210Po Activity Concentrations Research Articles

Assessment of cancer risk and radiological effects from 210Po and 210Pb with consumption of wild medicinal herbal plants

BackgroundPlants' raw materials can accumulate chemical elements, including radioisotopes, to some extent and reflect the region they grow in. Due to their high environmental content and toxicity, natural radionuclides – polonium 210Po and lead 210Pb are the most dangerous radioisotopes for human health. Methods70 raw medicinal herbal materials from 54 popular wild-growing medicinal plant species, most of them included in the European Pharmacopoeia, were collected across three regions. In 210 samples, the activity concentrations of 210Po and 210Pb were determined, and their radiotoxicity and cancer risk were calculated. ResultsThe results of 210Po and 210Pb activities measured in herbal raw material were from 0.12 mBq g−1 dry weight in the fruits of the common chestnut (Aesculus hippocastanum) to 19.7 mBq g−1 dw in herb of ground elder (Aegopodium podagraria) for 210Po, while for 210Pb ranged from 0.16 mBq g−1 dw to 34.3 mBq g−1 dw in the same plants. There were statistically significant differences between 210Po and 210Pb content in leaves, herbs, flowers, and fruit. The studies indicated that the estimated annual effective radiation dose from Polish medicinal herbs consumption was low, ranging 0.03–105 µSv from 210Po and 0.02–98.2 µSv from 210Pb, while the risk of cancer morbidity and mortality ranged from 10−5 to 10−9. ConclusionsConsumption of the tested medicinal herbs is safe from the radiological point of view and, based on the predictions related to the calculated risk of cancer, should not increase the probability of its occurrence.

Assessment of Be-7, Pb-210 and Po-210 Activities in Airborne Particulate Matter Over Istanbul, Türkiye.

Airborne particulate matter is one of the air pollutants which can have detrimental health effects in the human body. Radionuclides adsorb onto air particles and make their way to humans primarily through inhalation. Naturally-occurring radionuclides, 210Pb and 210Po, are of notable health concern due to their relatively elevated ingestion and inhalation doses. In the current study, activity concentrations of 7Be, 210Pb and 210Po were determined in air particulate matter (PM). PM2.5 was collected on the European side, while PM10 was collected on the Anatolian side of Istanbul. Be-7, 210Pb and 210Po activities were found to be 5.17 ± 2.35, 0.96 ± 0.42; 0.25 ± 0.14 mBq m- 3 in Anatolian side, respectively. Be-7, 210Pb and 210Po activities were found to be 3.81 ± 2.27, 0.62 ± 0.29, 0.29 ± 0.26, mBq m- 3 in European side, respectively. The ratio of 210Po/210Pb was found to be higher (0.47 ± 0.31 for PM2.5 and 0.34 ± 0.27 for PM10) than the global average of 0.1. This result can be explained by the fact that Po is more volatile than Pb and enhanced in the air by the combustion process. Inhalation dose rates of 210Pb and 210Po due to PM10 exposure were calculated to be 7.70 ± 3.30 and 4.05 ± 2.31 µSv year- 1, respectively. Pb-210 bioaccessibility was assessed by the extraction of the particles in simulated lung fluids. Approximately 24.8% of inhaled 210Pb was estimated to be bioaccessible. This study suggests that 210Po and 210Pb activities are partially enhanced in the air particles in Istanbul and should be regularly monitored.

Characterizing 226Ra and its daughters in coastal zone groundwater of a typical human-activity affected bay: occurrence, safety, and source evaluation.

