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Groundwater (open well and bore well) samples from various locationsof coastal Karnataka and Kaiga have been investigated for their 222Rn concentrations by emanometry method. The concentration of 222Rn in open well water was found to vary in the range 0.14-25.4 Bq L-1 with a median value of 3.74 Bq L-1 and that in bore well water in the range of 0.22-197.0 Bq L-1 with a median value of 5.75 Bq L-1. From the measured concentrations the effective doses for the population of the region were estimated. The effective dose was found to vary from 0.09 muSv y-1 to 204.2 muSv y-1 for open well water consumers and from 0.2 muSv y-1 to 1586.9 muSv y-1 for bore well water consumers. The results of the present study arealso compared with the literature values and discussed. [ABSTRACT FROM AUTHOR]

This paper deals with the distribution and activity intake of 210Po and 210Pb in food, diet, and potable water samples of the Goa region and the estimated committed effective dose due to ingestion of these radionuclides. The activity concentrations of 210Po and 210Pb were determined in about 30 foodand diet samples from different places of Goa in order to know the distribution and intake of these radionuclides. The activity concentration of 210Po in fish and prawn samples were significantlyhigher than concentrations found in vegetable and rice samples. Higher concentrations of 210Po and 210Pb were observed in leafy vegetables than in non-leafy vegetables. Among the diet samples the activity concentrations of 210Po and 210Pb in non-vegetarian meal samples were relatively higher than invegetarian meal and breakfast samples. The committed effective dose due to annual intake of 210Po was found to be 94.6 muSv, 49.1 muSv, 10.5 muSv, and 2.2 muSv and that of 210Pb found to be 81.6 muSv, 59.9 muSv, 14.6 muSv, and 2.0 muSv for the ingestionof non-vegetarian meal, vegetarian meal, breakfast, and potable water, respectively. [ABSTRACT FROM AUTHOR]

This paper presents the results of 137Cs activity in soiland vegetation obtained through a carefully planned pre-operational survey for the establishment of baseline data on background radiationlevel and distribution of radionuclides in the environment of Kaiga,in the south west coast of India, where two nuclear power reactors of 235 MWe each are under construction. The vertical profile in soil and the seasonal variation in the activity have been studied. Nine commonly available vegetation species of Kaiga region were analyzed for their 137Cs activity, and the soil-to-plant transfer coefficients were evaluated. Measurements were made by gamma spectrometry method employing a 90 cc HpGe detector and a 3 x 3-inch well type NaI(Tl) detector. Results show significant levels of 137Cs activity in soil samples--ranging from below detection limit (BDL) to 65.4 Bq kg-1. The mean value of activity observed in 0-5 cm soil profiles of Kaiga environs is significantly higher when compared to the reported values for other environs of India. Depth profile studies show that the 137Cs activity decreases with the increasing soil depth, and it is below detection limit for depths more than 25 cm. The mean value of effective dose commitment due to the presence of 137Cs in soil was 167.2 muSv. Vegetation samplesof the region show elevated levels of 137Cs concentration. Epiphytic plants Cymbidium aloifolium (Lo.) Swartz. and Petrobryopsis tumida (Hook.) Dix. have been identified as bio-indicators to monitor the fallout of this radionuclide in the environment of Kaiga. Seasonal variation studies indicate higher fallout of this radionuclide along with rain. [ABSTRACT FROM AUTHOR]

Systematic studies on gamma radiation level and the distribution of natural radionuclides were carried out under a pre-operational surveyfor the establishment of baseline data on background radiation leveland the distribution of radionuclides in the environment of Kaiga, in the south west coast of India, where a nuclear power reactor of 235MWe has just been commissioned. The external gamma absorbed dose rates prevailing in the region were measured using a portable plastic scintillometer. Soil samples from 18 stations were collected from depthintervals of 0-5, 5-10, and 10-25 cm and analyzed for their 226Ra, 232Th, and 40K activity concentrations by gamma spectrometry employing a 90 cc PGT HpGe detector coupled to an EG&G ORTEC 8K multichannel analyzer. The activity of 226Ra was found to vary between 15.5-61.2 Bq kg-1 with a mean value of 31.3 Bq kg-1, that of 232Th variesbetween 11.4-41.9 Bq kg-1 with a mean value of 27.5 Bq kg-1 and of 40K between 78.3-254.8 Bq kg-1 with a mean value of 159.9 Bq kg-1 in 0-5 cm soil profiles of the region. The contributions of 238U, 232Th, and 40K to the total gamma absorbed dose rate were39.9%, 40.7%, and 16.0%, respectively. The gamma absorbed dose rate in air estimated using the results of activity concentration of 226Ra, 232Th, and 40K are found to compare well with that of the direct measurement. The results of the study were compared with the literature values reported for other environs of the country as well as the world, and conclusions are drawn. [ABSTRACT FROM AUTHOR]

Studies on radiation level and radionuclide distribution in the region of Coastal Karnataka, India, were undertaken. The purpose of this study is to provide baseline data on radiation level and radionuclidedistribution in the region for the future assessment of the impact of the nuclear and thermal power stations that are being set up in theregion. Further, this study may reveal information on the transportation of radionuclides in the environment. The external gamma dose rates in air have been measured throughout Coastal Karnataka using a sensitive plastic scintillometer. The measured dose rates include both terrestrial and cosmic ray components. The gamma dose rates in air range from 26 to 174 nGy h-1 with a median value of 74 nGy h-1. The activities of naturally occurring radionuclides in the soil samples of the region were measured using HPGe gamma ray spectrometry, and the resulting doses in air were calculated. The activity of 40K varies from 61.0 to 316.7 Bq kg-1 with a median of 117.5 Bq kg-1; the activity of 226Ra varies from 20.1 to 62.3 Bq kg-1 with a median value 35.0 Bq kg-1 and that of 232Th from 14.3 to 48.6Bq kg-1 with a median value of 29.8 Bq kg-1. The mean absorbed dose rate in air due to naturally occurring radionuclides is found to be 41.5 nGy h-1. In addition to this, the correlations between 226Ra and 40K, 232Th and 40K, and 226Ra and 232Thwere computed from the results of the concentration of these naturally occurring radionuclides. A weak correlation was observed between 226Ra and 40K and between 232Th and 40K while a moderately good correlation was observed between 226Ra and 232Th. The results of these systematic investigations are presented and discussed in this paper. [ABSTRACT FROM AUTHOR]

Groundwater (open well and bore well) samples from various locations of coastal Karnataka and Kaiga have been investigated for their 222Rn concentrations by emanometry method. The concentration of 222Rn in open well water was found to vary in the range 0.14-25.4 Bq L(-1) with a median value of 3.74 Bq L(-1) and that in bore well water in the range of 0.22-197.0 Bq L(-1) with a median value of 5.75 Bq L(-1). From the measured concentrations the effective doses for the population of the region were estimated. The effective dose was found to vary from 0.09 microSv y(-1) to 204.2 microSv y(-1) for open well water consumers and from 0.2 microSv y(-1) to 1586.9 microSv y(-1) for bore well water consumers. The results of the present study are also compared with the literature values and discussed.

This paper deals with the distribution and activity intake of 210Po and 210Pb in food, diet, and potable water samples of the Goa region and the estimated committed effective dose due to ingestion of these radionuclides. The activity concentrations of 210Po and 210Pb were determined in about 30 food and diet samples from different places of Goa in order to know the distribution and intake of these radionuclides. The activity concentration of 210Po in fish and prawn samples were significantly higher than concentrations found in vegetable and rice samples. Higher concentrations of 210Po and 210Pb were observed in leafy vegetables than in non-leafy vegetables. Among the diet samples the activity concentrations of 210Po and 210Pb in non-vegetarian meal samples were relatively higher than in vegetarian meal and breakfast samples. The committed effective dose due to annual intake of 210Po was found to be 94.6 microSv, 49.1 microSv, 10.5 microSv, and 2.2 microSv and that of 210Pb found to be 81.6 microSv, 59.9 microSv, 14.6 microSv, and 2.0 microSv for the ingestion of non-vegetarian meal, vegetarian meal, breakfast, and potable water, respectively.

This paper presents the results of 137Cs activity in soil and vegetation obtained through a carefully planned pre-operational survey for the establishment of baseline data on background radiation level and distribution of radionuclides in the environment of Kaiga, in the south west coast of India, where two nuclear power reactors of 235 MWe each are under construction. The vertical profile in soil and the seasonal variation in the activity have been studied. Nine commonly available vegetation species of Kaiga region were analyzed for their 137Cs activity, and the soil-to-plant transfer coefficients were evaluated. Measurements were made by gamma spectrometry method employing a 90 cc HpGe detector and a 3 x 3-inch well type NaI(Tl) detector. Results show significant levels of 137Cs activity in soil samples--ranging from below detection limit (BDL) to 65.4 Bq kg(-1). The mean value of activity observed in 0-5 cm soil profiles of Kaiga environs is significantly higher when compared to the reported values for other environs of India. Depth profile studies show that the 137Cs activity decreases with the increasing soil depth, and it is below detection limit for depths more than 25 cm. The mean value of effective dose commitment due to the presence of 137Cs in soil was 167.2 microSv. Vegetation samples of the region show elevated levels of 137Cs concentration. Epiphytic plants Cymbidium aloifolium (Lo.) Swartz. and Petrobryopsis tumida (Hook.) Dix. have been identified as bio-indicators to monitor the fallout of this radionuclide in the environment of Kaiga. Seasonal variation studies indicate higher fallout of this radionuclide along with rain.

