Impact of Tropical Ecosystem on the Migrational Behavior of K-40, Cs-137, Th-232 U-238 in Perennial Plants

A comprehensive study was conducted to determine the soil to plant transfer factor (TFS–P) of K-40, Cs-137, Th-232 and U-238 in perennial plants from accessible areas of Mumbai, using high-resolution γ spectrometry. A total of 50 soil and 150 plants samples were collected from all over the Mumbai region where lithology is dominated by basaltic rocks. The mean concentration values for K-40, Cs-137, Th-232 and U-238 in soil was 170.06 ± 65.36, 5.19 ± 1.20, 25.72 ± 6.262 and 10.21 ± 2.82 Bq kg−1 respectively, whereas in case of plants the mean concentration values were determined to be 181.82 ± 18.50, 0.44 ± 0.14, 0.84 ± 0.19 and 0.79 ± 0.22 Bq kg−1 respectively. The mean activity ratio of Th-232/U-238 in plants is 1.06 while in soil the ratio is 2.5. The soil to plant transfer factor (TFS–P) calculated for K-40, Cs-137, U-238 and Th-232 are 1.05, 0.076, 0.071 and 0.031 respectively. Higher value of TFS–P for K-40, which is an integral part of stable potassium clearly indicates the physiological need of stable potassium, for maintaining the different biological mechanisms of perennial plants under tropical conditions.