Due to their extremely toxic properties, 226Ra and it daughters (222Rn, 210Pb, and 210Po) in drinking groundwater require monitoring. Recent studies have reported exceptionally high levels of natural 210Po (up to 10,000Bq/m3), 226Ra, and 222Rn isotopes in groundwater. This study aims to provide background data on 226Ra and its daughter radionuclides in the typical agricultural-industrial Dongshan Bay (DSB) before the construction of Zhangzhou Nuclear Power Plant (Zhangzhou NPP). The measurement results indicate that no abnormally high activities of 210Po and 210Pb were detected in the investigated wells. Strong positive correlations between 210Pb and 210Po, as well as between 222Rn and 210Pb activities, suggest that the origins of 210Pb and 210Po in groundwater are strongly influenced by the decay of the parent radionuclides 222Rn and 210Pb, respectively. In the DSB coastal zone groundwater, significant deficiencies of 210Po relative to 210Pb and 210Pb relative to 222Rn were observed, providing further evidence that 210Po and 210Pb are also effectively scavenged due to their geochemical properties (specifically particle affinity) within the groundwater-aquifer system. A systematic comparison among all relevant water bodies in the DSB revealed that the activity concentrations of 210Pb and 210Po in groundwater were the highest, except for rainwater. Based on the evaluation of 210Pb sources, the results imply that submarine groundwater discharge (SGD) is an important pathway for transferring radionuclides (such as 210Pb) from land to the nearshore marine environment, even though the study area has a lower 210Pb background groundwater. By considering all the 210Pb's sources in the DSB, we found low 210Pb background groundwater discharge still needs to be taken into account for small-scale bays. This is because SGD was calculated to be one of the most important 210Pb sources in the bay during observation season. Regardless of whether the system is in a normal state or a nuclear accident emergency state, greater attention should be paid to the groundwater discharge of radionuclides into the ocean.

Geochemical behavior of heavy metals and radionuclides in a pit lake affected by acid mine drainage (AMD) in the Muskau Arch (Poland)

Pit lakes in the ‘anthropogenic lake district’ in the Muskau Arch (western Poland; central Europe) are strongly affected by acid mine drainage (AMD). The studied acidic pit lake, ŁK-61 (pH <3), is also exposed to floods due to its location in the flood hazard area, which may significantly influence the geochemical behavior of elements. The elemental compositions of water and lake sediment samples were measured with ICP–OES and ICP–MS. The sediment profile was also examined for 137Cs and 210Po activity concentrations using gamma and alpha spectrometry, respectively. Grain size distribution, mineralogical composition, diatoms, and organic matter content in the collected core were also determined. The key factors responsible for the distribution of selected heavy metals (e.g., Cu, Ni, Pb, Zn) and radioisotopes (137Cs and 210Po) in the bottom sediments of Lake ŁK-61 are their coprecipitation/precipitation with Fe and Al secondary minerals and their sorption onto authigenic and allogenic phases. These processes are likely driven by the lake tributary, which is an important source of dissolved elements. The data also showed that the physiochemical parameters of Lake ŁK-61 water changed during an episodic depositional event, i.e., the flood of the Nysa Łużycka River in the summer of 2010. The flood caused an increase in the water pH, as interpreted from the subfossil diatom studies. The down-core profiles of the studied heavy metal and radionuclide (HMRs) contents were probably affected by this depositional event, which prevented a detailed age determination of the collected lake sediments with 137Cs and 210Pb dating methods. Geochemical modeling indicates that the flood-related shift in the physicochemical parameters of the lake water could have caused the scavenging of dissolved elements by the precipitation of fresh secondary minerals. Moreover, particles contaminated with HMRs have also possibly been delivered by the river, along with the nutrients (e.g., phosphorus and nitrogen).

Radiotoxic 210Po concentration in the Mediterranean Sea sediment and radiation risk assessment of biota

This research presents the levels and distribution of 210Po in different sediments of the northeastern coast of the Mediterranean Sea. The 210Po activity concentrations were measured using an alpha spectroscopy system. The activity concentrations of 210Po in the sediment samples were in the range between 20.5 ± 0.7 and 92.8 ± 1.6 Bq kg−1 dw with an average of 48.2 ± 1.4 Bq kg−1 dw. The microorganism-enriched sampling sites (bedrock sites) indicated low 210Po concentration than sandy coastal sites. As a result of these measurements, the RESidual RADioactivity (RESRAD) biota code was applied to calculate the tissue concentration rate (CR), internal dose rate, external dose rate, and total dose rate of the exposed tissues. The total dose rates of aquatic animals were found higher than that of riparian animals. The 210Po sediment resource doses to aquatic and riparian animals were found less than the dose level recommended by International Commission on Radiological Protection (ICRP).

Po-210 activity concentrations in wild and farmed fish from the Aegean Sea and Sea of Marmara and dose assessment to consumers.

