Vertical profile of 137Cs in the Mumbai harbour bay coastal sediments

The vertical profile of 137Cs was investigated by collecting core sediments from different locations in the Mumbai Harbour Bay. 137Cs has a simple marine geochemical behaviour. Trombay shore, which is dominated by suspended silt particles and rich in clay mineral composition concentrates higher 137Cs activity. Across the shore at Elephanta and Vashi shore containing more of sand particles, showed lesser accumulation of the activity in the sediments with respect to water activity levels. A differential distribution with depth was observed in the sediments, which is attributed to radioactive decay, annual release rate and desorption of 137Cs from the sediments into the water column. This also reflects the changing balance between erosion due to tidal effect and deposition associated with siltation. (author)