Anthropogenic 137Cs Research Articles

Evaluation of radioactive pollution in sediment samples of Borçka Dam Lake, Turkey

In this research, the concentrations of natural (226Ra, 232Th and 40K) and anthropogenic (137Cs) radionuclides were measured in sediment samples collected from the Borçka Dam Lake using a high purity germanium detector (HPGe). The activity values ranged from 4.79-21.46, 9.36–20.65, 238.01–721.26 and 0.79–6.81 Bq kg-1 for 226Ra, 232Th, 40K and 137Cs respectively. The average 226Ra, 232Th and 40K activity concentrations calculated for the sediment samples were found to be lower compared to world average values reported by UNSCEAR. In addition, radiological hazard indices were determined and compared with the international permissible values. The results of this study revealed that there is no significant health risk for people exposed to sediment samples in this region.

Radioactivity Investigation of the Anthropogenic 137Cs Radionuclide in Soil Samples from the Marapasta Region in Iraqi Kurdistan.

Radioactivity Investigation of the Anthropogenic 137Cs Radionuclide in Soil Samples from the Marapasta Region in Iraqi Kurdistan.

Natural and anthropogenic gamma-ray emitters and iron-bearing compounds distribution in peatlands of the southern Espinhaço mountain chain, Brazil

To help understand the dynamics of peatlands forming on the Southern Serra do Espinhaço, Brazil, the occurring natural (226Ra, 232Th, 40K) and anthropogenic (137Cs) activity of gamma-ray emitters located at three sites, namely the localities of São João da Chapada (CH), Pinheiro (PIN) and Pau de Fruta (PDF), was studied. The iron compounds were characterized by 57Fe Mössbauer spectroscopy. Differences on natural radionuclide levels and distributions were found among the peatland sites, indicating differences on mineral composition, hydric regimes and living. Significant correlation was found only for 232Th–226Ra activity values (Pearson correlation coefficient of − 0.5), which is different from other South American soils, where significant positive correlations among all radionuclides were determined. In PDF and CH, the dose rate results are lower than the worldwide mean value, but in PIN, they are higher because of the relatively high 226Ra concentration. The only anthropogenic radionuclide is 137Cs. The convection–diffusion model fits the CH and PDF activity profiles, although the PIN profile is likely affected by other soil mechanisms as well. Mössbauer spectra reveal Fe3+ in two different local environments and the occurrence of hematite in the upper samples of the CH site. The iron concentration decreases with depth. Contrary to soils of other regions, no significant correlation was found between iron species and the natural radioactivity. The studied peatlands exhibit clear differences between their natural and anthropogenic radionuclide distributions to those of mineral soils.

Measurement of natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) gamma radiation and radiological hazard assessment in beach sand samples collected from Ao Phrao at Koh Samet in Rayong province (Thailand)

In the present research, the main objectives were to measure and analyze the specific activities of natural (40K, 226Ra and 232Th) radionuclides in 30 beach sand samples collected from Ao Phrao after the Rayong oil spill disaster. This huge Petroleum Authority of Thailand (PTT) oil spill occurred on July 27, 2013, in the Gulf of Thailand nearby Ao Phrao at Koh Samet in Rayong province in eastern region of Thailand. At the same time, anthropogenic (137Cs) radionuclides accumulated in the studied area was also studied and presented. High-purity germanium (HPGe) detector with a massive lead shield, some standard reference material sources and gamma spectrometry technique, were used to measure and analyze all of the experimental results. The frequency distribution of specific activities of 40K, 226Ra, 232Th and 137Cs were also evaluated and found to be the asymmetrical distribution. The median values of 40K, 226Ra, 232Th and 137Cs were 173.55 ± 67.04, 10.76 ± 1.71, 6.35 ± 0.75 and 0.24 ± 0.10 Bq/kg, respectively. Furthermore, the associated radiological hazard indices for the studied area were calculated and compared to nationally and internationally recommended values. It was found that the beach sand samples from the study area provide no excessive exposures created from the oil spill for inhabitants. Moreover, the radioactive contour maps of the investigated area were also imaged and presented in this study. The data presented in the study are importance since they create the baseline of the radiological hazard data and mapping of the investigated area in the future.