Polonium (210Po) is the major contributor (with approximately 90%) to the radiation dose from radionuclides contained in the human diet, and it is mostly associated with seafood. This study presents 210Po activity concentrations in the tissues of 16 fish species from the Aegean Sea and Sea of Marmara. Among all species investigated, the highest 210Po activity concentration was 4450 ± 33 Bq kg-1 dry weight (dw) in the digestive tract of anchovy (Engraulis encrasicolus), and the lowest 210Po activity concentration was 1.3 ± 0.6 Bq kg-1 (dw) in the muscle tissue of the thornback ray (Raja clavata). Significant differences in 210Po concentrations were consistently found among the tissues of fish (P < 0.05). In general, the prominent accumulation of 210Po was observed in the digestive tract and liver while the muscle tissue generally displayed the lower concentrations. Polonium concentrations in the internal organs, such as muscle and liver, were related to the feeding ecology of fish and thus are a consequence of 210Po transfer in the food chain rather than 210Po uptake from water. The average 210Po concentration in fish filet was 54.1 Bq kg-1 dw and to attain the recommended limit for the annual committed effective dose (1 mSv year-1) would require the consumption of 1024 kg of mixed fish filet in 1 year, which is unlikely to happen. The highest 210Po activity concentration in the edible part of fish (filet) was determined in the anchovy (E. encrasicolus) but to reach the 1mSv year-1 limit would require still the consumption of 7.1 kg year-1 of anchovy filet. Similar size specimens of wild and farmed fish, Dicentrarchus labrax and Sparus aurata, were analyzed to assess the differences in 210Po concentrations. Polonium concentrations in the wild fish were several-fold higher than in farmed specimens, these ones fed with fish feed with 210Po content lower than natural food in the sea. Therefore, the current trend of increasing the consumption of seafood from aquaculture seems to be reducing the radiation exposure to 210Po in the human diet that is considered beneficial to public health.

Seafood dose parameters: Updating 210Po retention factors for cooking, decay loss and mariculture

210Po has been identified as one of the main contributors to ingestion doses to humans, particularly from the consumption of seafood. The amount of 210Po activity concentration data for various types of seafood has increased greatly in recent times. However, to provide realistic seafood dose assessments, most 210Po data requires correction to account for losses that can occur before the seafood is actually consumed. Here we develop generic correction factors for the main processes associated with reduction of 210Po in seafood – leaching during cooking, radioactive decay between harvest and consumption, and sourcing from mariculture versus wild-caught.When seafood is cooked, the overall mean fraction of 210Po retained is 0.74 for all cooking and seafood types, with the means for various seafood types and cooking categories ranging from 0.56 to 1.03. When considering radioactive decay during the period between harvest and consumption, the overall mean fraction remaining is 0.81 across all seafood preservation/packaging types, with estimates ranging from 0.50 (canned seafood) to 0.98 (fresh seafood). Regarding mariculture influence, the available limited data suggest marine fish and crustaceans raised with processed feed have about one order of magnitude lower (×0.10) 210Po muscle content than wild-caught seafood of the same or similar species, although this ratio varies.Overall, this study concludes that 210Po activity concentrations in seafood at the time of ingestion may be reduced to only about 55% compared to when it was harvested. Therefore, correction factors must be applied to any data derived from environmental monitoring in order to achieve realistic dose estimates. The data also suggest lower 210Po ingestion doses for consumers who routinely favour cooked, long shelf-life and farmed fish/crustaceans. However, more data is needed in some categories, especially for cooking of molluscs and seaweed, and for the 210Po content in all farmed seafood.

Biodistribution of 210Po in seafood and risk assessment for consumers in Sweden

Seafood consumption per capita, in Sweden, is larger than World and European average. Although, 36% of Swedes consume seafood meals at least two times per week, the Swedish National Food Agency advises the necessity to increase this ratio. Seafood is one of the main entrances of 210Po in the human food chain. Due to the high radiotoxicity, the intake of 210Po plays an important role in the human health, even in extremely small quantities. In this study, 114 seafood samples representing 52 different marine species were analyzed. The biodistribution of 210Po in seafood species were not uniformly distributed being higher in digestive system and gonads, and lower in seafood muscle. The activity concentration of 210Po in fish ranged between 0.01 and 26 Bq/kg with an average value of 4 Bq/kg, whereas in shellfish fluctuated between 0.1 and 239 Bq/kg, with a mean concentration of 18 Bq/kg. In general, the activity concentration of 210Po in processed products were lower than fresh samples due to the decay of 210Po from seafood capture to purchase. However, in boiled seafood such as Norway Lobster, with short elapsed time from collection to purchase, the boil samples presented higher activity concentration of 210Po than fresh products. The results of the study showed that the annual intake of 210Po via seafood consumption in Sweden exponentially increased by age and it was slightly higher in males than females. As a result, the annual committed dose ranged from 60 to 154 μSv, with an average value of 103 ± 31 μSv, being controlled by fish consumption below 14 years old and by seafood consumption above 14 years old. Finally, the committed effective dose could increase up to 479 μSv/y for population group with higher seafood consumption.

