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The study attempts to look into the morphological characteristics, elemental composition, contamination, source contributions, and associated health risks in household dust of Napaam, a rural region in the Brahmaputra flood plain in North East India. Morphological evidence suggests that most of the house dust particles were sourced from vehicle abrasion and soil. Three contamination indices-enrichment factor (EF), index of geo-accumulation (I

Spatial and temporal variation in the major ion composition of the waters in the Brahmaputra River has been measured to understand chemical weathering and the factors controlling these processes. Samples were collected from the Brahmaputra mainstream at five stations Pasighat, Dibrugarh, Tezpur, Guwahati and Dhubri during monsoon and post monsoon seasons. The total dissolved solids in the waters of the Brahmaputra system ranges between 62.5 and 192.5 mgl-1. The (Total dissolved solids) TDS of the Brahmaputra measured in this study are less than the values reported by earlier workers. Gibbs plot was plotted to investigate the dominant process controlling the water chemistry of the Brahmaputra. The plots of TDS vs. (Na + K)/(Ca + Na + K) and TDS vs. indicate that rock weathering is the main process controlling the chemistry of water in the Brahmaputra River. Factor analysis was done to study the factors controlling the water chemistry of the Brahmaputra.

Carbon is transported from the land to the oceans via rivers and groundwater. The transfer of organic matter from the land to the oceans via fluvial systems is a key link in the global carbon cycle. Rivers also provide a key link in the geological scale carbon cycle. Nevertheless, an appreciation of their roles is yet to be made. Even when their roles are included, data are drawn only from selected large rivers, often neglecting the small mountainous rivers. Previous studies have demonstrated that, the tropic rivers, especially located in Asian region play crucial role in regulating the global carbon budgets. Superimposed on the natural sources and fluxes, the anthropogenically-induced fluxes, primarily emanating from reduced sediment and discharge (as a result of constructions of dams and reservoirs), and enhanced detrital organic matter (as a result of increased surface flow due to land use change) introduce perturbations.