Mae Kok River Pollution Seminar at Chulalongkorn University, 28 October 2026

The Nelson Mandela Centre of Chulalongkorn University, in collaboration with the Hanns Seidel Foundation Thailand, is holding a public seminar on Wednesday, 28 October 2026 on transboundary water pollution in the Mae Kok River Basin. The seminar, titled “Transboundary Water Pollution in the Mae Kok River Basin: Governance, Community Health, and Business Responsibility,” looks at the issue through three lenses: how pollution is governed, what it means for community health, and where businesses fit.

Event details

• Date: Wednesday, 28 October 2026
• Time: 13:30–15:30 (registration opens at 13:00)
• Venue: Political Science Alumni Association Meeting Room, 12th Floor, Kasem Udyanin Building, Faculty of Political Science, Chulalongkorn University
• Registration: https://forms.gle/Asv9L2pGfbTJAXYTA

The panel

The panel is moderated by Assoc. Prof. Dr. Kasira Cheeppensook, Deputy Director of the Nelson Mandela Centre, Faculty of Political Science, Chulalongkorn University. The three presentations are:

1. “Adaptive Governance of Chemical Pollution in the Kok River” by Assoc. Prof. Dr. Witchuda Srang-iam, Faculty of Political Science and Public Administration, Chiang Mai University.
2. “Water Pollution from Mae Kok – Mae Sai’s Community Health Impact Assessment” by Khun Somporn Pengkam, Director of the Community-led Impact Assessment Institute.
3. “Transboundary Water Pollution and Business Responsibility” by Assoc. Prof. Dr. Pawat Satayanurug, Director of the Law and Development Research Centre, Chulalongkorn University.

Background: the Kok River contamination

The Kok River flows about 300 km from Tachileik in Myanmar’s Shan State into Mae Ai district in Chiang Mai, then reaches the Mekong via the Sai and Ruak rivers. Contamination in the river began in 2025. Heavy metals have since been found in the water and fish of the Kok, Sai, Ruak and Salween rivers, and in Mekong sediment. Analysts link the spread to unregulated mining in Myanmar, notably in areas held by ethnic armed groups.

In April 2025, Chiang Rai residents were warned to avoid contact with the Kok River just before Songkran, after tests found elevated arsenic. Thai university researchers have since recorded arsenic readings in the Kok River basin of more than twice Thailand’s national standard of 0.01 mg per litre. A Mae Fah Luang University paper released in February reported arsenic accumulation in people living along the river. Thailand’s Pollution Control Department said in March that most heavy metals remained within acceptable limits, although arsenic still exceeded standards in parts of the Kok, Sai and Mekong rivers.

The social effects are wide. Fear of contamination has hurt tourism and fishing in Chiang Rai. Residents in Mae Sai district have long reported discoloured water. An estimated 1,500 people rallied in Chiang Rai in June 2025, urging the Thai government and China to pressure the mining operators in Myanmar to stop polluting their rivers. A spokesperson for the Thai Prime Minister’s Office said the government has set up a working group to monitor the contamination and has been coordinating with other countries.

Why the seminar matters

Pollution that starts across a border is difficult to govern, because no single government controls the source. The seminar’s three themes reflect that: adaptive governance for managing chemical pollution when conditions keep changing, community-led health assessment for people living along the river, and the legal and ethical duties of businesses whose supply chains may be linked to mining. Findings from Mae Sai residents in particular could add local health evidence to a debate that has so far leaned on water and sediment tests.

Conclusion

The seminar brings academics, community researchers and legal experts together at a time when the Kok River’s contamination remains unresolved. Anyone interested can attend this afternoon, though registration should be completed through the official form beforehand. The discussion is likely to be useful for researchers, policymakers, journalists and business representatives who follow transboundary water issues in the Mekong region.

Source: Nelson Mandela Centre, Chulalongkorn University, and Hanns Seidel Foundation Thailand, seminar announcement; Mongabay, 2025–2026; Nation Thailand, 2026.