On 210Po and 210Pb in algae diet supplements — The assessed radiation hazard of aquatic superfoods

Algae are believed to give health benefits. However, the studies showed they contain toxic elements, including radionuclides, and may affect human health. The study presents the values of activity concentrations of 210Po and 210Pb in the algae supplements available worldwide for adults. The activity concentrations (Bq/kg dw) ranged from 0.07 to 14.5 (210Po) and from 0.06 to 8.48 (210Pb). Also, the effective radiation doses and the cancer risk from 210Po and 210Pb decay ingested with analyzed algal supplements have been assessed. The highest values of annual effective doses have been estimated for 210Po in the recommended portion of Spirulina (Arthrospira platensis) from China (59.7 μSv/year) and Diatomaceous earth from the USA (50.4 μSv/year). The cancer morbidity and mortality risk ranged from 10−4 to 10−8. The study indicated the activity concentrations of 210Po and 210Pb were low, and algae supplements for human consumption could be considered safe food.

Conversion factor and other variables in the indoor retrospective radon activity concentration studies

Estimation of indoor retrospective radon activity concentration can be performed by measuring the 210Po surface activity concentration of the radon progeny on mirrors. The conversion factor between the surface activity concentration of 210Po on mirrors and the retrospective activity concentration of 222Rn in the air was determined. Several places and some variables have been considered. Exposures were performed in places with moderate and high concentrations of 222Rn. The repeatability of results has been investigated. The dependence of concentration on exposure time has been checked. The effect of cleaning the mirror surfaces has been analyzed. The experimental results obtained for the possible 210Pb-210Po equilibrium inside the mirrors have also been studied and compared with the theoretically expected values.

Revisiting methods for the assessment of naturally-occurring radioactivity in drinking water

A comprehensive radioactivity characterisation of Castilla y León (Spain) groundwater intakes intended for human consumption is addressed between 2017 and 2021. This study responds to the radiological requirements stated in the European Council Directive 51/2013/EURATOM concerning drinking water for public health. Given that the gross α- and gross β-activity determination is used as a screening strategy for water radioactivity monitoring, the reliability of the thin-source deposit method (ISO 10704, 2019) has been improved to achieve representative values of the total activity coming from α- and β-particle emitters in the samples. More than 400 groundwater samples have been considered for this purpose, analysing their 238,235,234U, 228,226Ra, 210Pb, and 210Po activity concentrations, which are needed for the indicative dose assessment. These results, considered reference activity values, are compared with the gross α- and gross β-activities determined by the different procedure approaches. Ultimately, the results of the liquid scintillation counting method (ISO 11704, 2018) are also used to validate the optimised method.

Study of Polonium (210Po) Activity Concentration in Fruit Wines Derived from Different Locations in Poland.

This study aimed at assessing the activity concentration and the annual effective dose of polonium-210 (210Po) in fruit wines derived from four locations in Poland (Warmian-Masurian, Podlaskie, Lubelskie and Małopolskie voivodeships). The fruit wines differed significantly (p &lt; 0.05) in 210Po activity depending on the production site, with the Małopolskie site having the highest activity (61.4-221.4 mBq/L) and the Podlaskie having the lowest (3.5-97.1 mBq/L). The site differentiation was due to environmental conditions-soil parameters (uranium concentration), precipitations and terrain characteristics, e.g., the proximity of the lakes. The increased activity concentration of 210Po in samples from Małopolska compared with the other sites probably derived from the environment polluted with aqueous wastes and particulate air pollution. The annual effective dose due to the ingestion of fruit wines ranged from 0.112 to 1.214 µSv/year. These levels of exposure are safe according to the WHO criterion (0.1 mSv per year for ingestion) and to the IAEA reference level for public exposure including food (1 mSv per year). Summing up, the data obtained provide information on the activity concentration of 210Po in fruit wines and increase databases on the natural radioactivity of foodstuffs. Future work is needed to examine 210Po activity in samples from all vineyard regions in Poland.

Bioaccumulation and retention of Po-210 and Pb-210 in two species of mosses from the zone of influence of the former radium-extracting plants.

