritize citizen safety over political sensitivities. “If the Thai government remains passive while its citizens lose access to safe water — a basic human right — it represents a failure of governance.”
She noted that after Myanmar’s 2021 coup, the United Wa State Army (UWSA) expanded mining concessions in its territory, where many Chinese companies operate.
“The Thai government must engage directly with China to pressure Chinese mining companies at the headwaters of the Kok and Sai Rivers,” Lalita urged. “At this point, it’s no longer a question of ‘whether’ Chinese companies are involved. It’s obvious.”
See original Thai articles, https://transbordernews.in.th/home/?p=42185, and https://transbordernews.in.th/home/?p=42201
