by Paskorn Jumlongrach
Transborder News- The discovery of a gold mine along the Kok River and large-scale land clearing in the town of Tachileik, southern Shan State, Myanmar, just a few kilometers from the Thai border near Mae Ai district, coincides with previous findings of gold mining at the source of the Sai River. This helps explain the abnormal discoloration of the water in the Kok and Sai Rivers.
During the dry season, the waters of the Kok and Sai Rivers are typically clear. However, in recent years, the Sai River has become persistently murky, and now the Kok River shares the same condition. Since the major flood in September 2024, the water in these rivers has never regained its clarity.
Public concern is growing, as the murkiness of the rivers may be linked to gold mining operations in the border region of Shan State. Villagers report that the United Wa State Army has granted Chinese companies permission to operate these mines. This suggests a significant ecological disruption to the Kok and Sai River basins.
Questions regarding water safety have been raised, despite the governors of Chiang Mai and Chiang Rai ordering the Pollution Control Department and other relevant agencies to assess water quality. However, conclusive results have yet to be released. More importantly, regardless of the findings, the most pressing question remains: how do downstream Thai communities feel about gold mines operating at the headwaters of the Kok and Sai Rivers?
“First, we need to understand what to test for. We must examine the sources of pollution, its pathways, the extent of contamination, and potential exposure risks,” said Somporn Phengkham, an independent researcher and founder-director of the Community Health Impact Assessment Platform (CHIA Platform). He outlined the process of testing for contaminants in water and soil that could affect local communities and ecosystems.
“In the case of the Kok and Sai Rivers, we observe unusual turbidity. Our hypothesis is that sediment from the headwaters in Shan State is being washed downstream. If this results from gold mining, we must assess the risks. Before testing, we need to determine whether the gold veins in the area contain arsenic. If gold processing is involved, mercury and cyanide may be used—these would be key indicators for our tests,” said Somporn, who has extensive experience investigating mining-related toxic contamination, particularly in the Klity Creek case in Kanchanaburi. This expertise helps define the key concerns for the Kok and Sai Rivers.
“If we do not define our research objectives correctly, we might end up conducting general water quality tests—measuring turbidity or oxygen levels—but in this case, we must focus on pollution linked to gold mining. Mercury contamination, for example, accumulates in fish rather than being directly measurable in soil or water. It moves through the food chain: from plankton to shrimp and fish that consume contaminated sediment, then up to larger predatory fish. Testing large fish would provide better insights than testing the water directly, as mercury contamination is not always detectable in water samples.”
Somporn explained that mercury is found in sediment and accumulates in the food chain. While direct exposure from water may be minimal, ingestion of contaminated fish results in bioaccumulation, magnifying toxicity thousands of times. Mercury poisoning is a globally recognized hazard, leading to the United Nations’ Minamata Convention, which aims to phase out mercury use. Without proper testing methods, contamination may go undetected.
“We need to establish the right benchmarks to determine whether the Kok and Sai Rivers are polluted by mining activities. Cyanide, for example, degrades quickly in sunlight. If gold mines upstream use cyanide, it is unlikely to be present in significant amounts downstream. However, if it is detected, it would indicate dangerously high concentrations. Cyanide exposure is more of a concern for residents living near the mines. For Thai communities downstream, arsenic is the primary threat. Gold mining often involves pyrite, which releases arsenic as a byproduct, contaminating soil and water.”
“When testing for contamination from mining activities, it is best to analyze mercury accumulation in fish or hair samples from people who regularly consume fish from these rivers. Arsenic, on the other hand, is best detected in soil and water samples.”
Regarding immediate solutions for the murky waters in the Kok and Sai Rivers, Somporn suggests that water samples should be collected and tested immediately. Once results are available, they should be communicated to local communities. Additionally, if river water is used for public water supply, arsenic treatment processes must be implemented.
“During the Songkran festival, if the water is contaminated, people may experience skin irritation or rashes. Those with sensitive skin may develop blisters.”
Somporn emphasized that if pollution sources remain unaddressed, preventive measures must be taken. Unlike naturally occurring soil and water, sediment from mining operations may contain hazardous chemicals. When the Pollution Control Department collects water samples, it is crucial to clarify what is being tested and why. Proper hypotheses must be established before conducting tests, considering relevant industrial activities and potential pollutants.
Regarding last year’s massive mudflow that triggered a “mud tsunami” in Chiang Rai and Mae Sai, Somporn noted that contamination risks should be assessed. If the mud originated from mining activities, it could carry toxic chemicals. Effective risk communication is also essential. Proper analysis must be conducted to identify specific pollutants and determine appropriate testing methods.
“For example, in Mae Sai, if we confirm that the mud originates from gold mining, hair sample testing from women who regularly consume fish from these rivers would help establish a direct link. This evidence could then be used to advocate for systematic monitoring and discussions with Myanmar authorities to address the issue collaboratively.”
Somporn pointed out that, in principle, mining operations should not be located in headwater areas. Environmental laws typically designate headwaters as protected zones. However, for transboundary rivers, ASEAN lacks a framework for cross-border environmental and health impact assessments. Myanmar’s regulatory standards are uncertain, adding to the complexity of the issue. Given the current political instability in Myanmar, enforcement of its environmental laws is questionable. The most viable approach for Thailand is to gather clear domestic data and use it as a basis for negotiations with relevant authorities, emphasizing health concerns as a priority.
Current water quality assessments often provide only general results, concluding that conditions are “normal.” Somporn challenges this notion: “What does ‘normal’ mean?”
“‘Normal’ could refer to basic parameters such as oxygen levels and turbidity. However, if specific pollutants are not tested for, their absence cannot be assumed. The real concern is for local communities relying on these rivers for drinking water, agriculture, and fishing. If contamination goes unchecked, long-term health consequences could emerge in five to ten years, making intervention more difficult.”
Somporn highlighted that pollution-related health risks are complex and that knowledge about contaminants remains limited. For example, the Hongsa lignite power plant, located near Thailand’s Nan Province, emits heavy metals that may bind to PM2.5 particles, further complicating pollution management.
“Our understanding of pollution is still developing. Testing facilities are limited, and analysis requires specialized expertise. Even if contamination is confirmed, the question remains: how will it be addressed?”
“Cross-border pollution adds another layer of complexity. Which country’s laws should apply? Thailand’s environmental regulations cannot be enforced in Myanmar, yet downstream Thai communities bear the impact. What role should ASEAN or regional organizations play in managing such issues? At present, there are no established international mechanisms.”
Somporn concluded by pointing out that transboundary environmental impacts, such as those from Mekong River dams and PM2.5 pollution, are often downplayed by authorities, who prioritize economic considerations. “For example, northern Thai provinces are reluctant to declare disaster zones due to concerns over tourism. This approach suppresses the problem instead of solving it. Such decisions delay effective action and worsen long-term consequences.”
See original Thai article, https://transbordernews.in.th/home/?p=41826