The presented study was aimed at assessing the ability to accumulate and retain 210Po and 210Pb in two species of the mosses Sphagnum girgensohnii Russow and Pleurozium schreberi (Willd. ex Brid.) Mitt. Mosses were collected in the zone of influence of the former radium-extracting plants (Komi Republic, Russia). 210Po and 210Pb activity concentrations in S. girgensohnii varied from 131 ± 15.4 to 221 ± 18.3Bqkg-1, and from 164 ± 18.6 to 309 ± 26.1Bqkg-1 respectively. In P. schreberi corresponding activity concentrations ranged from 107 ± 18.8 to 328 ± 29.2Bqkg-1 and from 117 ± 13.2 to 399 ± 31.1Bqkg-1. Activity concentrations of 210Po and 210Pb in autumn were higher than in summer. In the young parts of the mosses, they were lower than in the old parts. To assess the ability to retain accumulated radionuclides, watersoluble (distilled H2O), exchangeable (1M CH3COONH4), and acidsoluble (0.1M H2SO4) fractions of 210Po and 210Pb were isolated from the studied mosses by the method sequential extraction. It was revealed that these fractions in total contained up to 26% of 210Po and 39% of 210Pb. The results showed that the studied moss species are a good biogeochemical barrier and long-term storage for 210Pb and 210Po.

Radiological dose and associated risk due to 210Po in commercial inter-tidal bivalves of southwest (Arabian Sea) coast of India

The activity concentration of 210Po was determined in edible tissues of commercial bivalves on the southwest coast of India. The 210Po activity ranged from 38.3 ± 6.9 Bq kg−1 to 91.2 ± 18.6 Bq kg−1. The annual committed effective dose (ACED) and lifetime carcinogenic risk (LCR) were calculated for different age groups to determine the potential health risk associated with bivalve consumption. The average ACED ranged from 81.5 to 194.1 μSv y−1, with the 10th and 95th percentiles being 68 and 261 μSv y−1, respectively. Lifelong mortality risk (LMTR) values ranged from 1.2 × 10−3 to 2.9 × 10−3, while lifetime morbidity risk (LMBR) values ranged from 1.9 × 10−6 to 4.9 × 10−6. The effective dose was found to be within the UNSCEAR limits.

Determining baseline radiation levels in marine biota – A comparison of SE Queensland commercial species

Limited data exists on the contribution to radiological dose to members of the public from ingestion of radioactivity in seafood in the Australian diet. There is also a lack of data available to assess the radiological dose to marine fauna in Australian waters. Natural and anthropogenic radionuclides and trace metals were measured in the edible flesh of prawns to determine the radiological dose to humans. The remaining tissues were combined and analysed to enable uptake and environmental radiological doses to be assessed. Although in international studies, the edible flesh is generally measured to determine radiation dose or ingestion of trace metals, the effects of preparation and cooking techniques are rarely assessed. In this study, cooking and preparation techniques that may influence the radiological dose to humans were assessed. Eggs were also removed from a selected number of samples to assess the potential dose in sensitive developmental tissues and possible implications for environmental effects. Order of magnitude differences in 210Po activity concentrations and Cd concentrations were observed between whole animals and the edible flesh of Australian caught King (Melicertus spp.) and Tiger (Penaeus spp.) prawns, with the hepatopancreas primarily responsible for this difference. Most 210Po was unsupported by 210Pb and activity concentrations of all other radionuclides measured (137Cs, 210Pb, 226Ra, 232Th, and 238U) were very low. The major contribution to radiation dose via the ingestion pathway and to the organism itself was from 210Po. Cooking techniques that may lead to leaching of 210Po from the hepatopancreas could substantially increase the radiological dose from ingestion of this isotope. Organism dose estimates using different input assumptions in the radiological assessment tool “ERICA”, including site-specific tissue activity concentrations with site- or region-specific media concentrations, were compared with ERICA default distribution coefficients (Kd) and concentration ratios.

