Disequilibrium of uranium series radionuclides in soil and plants of South India

Dose and transfer factor ofn 40K in medicinal plants

The presence of naturally occurring radionuclides is common in all living and non-living frameworks, which are part of our environment. The activity concentration of 40K radionuclide was estimated using gamma spectrometry in some medicinal plants and transfer factors (TF), and Average Annual Committed Effective Dose (AACED) was evaluated. The standard methods were followed in the process of sample collection and processing. The mean activity concentrations of 40K were 223 and 1330 Bq kg-1 in soil and medicinal plants, respectively. The mean TF and AACED were found to be 6.5 and 8.2 μ Sv y-1, respectively. Higher activity concentration was observed in some medicinal plants due to the selective and preferential uptake of this radionuclide depending on their medicinal utility. The study may help to form the database and safety regulations connected with 40K activity in medicinal plants.

210PO IN SOIL AND TOBACCO LEAVES IN QUANG XUONG, VIETNAM AND ESTIMATION OF ANNUAL EFFECTIVE DOSE TO SMOKERS

210Po is the main radiotoxic chemical in tobacco smoke and one of the primary causes of lung cancer. Investigating 210Po concentration in tobacco is important in estimating the annual effective dose (AED) due to smoking. In this study, the 210Po concentrations in tobacco leaves and soil in Quang Xuong, Vietnam were measured using a high-resolution passivated and implanted planar silicon detector. Based on these data the AEDs to smokers were estimated. The 210Po activity concentration in tobacco varied significantly from 28.7 to 254.0 mBq g-1, whereas its variation in soil was insignificant. The AED due to smoking fresh tobacco leaves in Vietnam (average 565 μSv y-1) was significantly higher than the values reported for other countries (36-361 μSv y-1).

Study on Trace Elements Concentration in Medicinal Plants Using EDXRF Technique

Ten medicinal plants used as ingredients of folklore and Ayurvedic medicine belonging to the Malnad Kerala region of South India, were analysed for concentrations of trace elements Fe, Cr, Mn, Co, Ni, Cu, Zn, As, and Pb using the Energy Dispersive X-ray Fluorescence (EDXRF) technique. The soil from the root area of these medicinal plants was also analysed, and the soil to plant transfer factor (TF) of the elements was estimated. Iron (Fe) recorded higher concentration than the other trace elements estimated in the medicinal plants, followed by manganese (Mn) and zinc (Zn). The mean TF was found to be highest for Zn. Plectranthus amboinicus (Lour.) Spreng recorded the maximum value of TF for Zn. Most of the essential elements were found to be present in Centella asiatica (L.) Urban and indicated its medicinal importance. The data obtained in the present investigation may add up to the trace elemental database of medicinal plants in the world.