Mekong River's Arsenic Shock: Danger Found

Recent tests conducted in March by Thai authorities have revealed dangerous levels of arsenic contamination in sediment from the Mekong River's mainstream. This marks the first recorded instance of arsenic detection in the river's main channel. Sediment samples from three monitoring stations showed concentrations ranging from 73 to 296 milligrams per kilogram, far surpassing the 33 mg/kg threshold deemed dangerous by Thailand's Pollution Control Department.

The contamination has also been found in three tributaries: the Kok, Sai, and Ruak rivers, with readings between below 33 mg/kg and 57 mg/kg. Heavy metal pollution in the Mekong Basin is widely attributed to unregulated mining activities further upstream in Myanmar. Analysis identified hundreds of unregulated mines, including rare earth mines, with many having opened recently.

This finding elevates concerns, as the contamination now affects the river channel that transports water and sediment across borders. The Mekong Basin supports over 50 million people and a rich biodiversity, including critically endangered species. The Pollution Control Department is monitoring the situation to determine if the arsenic readings persist, as the contamination appears to be spreading and is now considered a mainstream river problem affecting multiple countries.