"Dangerous arsenic levels detected in Thailand’s Mekong mainstream for first time", 8 May 2026

… Thai authorities have found what they described as dangerous levels of arsenic contamination in sediment from the Mekong River and three of its tributaries in the northern provinces of Chiang Mai and Chiang Rai.

Heavy metal pollution has been reported from key tributaries of the Mekong for more than a year now, but the tests conducted in March by Thailand’s Pollution Control Department mark the first time that arsenic contamination has been detected on the mainstream of the Mekong, a vital transboundary river that supports thousands of plant and wildlife species and the livelihoods of millions of people…

Arsenic levels in sediment taken from various points along the Kok, Sai and Ruak rivers, key tributaries of the Mekong, all ranged from below the 33 mg/kg safe limit up to 57 mg/kg, the Pollution Control Department said via its official Facebook page, noting the contamination appears to be spreading through the river system.

Thailand’s Pollution Control Department posted results of the sediment tests to their official Facebook page on April 10, 2026. Image sourced from the Pollution Control Department’s Facebook.

… More than 50 million people across the Lower Mekong River Basin rely on the river for water, fish and livelihoods, but the Mekong has also long been a biodiversity hotspot, hosting some 20,000 species of plants, …

… Rare earth elements are crucial to military, aerospace and automobile industries globally, as well as fueling the green energy transition. But they’re typically extracted using an especially ecologically destructive form of mining…

The level of environmental damage caused by this form of mining, known as in situ mining, saw China, the world’s leading producer and processor of rare earths, place heavy restrictions on its domestic mines back in 2009, while quietly moving mining operations into other jurisdictions, like Myanmar, Mongolia and Malawi…