Food Salt Characterization in Terms of Radioactivity and Metals Contamination

The analysis of food salt is very important because of its high consumption by the population, for both medicinal and nutritional use. In this study, nine different samples of food salt (Cyprus black, Himalayan pink, Hawaii red, iodized, hyposodic iodized, Maldon smoked sea, common sea, Breton sea and Persia blue), coming from large Italian retailers and employed by people for different cooking food purposes, were investigated through High Purity Germanium (HPGe) Gamma Spectrometry in order to evaluate the anthropogenic (137Cs) and natural (40K) radioisotopes activity concentration, and used Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in order to assess any possible metals contamination by a comparison between Cu, As, Cd, Hg and Pb concentrations and the limits set by the Italian Legislation. The evaluation of dose levels due to the salt ingestion for the age category higher than 17 years was performed taking into account the human body daily need of about 10 g of salt, and in the precautionary hypothesis, this need was satisfied from a single type of salt. All obtained results are under allowable levels (1 mSv/year), thus excluding the risk of ionizing radiation effects on humans. Regarding to the metals concentration, experimental results show that it is lower than the contamination threshold values, thus excluding their presence as pollutants.

Determination of 210Po in low-level wild bilberries reference material for quality control assurance in environmental analysis using extraction chromatography and α-particle spectroscopy

Abstract Certified reference materials (CRM) are being widely used for quality control assurance in environmental analysis. For certain CRM, the analytes and/or the range of concentrations are not be available or certified at all. The Joint Research Centre – Institute for Reference Materials and Measurements (JRC-IRMM) of the European Commission has issued a CRM of Wild Berries (IRMM-426) in order to validate radionuclide measurement methods for activity concentrations of the natural radionuclide 40K and the anthropogenic nuclides 90Sr and 137Cs, but not for 210Po. The aim of the work was to determine low-level activity concentration of 210Po in these wild berries. The activity concentration of 210Po was assessed by α-particle spectroscopy after dissolution of the sample by wet digestion and chemical isolation of Po by extraction chromatography. According to the time elapsed since sample collection, the results here shown can be useful not only for ultra low-level analysis of 210Po but also for 210Pb in the reference material.

Natural and anthropogenic radionuclides in Norwegian farmed Atlantic salmon (Salmo salar)

Norway is one of the main producers of farmed fish and the world's second-largest exporter of seafood. Farmed Atlantic salmon (Salmo salar) represents the most exported species. This is the first comprehensive survey of anthropogenic (137Cs, 90Sr, 238Pu, 239,240Pu and 241Am) and natural (40K, 226Ra, 228Ra, 210Pb, 210Po) radionuclides in farmed salmon and manufactured fish feed from Norway. The only anthropogenic radionuclide detected in salmon and fish feed was 137Cs. The levels were low with arithmetic means in salmon and feed of 0.13 and 0.30 Bq/kg fresh weight (fw), respectively. The natural radionuclide 40K exhibited the highest levels with arithmetic means in salmon and feed of 115 and 239 Bq/kg fw, respectively. The arithmetic means of 210Po and 210Pb in salmon were 0.013 and 0.044 Bq/kg fw, respectively, with a mean 210Po:210Pb activity ratio of 0.32. For fish feed, the situation was reversed: the arithmetic means of 210Po and 210Pb were 3.8 and 0.67 Bq/kg fw, respectively, with a mean 210Po:210Pb activity ratio of 5.7. The radionuclide levels found in farmed salmon in the present study are comparable to or lower than the levels found in other fish species in the North Atlantic Ocean. A highly conservative dose estimate for consumption showed that doses were no higher than 1.2 μSv/year for toddlers and 4.0 μSv/year for adults. This suggests that the risk associated with radioactivity in farmed salmon is very low even when considering individuals with high consumption and the highest radionuclide levels found in this study.

Developmental and hemocytological effects of ingesting Fukushima\u2019s radiocesium on the cabbage white butterfly Pieris rapae

High morphological abnormality and mortality rates have been reported in the pale grass blue butterfly, Zizeeria maha, since the Fukushima nuclear accident. However, it remains uncertain if these effects are restricted to this butterfly. Here, we evaluated the effects of ingesting cabbage leaves grown with contaminated soils from Fukushima on the development and hemocytes of the cabbage white butterfly, Pieris rapae. Contaminated cabbage leaves containing various low levels of anthropogenic 134Cs and 137Cs radioactivity (less than natural 40K radioactivity) were fed to larvae from Okinawa, the least contaminated locality in Japan. Negative developmental and morphological effects were detected in the experimental groups. The cesium (but not potassium) radioactivity concentration was negatively correlated with the granulocyte percentage in hemolymph, and the granulocyte percentage was positively correlated with the pupal eclosion rate, the adult achievement rate, and the total normality rate. These results demonstrated that ingesting low-level radiocesium contaminants in Fukushima (but not natural radiopotassium) imposed biologically negative effects on the cabbage white butterfly, as in the pale grass blue butterfly, at both cellular and organismal levels.

