Spatial distribution of radium in coastal marine waters of Tamil Nadu

An investigation on the distribution of radium activity levels in the entire south eastern coast of Tamil Nadu, India, from Chennai to Kanyakumari was carried out. Insitu preconcentration technique was adopted by passing 1,000 L of seawater through MnO2 impregnated cartridge filters at all the locations. In the coastal waters, 226Ra and 228Ra concentration was observed to be in the range of 1 to 1.81 and 3.1 to 7.5 mBq/L, respectively with an average of 1.52 and 4.53 mBq/L. respectively, while the sediment samples showed 226Ra activity levels from 8.1 to 129.0 Bq/kg and 228Ra varied from 14.7 to 430.01 Bq/kg. The Kd values for 226Ra was observed to be from 5.3E03 to 3.5E05 L/kg and for 228Ra it was in the range of 2.3E03 to 5.9E04. It was observed that the concentration of 228Ra was more than 226Ra in all the locations. The spatial distribution of the activity with respect to location is discussed in the paper. The radioactive database obtained, represents reference values for coastal environment of Tamil Nadu. (author)