ABSTRACT
Arsenic (As) contamination in the Brahmaputra basin has been extensively studied, with reports of contamination in Yarlung Tsangpo, the Brahmaputra floodplain, and the large delta in Bangladesh. However, the presence of arsenic in the eastern Himalayan region is still not fully understood. In this study, we analyzed the mineralogical and elemental composition of sediment samples and found the presence of As-bearing minerals, particularly realgar and orpiment. The mineralogical composition further corroborated the elemental composition, with the presence of As, Fe, and S in the sediment samples. These findings highlight the pres-ence of arsenic in the remote upper Siang basin in the eastern Himalaya, thereby providing important insights into the trail of As contamination from Tibet to Bangladesh.