Estimation of background radiation levels and associated health risks in mineral rich district Chiniot, Pakistan

The mineral extraction activities may disturb the natural radioactivity, therefore current study aims to generate baseline data of natural radionuclides and anthropogenic 137Cs before the start of industrial activities. Gamma spectrometry and gross alpha and beta counting systems were used for activity measurement in environmental samples. In soil, the mean activity of 232Th, 226Ra, 40K and 137Cs were determined as 79 (66–117), 47 (34–80), 823 (602–1159) and 1.3 (1.1–4.5) Bq kg−1, respectively. The average annual effective dose rate (128.7 µSv h−1) in the study area was twice higher than world’s average value. Indoor hazard index was greater than unity at two places; therefore, proper ventilation is proposed during construction.

Multi-element composition of soil, mosses and mushrooms and assessment of natural and artificial radioactivity of a pristine temperate rainforest system (Slavonia, Croatia)

This study investigates multi-element composition of soil, mosses and mushrooms from a pristine temperate rainforest (Prašnik, Croatia). Additionally, the activity levels of natural (238U, 235U and 232Th decay chains, 40K and 7Be) and anthropogenic (137Cs and 134Cs) radionuclides in the investigated soil samples, obtained by gamma spectrometry, provide baseline of environmental radioactivity levels in this area. The aim of investigation was to explore the uptake of metal(loid)s by bioindicator species (mosses, mushrooms) growing in a pristine environment characterized by naturally elevated concentration of metals. The calculated enrichment and bioaccumulation factors, correlations between different groups of elements and similar multi-element patterns in mosses, mushrooms and soil samples revealed the prevailing influence of the local substrate geochemistry on element concentrations in mosses and mushrooms. The results suggest atmospheric deposition of Bi, Cd and Pb, while radionuclide activities point to atmospheric fall-out (including global contamination by radiocaesium) and influence of the pedological substrate. The confined area of investigation, with limited variations in soil characteristics and geological composition, allowed clearer insight into the origin of metal(loid)s in mosses and mushrooms. On the other hand, using bioindicator species with different element uptake mechanisms enabled distinction between different sources of elements.

Radionuclide distribution in soil and undecayed vegetative litter samples in a riparian system at the Savannah River Site, SC

The aim of this study is to comprehensively investigate radionuclide concentrations in surface soil and un-decayed vegetative litter along four stream systems (i.e. Fourmile Branch, Lower Three Runs, Pen Branch, and Steel Creek) at the Savannah River Site (SRS), Aiken, South Carolina. Soil and litter samples from systematically spaced 12 pairs (contaminated or uncontaminated) of plots along the four streams were analyzed for 16 distinct radionuclide activities. Lower radionuclide concentrations were observed in soil and litter samples collected along Pen Branch compared to the other 3 streams. The anthropogenic radionuclide with the highest activity was 137Cs in soil (10.6–916.9 Bq/kg) and litter (8.0–222.3 Bq/kg), while the naturally occurring radionuclides possessing the highest concentration in the samples were 40K (33.5–153.7 Bq/kg and 23.1–56.0 Bq/kg in soil and litter respectively) and 226Ra (55.6–159.9 Bq/kg and 30.2–101.8 Bq/kg in soil and litter respectively). A significant difference (p < 0.05) of radionuclide concentrations between paired-plots across four streams was observed for 241Am, 137Cs, 238Pu, 239Pu, and 226Ra in both contaminated and non-contaminated samples. 137Cs and uranium isotopes had the highest litter-to-soil correlation in contaminated (rho = 0.70) and uncontaminated plots (rho = 0.31–0.41), respectively. 90Sr was the only radionuclide with higher radioactive concentrations in litter (12.65–37.56 Bq/kg) compared to soil (1.61–4.79 Bq/kg). The result indicates that 1) historical discharges of anthropogenic 137Cs was the most important contributor of radiation contamination in the riparian environment at SRS, 2) 90Sr was the only radionuclide with higher concentration in litter than in soil, and 3) no apparent pattern in deposition density in soil or litter along downstream was observed for the radionuclides measured in this study.

Assessment of Some Trace Chemical Elements in Cajío Beach Peloid Using Nuclear Analytical Techniques

A peloid is a maturated mud or muddy dispersion with healing and/or cosmetic properties, composed of a complex mixture of fine-grained natural materials of geologic and/or biologic origin, mineral water or seawater, and common organic compounds from biological metabolic activity. Cajio beach peloid is a traditional peloid of the south coast of Güira de Melena municipality located in Artemisa province, Cuba. The peloid is a sea mud, used in situ, by the population of the locality. The present study has tree aims: ones is to determine trace chemical elements content (Sc, Cs, La, Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb, Hf, Ta, Th and U). The second aim is to determine natural (226Ra, 238U, 232Th, 210Pb, 40K) and the anthropogenic (137Cs) radionuclides in the peloid. Finally, to assess the level of contamination and radiological risk for the users of the peloid therapeutic practices.

