Biomonitoring of 137Cs fall-out in Kudankulam coastal waters, Gulf of Mannar, India

Concentration of fall-out ¹³⁷Cs activity was monitored for a period of 3 years in coastline surface, near-shore surface and bottom waters of Kudankulam coast where a mega nuclear power station is being set up. Activity of ¹³⁷Cs was estimated by HPGe gamma spectrometry after chemical processing with AMP (ammonium molybdophosphate). The total ¹³⁷Cs concentration ranged from 1.2 to 1.6 mBq/L in coastline surface waters and between 0.75 and 1.4 mBq/L in near-shore surface and bottom waters. The data set followed a log-normal distribution. An insignificant relationship between ¹³⁷Cs and salinity, temperature and pH was noted. No yearly variation and no variation between surface and bottom waters were observed (p > 0.05) in the concentration of ¹³⁷Cs. The ¹³⁷Cs activity between seasons was found to be significantly different (p < 0.05).