Bioaccumulation of 210Pb in the Kaveri River ecosystem, India

Data on the concentrations of 210Pb in water, sediment and biota (plankton, weed, snail, bivalve, prawn and fish) of the Kaveri River ecosystem at Tiruchirappalli in South India are presented. The highest level of 210Pb activity was observed in the sediment (15.5 Bq kg-1 dry) and the lowest activity in water (2.7 mBq l-1). The root of the aquatic weed, Eichhornia crassipes, showed a higher activity (1.17 Bq kg-1 wet) than its shoot (0.22 Bq kg-1 wet). Among the biotic components, the shells and bones of animals accumulated higher 210Pb than their tissues and muscle. Among animals, the freshwater mussel, Lamellidens marginalis was identified to accumulate more 210Pb in its soft tissues (0.79 Bq kg-1 wet) and shell (6.55 Bq kg-1 wet) than prawns (muscle 0.65 Bq kg-1 wet; exoskeleton: 1.06 Bq kg-1) wet and fish (muscle: 0.24 Bq kg-1 wet; bone: 1.37 Bq kg-1 wet). The concentration factors (CFs) of 210Pb in biotic components ranged from ∼ 101 to ∼ 103 with higher CFs observed for shells and bones. It is shown that 210Pb undergoes a seasonal variation in surface deposition with minimum values in summer and maximum values in winter. The significance of the results of 210Pb in the abiotic and biotic environment of Kaveri River is discussed. (Author)