Systematic studies on gamma radiation level and the distribution of natural radionuclides were carried out under a pre-operational survey for the establishment of baseline data on background radiation level and the distribution of radio-nuclides in the environment of Kaiga, in the south west coast of India, where a nuclear power reactor of 235 MWe has just been commissioned. The external gamma absorbed dose rates prevailing in the region were measured using a portable plastic scintillometer. Soil samples from 18 stations were collected from depth intervals of 0-5, 5-10, and 10-25 cm and analyzed for their 226Ra, 232Th, and 40K activity concentrations by gamma spectrometry employing a 90 cc PGT HpGe detector coupled to an EG&G ORTEC 8K multichannel analyzer. The activity of 226Ra was found to vary between 15.5-61.2 Bq kg(-1) with a mean value of 31.3 Bq kg(-1), that of 232Th varies between 11.4-41.9 Bq kg(-1) with a mean value of 27.5 Bq kg(-1) and of 40K between 78.3-254.8 Bq kg(-1) with a mean value of 159.9 Bq kg(-1) in 0-5 cm soil profiles of the region. The contributions of 238U, 232Th, and 40K to the total gamma absorbed dose rate were 39.9%, 40.7%, and 16.0%, respectively. The gamma absorbed dose rate in air estimated using the results of activity concentration of 226Ra, 232Th, and 40K are found to compare well with that of the direct measurement. The results of the study were compared with the literature values reported for other environs of the country as well as the world, and conclusions are drawn.

Studies on radiation level and radionuclide distribution in the region of Coastal Karnataka, India, were undertaken. The purpose of this study is to provide baseline data on radiation level and radionuclide distribution in the region for the future assessment of the impact of the nuclear and thermal power stations that are being set up in the region. Further, this study may reveal information on the transportation of radionuclides in the environment. The external gamma dose rates in air have been measured throughout Coastal Karnataka using a sensitive plastic scintillometer. The measured dose rates include both terrestrial and cosmic ray components. The gamma dose rates in air range from 26 to 174 nGy h(-1) with a median value of 74 nGy h(-1). The activities of naturally occurring radionuclides in the soil samples of the region were measured using HPGe gamma ray spectrometry, and the resulting doses in air were calculated. The activity of 40K varies from 61.0 to 316.7 Bq kg(-1) with a median of 117.5 Bq kg(-1); the activity of 226Ra varies from 20.1 to 62.3 Bq kg(-1) with a median value 35.0 Bq kg(-1) and that of 232Th from 14.3 to 48.6 Bq kg(-1) with a median value of 29.8 Bq kg(-1). The mean absorbed dose rate in air due to naturally occurring radionuclides is found to be 41.5 nGy h(-1). In addition to this, the correlations between 226Ra and 40K, 232Th and 40K, and 226Ra and 232Th were computed from the results of the concentration of these naturally occurring radionuclides. A weak correlation was observed between 226Ra and 40K and between 232Th and 40K while a moderately good correlation was observed between 226Ra and 232Th. The results of these systematic investigations are presented and discussed in this paper.

In order to understand the distribution of radionuclides in the newly discovered high background area in Ullal near Mangalore, soil and sand samples collected from different depths were analyzed for the concentration of primordial radionuclides by gamma spectrometry. The activity of 232Th and 238U in soil and sand was observed to be maximum in the 0-10 cm layer. The activity of primordial radionuclides was determined for the different size fractions of soil and sand to study the enrichment pattern. The highest activity was found in the 250-125 mu fraction in both soil and sand. The concentration of primordial radionuclides in riverine and marine sediments in the vicinity of the high background area was measured to understand the transportation of radionuclides in riverine and marine environments and to throw light on the formation of the new patches of monazite deposit. The results of these systematic investigations are discussed in this paper.

The systematic study of background radiation and the distribution of radionuclides in the environment of coastal Karnataka, South India, has been initiated with an objective of establishing reliable baseline data on the background radiation level of the region for future assessment of the impact of nuclear and thermal power stations that are being set up in the region. The ambient gamma radiation survey in the environment of Mangalore, a major industrial city of coastal Karnataka, revealed significantly high gamma dose in air in certain locations of the Mangalore beach area. Thermoluminescent dosimetric studies indicated conspicuously high gamma dose in air in these places. Gamma spectrometric analyses of the soil and sand samples of this high background area have been carried out. The measured gamma dose in air in high background area is in the range 44-2102 nGy h-1. The average activity of 232Th, 238U, and 40K in soil samples is 2,971 Bq kg-1, 546 Bq kg-1, and 268 Bq kg-1, respectively. In sand samples, the respective activities are 1,842 Bq kg-1, 374 Bq kg-1, and 158 Bq kg-1. Results of these systematic investigations which establish the existence of new patches of monazite in the Mangalore beach area, on the southwest coast of India, are presented in this paper.