Anthropogenic 137Cs on atmospheric aerosols in Bratislava and around nuclear power plants in Slovakia

Nuclear power plants (NPPs) have been one of the sources of anthropogenic radionuclides in the environment. This work combines the results from monitoring stations around NPPs in Slovakia (Mochovce and Jaslovské Bohunice) and academic measurements at the Comenius University campus in Bratislava. Most of the atmospheric 137Cs in this region come from the resuspension of the Chernobyl-derived 137Cs, as well as caesium produced during nuclear weapons testing. By comparison of the obtained results at NPPs with Bratislava data, radiation impacts of the NPPs on the local environments have been estimated to be negligible.

Fukushima-derived radioactivity measurements in Pacific salmon and soil samples collected in British Columbia, Canada

Despite the many studies that have shown minimal health risks to individuals living outside of Japan following the Fukushima Nuclear Accident, there are persisting concerns regarding the consumption of Pacific seafood that may be contaminated with radioactive species from Fukushima. To address these concerns, the activity concentrations of anthropogenic 134Cs and 137Cs, as well as naturally occurring 40K, were measured in Pacific salmon collected from Kilby Provincial Park, British Columbia (BC), in 2013 and from the Quesnel River, BC, in 2014 using low-background gamma-ray spectroscopy. In addition, soil samples and a single roof-debris sample were collected and analysed to provide a record of Fukushima-derived contamination in BC. Cesium-134 was not detected in the salmon samples. Cesium-137 was not detected in any of the sockeye or chum samples, although it was detected in all of the Chinook samples. The weighted average (±1σ) 137Cs activity concentration in the Chinook salmon collected in 2013 and 2014 was 0.23 (3) and 0.20 (3) Bq/kg fresh weight, respectively. A conservative annual dose estimate for an adult who consumes the average Canadian quantity of seafood per year, contaminated with radiocesium at the maximum concentrations measured in this campaign, was calculated to be 0.054 μSv per year. Cesium-134 was detected in all but two of the soil samples. A weak positive correlation was observed between presence of 134Cs and of 7Be suggesting that the 134Cs arrived via atmospheric deposition. Cesium-137 was present in every soil sample, although the total radiocesium activity concentrations measured were significantly less than action levels set by Health Canada.

Environmental Radiation Measurement and Assessment of Natural Radioactivity in Soil, Water and Vegetation

Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40K), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity because of the constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine and estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Yangdong District, Yangxi County, and Yangjiang County of Guangdong Province, China using an HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40K in soil samples was found to be 31.19 ± 1.2, 47.00 ± 2.30 and 589.31 ± 17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40K in vegetation samples was 19.92 ± 3.09, 25.36 ± 8.11 and 4982.94 ± 85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSvy-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment.

Identification of the earlier human-induced sedimentation change in Daya Bay, northern South China Sea using 210Pb and 137Cs

Over the past 30years, the rapid development of the Chinese economy resulted in environmental problems, especially in coastal areas. To discern the effects of anthropogenic activities, 210Pb and 137Cs were examined in the sediment from Daya Bay, northern South China Sea. The specific activity of 137Cs showed a clear maximum, corresponding to 1963. 210Pb specific activity varied from 25.1 to 78.5Bq kg−1. 210Pb distribution showed a hiatus at 18–19cm with 5–6cm of older sediment (>150years), indicating direct land-originating material over a short timescale rather than natural processes. This event was attributed to the human-induced redistribution of sediment during reclamation. Based on the 137Cs-labeled 1963 and 210Pb-chronologies, this event was confined to late 1977, earlier than the generally recognized significant anthropogenic activities. Thus, information archived in the sediment or in records prior to the 1970s would be better environmental background in Daya Bay.

