Abstract Plants can transfer radioactivity into human nutrient cycle and ecosystem directly by vegetable food products and indirectly by animal food products. Also their role is important in absorption of environmental radioactive pollutants. Plant radioactivity is different based on soil and stone kind and geographical situation. Then subtle plant recognition of each environment can prepare valuable information for researchers. In this work the natural and artificial radioactivity concentrations of 226 Ra, 232 Th, 40 K and 137 Cs in 8 medicinal and edible plant species including: Saliva nemorsa L., Triticum aestivum L., Peganum harmala L., Vitis vinifera cv. Shirazi, Medicago sativa L., Gondelia tournefortii L., Descorainia sophia (L.) Webb et Berth and Achillea vermicularis Trin. were determined using HPGe gamma ray spectrometry system. Samples were collected from Bagh-e-Baraftab Village, Shazand in Markazi Province, Iran. Measured radioactivity concentrations for 137 Cs, 40 K, 232 Th and 226 Ra obtained from MDA to 1.02±0.35, from MDA to (2.75±0.01) ×10 , from MDA to 7.79±1.40 and from 2.27±0.45 to 7.43±0.60 in Bq/kg respectively. Soil -to -plant transfer factor (TF) calculated for all samples. Results showed Peganum harmala had the maximum TF (3.17 for 40 K) and Vitis vinifera cv. Shirazi was minimum (9.62×10 -2 for 137 C). Internal and external hazard indices were calculated for all samples that were less than unity. These results show that consumption of the studied plants would impose no health consequences to the consumers. 3
