210Po and 210Pb in medicinal plants in the region of Karnataka, Southern India

The activity concentrations of naturally occurring radionuclides 210Po and 210Pb were estimated in some selected medicinal plants and soil samples of coastal Karnataka in India. The mean activity concentrations of 210Po and 210Pb varied in the range of 4.7-42.9 Bq kg−1 (dry weight) and 36.1-124 Bq kg−1 (dry weight) in the soil samples, and 3.3-63.7 Bq kg−1 (dry weight) and 12.0-406 Bq kg−1 (dry weight), in the medicinal plant samples, respectively. The plants, Ocimum sanctum L. and Plectranthus amboinicus (Lour.) Spreng had significantly higher activity concentrations of 210Po and 210Pb than other species sampled. In spite of disequilibrium between them, these two radionuclides were well correlated in both soil and medicinal plants.