Estimation of 226Ra and U(Nat) in sediment off Mumbai coast

Bottom sediment in a marine system is formed from organic and inorganic particles which settle from water of aquatic media. The sediment compartment is the receptor of radionuclides and it indicates the impact of pollution. Radioactive materials like Ra and U are normal constituents of earths crust. The present study was done to estimate 226Ra and U(Nat) from various locations in sediment off Mumbai coast. The levels of 226Ra in sediments of Mumbai coast has been observed to be between 3.8 to 26.0 Bq/kg with a mean averaged value of 13.3 Bq/kg which is similar to the sediment at Bay of Bengal (13.9 to 25.9 Bq/kg), Indian Ocean (13.8 Bq/kg), Arabian Sea (16.9 to 31.7 Bq/kg), Egyptian Red sea coast (27.4 Bq/kg). Uranium content in sediment was found to be in the range of 16.3 to 56.3 Bq/kg with an averaged mean of 32.2 Bq/kg. It is observed that, uranium concentration is higher than radium concentration in sediment. This may be attributed to the relatively higher mobility of radium as compared to uranium in an aquatic environment