Arsenic in Salween River 55 times above safe levels, study warns

The quality of the water in the Salween River, along the Thai-Myanmar border in Mae Hong Son province, is below standard and contains excessive amounts of heavy metals, such as arsenic, lead and mercury, according to findings by the Faculty of Science at Chiang Mai University.

The Interim Executive Council (IEC) of Karenni State revealed at a recent press conference that an IEC team collected water, soil and plant samples from the river basin in Sob Moei district of Mae Hong Son and from areas in the Karenni and Karen states of Myanmar last December.

The IEC team then delivered the samples to team of researchers led by Assistant Professor Wan Viriya,

The findings of testing show excessive amounts of arsenic especially, which was measured at 0.55mg/L against the standard level of 0.01mg/L. Or 55 times higher than the standard level.

The high content of heavy metals in the river is blamed on unregulated lead mining operations and the widespread ore dressing (processing) carried out by Karenni civilians in the Karenni state.

The water used in processing the ores is discharged directly into the river without treatment.

Assistant Professor Wan said that the hazardous substances were found in sediments washed downstream during heavying flooding. He expressed concern that more contamination will follow if flooding is repeated.