US Think Tank Sounds Alarm on Toxic Chemical Leaks from Illegal Mining Operations
Mining News | 2025-11-24 12:34:17
The contamination pattern in samples from the Kok River shows the presence of arsenic alongside heavy rare earths such as dysprosium and terbium.
By Paul Ploumis
SEATTLE (Scrap Monster): A newly released investigative report by the Washington-based Stimson Center has issued a stark warning about the growing environmental crisis caused by unregulated mining across mainland Southeast Asia. According to the study, thousands of mining sites—many of them illegal—are leaching hazardous substances including mercury and cyanide into vital river networks depended upon by millions of residents.
The landmark research, the first extensive assessment of its kind, examined more than 2,400 mines across the region using advanced satellite imaging technology. The analysis identified 366 alluvial mining zones, 359 heap-leach operations and 77 rare-earth extraction sites situated around waterways feeding into the Mekong River Basin. Most alluvial sites were linked to gold extraction, while heap-leach facilities were tied to the mining of gold, nickel, copper and manganese.
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Researchers highlighted that rare-earth mining activities are discharging a range of highly toxic chemicals such as ammonium sulfate, sodium cyanide, mercury and other dangerous compounds directly into rivers. These pollutants pose severe long-term health threats to the millions of people who rely on the Mekong and its tributaries for drinking water, agriculture and fishing.
The report underscores that river systems branching from the Mekong, Salween, and Irrawaddy rivers are likely already suffering from significant contamination. Sample analyses from the Kok River revealed worrying levels of arsenic and heavy rare-earth elements including terbium and dysprosium—substances associated with cancer, neurological damage and organ failure.
Previous scientific warnings have cautioned that pollution levels could escalate sharply if unregulated mining is allowed to continue unchecked. Environmental experts are calling for urgent action from regional governments to enforce stricter regulations and restore affected ecosystems before irreversible damage occurs.
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Frequently Asked Questions
- What did the Stimson Center report uncover about mining in Southeast Asia?
The report revealed that more than 2,400 mostly unregulated mines in the region are releasing highly toxic chemicals, including cyanide and mercury, into major river systems.
- Which rivers are most affected by the contamination?
The study found that waterways connected to the Mekong, Salween and Irrawaddy rivers are likely experiencing severe pollution caused by mining runoff.
- What types of mining operations were analyzed?
The research examined alluvial gold mining sites, heap-leach operations for metals such as gold, copper, nickel and manganese, and rare-earth mining sites.