Natural and artificial radionuclides in a marine core. First results of 236U in North Atlantic Ocean sediments

There are very few data available of 236U in marine sediment cores. In this study we present the results from the first oceanic depth profile of 236U in a sediment core sampled in the North Atlantic Ocean, at the PAP site (4500 m depth, Porcupine Abyssal Plain (PAP) site, 49°0′ N, 16°30′ W). Additionally, the sediment core was radiologically characterized through the measurement of anthropogenic 137Cs, 239Pu, 240Pu, 129I and 14C and natural 210Pb, 40K and 226Ra.The measured 236U concentrations decrease from about 90·106 at g−1 at the seafloor down to 0.5·106 at g−1 at 6 cm depth. They are several orders of magnitude lower than the reported values for soils from the Northern Hemisphere solely influenced by global fallout (i.e. from 2700·106 to 7500·106 at g−1). 236U/238U atom ratios measured are at least three orders of magnitude above the estimated level for the naturally occurring dissolved uranium. The obtained inventories are 1·1012 at m−2 for 236U, 80 Bq m−2 for 137Cs, 45 Bq m−2 for 239+240Pu and 2.6·1012 at m−2 for 129I. Atomic ratios for 236U/239Pu, 137Cs/236U and 129I/236U, obtained from the inventories are 0.036, 0.11 and 2.5 respectively. Concentration profiles show mobilization probably due to bioturbation from the abundant detritivore holothurian species living at the PAP site sea-floor. The range of 236U, 137Cs, 239+240Pu and 129I values, inventories and ratios of these anthropogenic radionuclides are more similar to the values due to fall-out than values from a contribution from the Nuclear Fuel Reprocessing Plants dispersed to the south-west of the North Atlantic Ocean. However, signs of an additional source are detected and might be associated to the nuclear wastes dumped on the Eastern North Atlantic Ocean.

Sources of 137Cs to an Arctic fjord (Hornsund, Svalbard)

Although primary sources of anthropogenic 137Cs have decreased nowadays, the Arctic is exposed to a variety of secondary sources. These include riverine run-off, oceanic currents, drifting sea ice, melting glaciers and permafrost. Recent reports underline the role of glaciers, specifically cryoconite holes, in radionuclide accumulation. Therefore, this study investigates the hypothesis that melting glaciers are an important means of delivering 137Cs for Arctic fjord (Hornsund, Svalbard). As marine sediments are the final sink for most contaminants, seven 30–40 cm long sediment cores collected in 2016 were investigated for 137Cs activity concentration. Five were collected in a transect from the central to the outer part of the fjord while two were collected within one km of the different melting tidewater glaciers. Sediment layers were dated using 210Pb to reveal the history of 137Cs accumulation. The measured 137Cs activity concentrations ranged from <0.1 to 7.7 Bq kg−1. The activity concentrations ranging from 0.3 to 3.1 Bq kg−1 were measured in surface (0–2 cm) sediments. The total 137Cs inventories were calculated for five station and ranged from 322 to 908 Bq m−2, of which 29–34 Bq m−2 were deposited within the last decade. At two stations characterized by largest sediment accumulation rates only the last decade inventories were calculated and they ranged from 13 to 444 Bq·m−2. The mean of 137Cs fluxes calculated for last decade ranged from 2.7 to 44.1 Bq m−2yr−1. The history of 137Cs environmental inputs was well revealed in the sediments as the 137Cs penetration depth agreed with the time of its introduction to the Arctic and the most pronounced 137Cs activity concentration peak was found in sediments dated for circa 1963. Although 137Cs fluxes and inventories were largest in the glacial bay (Brepollen), the 137Cs was diluted in a large amount of sedimenting material. Based on the results in this study, the glaciers do not appear to act as important sources of 137Cs to the marine environment in the Hornsund fjord.

Specific activities and radiological hazard assessment in beach sand samples in Songkhla province, Thailand after Fukushima Dai-Ichi nuclear power plant accident in Japan

According to the Fukushima Dai-Ichi Nuclear Power Plant Accident in Japan on March 11, 2011, specific activities of natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides in 210 beach sand samples which were collected from Maharat, Sai Kaew, Samila, Chalatat, Na Thab, Sakom and Soi Sawan beaches in Songkhla Province along the eastern coast of Thailand, have been studied and evaluated. The specific activity levels of 40K, 226Ra, 232Th and 137Cs in the area were found in the range 110.13 – 4574.12, 6.99 – 451.87, 3.75 – 665.76 and 0.58– 9.91 Bq/Kg, respectively. Furthermore, the median values of specific activities of 40K, 226Ra, 232Th and 137Cs were calculated and compared with other research data in Thailand as well as global measurements and evaluations. Moreover, four radiological hazard indices for the studied area were also assessed by using the median values of specific activities of 40K, 226Ra and 232Th.

Measurement of Gamma Emitting Radionuclides in Environmental Samples of Talagang Tehsil-District Chakwal

Due to constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine/estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Talagang Tehsil-District Chakwal of Pakistan using a HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40K in soil samples was found to be 31.19±1.2, 47.00±2.30 and 589.31±17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40K in vegetation samples was 19.92±3.09, 25.36±8.11 and 4982.94±85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSv y-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment.