Natural radioactivity determination in samples of Peperomia pellucida commonly used as a medicinal herb

The concentration of (238)U, (232)Th, (230)Th, (226)Ra, (228)Ra and (210)Pb were determined in samples of Peperomia pellucida and in the surrounding soil, by alpha spectrometry and gross alpha and beta counting. The radionuclide activity concentrations ranged from 4.3 to 38 Bq kg(-1), 1.7-124 Bq kg(-1), 2.1-38 Bq kg(-1), 8.5-37 Bq kg(-1), 3.2-46 Bq kg(-1), 39-93 Bq kg(-1), respectively. In the plant extractions and infusions as used for consumption, the mean recoveries were from 23% to 60% in maceration and 24-75% in infusion.