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Background: The presence of radionuclides in the soil, measures need to be taken to minimize the radiation dose to humans. It is mostly gamma-emitting radionuclides that contribute to the radiation dose in long term behavior of these radionuclides in soil may determine the extent to which such countermeasures need to be applied.

Materials and Methods: The activity concentration of these radionuclides in the soil samples that collected from the Longwood forest at western Ghats have been analyzed using Gamma spectrometry.

Results: The mean activities of ²³⁸U, ²³²Th and ⁴⁰K were observed 26.261Bq/kg, 53.614 Bq/kg, 204.084 Bq/kg, dry weight, respectively. The average value of dose rate was calculated 55.48 nGy/h by applying the conversion factor where as the environmental dosimeter shows the absorbed dose rate at 1m high is 96.96 nGy/h.

Conclusion: It was observed that the activity concentration of primordial radionuclides and the gamma dose rate measurements by ERD and from soil is relatively higher than world average.

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Introduction: Investigation on the natural radionuclides 238U, 232Th, 40K and natural fallout radionuclide 210Po in the prominent plants species of Western Ghats tropical forest near Kotagiri have been carried out as a part of baseline background radiation studies in the forest environment. Materials and Methods: The prominent plants species of the region Evodia roxburghiana and Eleaocarpus oblangus were chosen and concentrations of 238U, 232Th, 40K and 210Po were measured by employing gamma ray spectrometer and alpha counter. Results: The radioactivity concentrations in plants and soils reflect the impact of the existence of igneous nature of rock in the area of study. Concentration ratios (CR) of these radionuclides, between plants and underlying soil, have been studied and results shows that the concentration ratios (CR) seem to be depend on radionuclides in soil. Conclusion: From careful analysis of the results, these Plants could be used as an indicator to monitor these radionuclides.

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Background: A study on the migration characteristics of 238U, 210Po, 232Th and 40K within the soil to the wild plants in the Western Ghats were carried out. Materials and Methods: Concentrations of these radionuclides were measured in different depths of soil and from different species by employing gamma ray spectrometer and alpha counter. Results: The activity concentration of these radionuclides varied faintly within the soil but widely varied within the plant and between the species. Conclusion: The CR (Concentration ratio) showed wide variation in different species, while a few species of wild plants such as Evodia roxburghiana, Eleaocarpus oblangus and Glochidion neilgherense indicated preferential uptake of these radionuclides. Iran. J. Radiat. Res., 2008 6 (1): 7-12

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Background: Investigation on the natural radionuclides 238U, 232Th, 40K and natural fallout radionuclide 210Po in the prominent plants species of Western Ghats tropical forest near Kotagiri have been carried out as a part of baseline background radiation studies in the forest environment. Materials and Methods: The prominent plants species of the region Evodia roxburghiana and Eleaocarpus oblangus were chosen and concentrations of 238U, 232Th, 40K and 210Po were measured by employing gamma ray spectrometer and alpha counter. Results: The radioactivity concentrations in plants and soils reflect the impact of the existence of igneous nature of rock in the area of study. Concentration ratios (CR) of these radionuclides, between plants and underlying soil, have been studied and results shows that the concentration ratios (CR) seem to be depend on radionuclides in soil. Conclusion: From careful analysis of the results, these plants could be used as an indicator to monitor these radonuclides.