Prelims: Current events of national and international importance | Environment
Why in News?
Recently, Independent testing in September 2025 revealed alarming levels of arsenic contamination in the Salween River.
Salween River
- Location – Originates in Tibet, flows through China and Myanmar, forms part of the Myanmar–Thailand border, and drains into the Andaman Sea.
- Type – Transboundary free‑flowing river system.
- Length – 3,300 km; Asia’s longest undammed river.
- Supports fisheries, irrigation, and ethnic Karen and Karenni communities; a biodiversity hotspot.
Findings of the Recent Study
- Contaminants – Arsenic, cadmium, cyanide, mercury linked to rare earth and gold mining.
- Levels – Arsenic found 5 times over WHO limits are 0.01 mg/l arsenic in water; tributaries recorded up to 0.554 mg/l.
- In situ leaching pumps chemicals underground, dissolving minerals but releasing toxins.
- Impacts
- Fish with sores and deformities; benthic organisms harmed by toxic sediments.
- Thai rice shipment to Australia was rejected in Oct 2025 due to arsenic contamination.
- Karen and Karenni villagers face poor information flow, limited alternatives, and reliance on contaminated water/fish.
- Pollution flows across the Myanmar–Thailand border, raising diplomatic and environmental governance concerns.
Reference
Mongabay | Salween River