Polonium content in some economically important fish in Semarang and Cirebon, Indonesia

As a marine country, Indonesia recognizes various sources of healthy food from the ocean, such as fish, shellfish, and seaweed, leading to the Indonesian government actively promoting a fish-eating campaign to improve health. Although fish consumption in Indonesia is increasing, research on the concentration of 210Po in fish has not often been studied. Based on this condition, this study was needed to determine the activity concentration of 210Po in several fish that have high economic value in Semarang and Cirebon, and their relationship with several parameters of oceanography. The 210Po activity measurement method in fish is based on the IAEA-MEL (2005) method. The detected 210Po activity concentrations were 207.3, 71.7, 130.9, 4.46, 112.6, and 251.6 Bq/kg (dw) for skipjack, four-finger, mullet, snapper, pomfret, and ponyfish, respectively. These values are still considered safe compared to the values allowed by the Indonesia Quality Standard Limit (Bappeten), which is 10×103 Bq/kg (dw). Compared to some fish and shellfish used in overseas research, the content of 210Po in some fish in Indonesia is still lower. The activity value of 210Po above 20 Bq/kg was detected in skipjack and ponyfish, which have higher protein, calcium, iron, and zinc content than other fish. However, the 210Po value does not significantly correlate with other parameters, such as bathymetry, current, or sea surface temperature.

Environmental evaluation of radioactivity levels and associated radiation hazards in groundwater around the WIPP site

Groundwater may contain radioactive substances which can be dangerous to human health. Concentrations of natural radionuclides polonium (Po), thorium (Th), uranium (U), and radium (Ra) isotopes were measured in groundwater samples collected from different locations in the vicinity of the Waste Isolation Pilot Plant (WIPP) site in Carlsbad, New Mexico. The average values of gross activity concentrations of 210Po, 228Th, 238U, 234U, 226Ra and 228 Ra isotopes were determined to be 1.62 Bq L-1 in shallow groundwater and 5.88 Bq L-1 in deep groundwater, respectively. The total radioactivity in deep groundwater was higher than that in shallow groundwater, and most of the radioactivity in the water is from 226Ra. Furthermore, the effective doses for ingestion of natural radionuclides were about 0.333 mSv y−1 for shallow groundwater and about 1.338 mSv y−1 for deep groundwater samples, which are higher than the World Health Organization (WHO, 2017) guideline level (0.1 mSv y−1) for drinking water. Ra dominated the total ingestion dose, contributing 93.06 % and 75.40 % of the total effective doses to the deep and shallow groundwater, respectively. The ingrowth and decay of natural radionuclides suggested that 228Ra/226Ra ratio can be a useful indicator of the source of radioactive contamination. The radioactivity data obtained from the investigated groundwater samples can be used to establish a baseline for radioactivity levels in groundwater around the WIPP site.

Natural radioactivity and element characterization in pit lakes in Northern Sweden.

Northern Sweden has been the object of intense metal mining in the last decades producing several water-filled open-pits, or pit lakes. Most of these pit lakes have been limed to maintain a good water quality and to prevent generation of acidic water that could leach the exposed rocks and release metals into water. The aim of this work was to examine the concentration of stable elements and naturally occurring radionuclides in water and sediment samples from pit lakes originating from non-uranium mining activities in Northern Sweden. Surface water and surface sediments were collected from 27 pit lakes in Northern Sweden. Water quality parameters, concentration of stable elements and radionuclides were measured by a water probe, ICP-MS and XRF, and alpha and gamma spectrometry, respectively. Furthermore, a multivariate statistical analysis (PCA) was performed on the water samples and sediments. In general, the quality of the surface water was good, but some lakes had low pH values (2.5–5.7), and high concentrations of Fe (up to 200 mg/L) and other metals (e.g. Zn, Cu). When relating the metal concentrations in sediments in pit lakes with the concentration found in natural lakes, some sites had relatively high levels of Cu, As, Cr and Pb. The activity concentration of 210Po, and U and Th isotopes in water and sediment samples were at environmental levels, as was the ambient dose equivalent rate at these sites (range 0.08–0.14 μSv/h).

Estimation of the Annual Effective Dose Due to the Ingestion of 210Pb and 210Po in Crops from a Site of Coal Mining and Processing in Southwest China.

The exploitation of mineral resources may cause the environmental release of radionuclides and their introduction in the human trophic chain, affecting public health in the short and long term. A case study of the environmental radiation impact from coal mining and germanium processing was carried out in southwest China. The coal mines contain germanium and uranium and have been exploited for more than 40 years. The farmlands around the site of the coal mining and germanium processing have been contaminated by the solid waste and mine water to some extent since then. Samples of crops were collected from contaminated farmlands in the research area. The research area covers a radius of 5 km, in which there are two coal mines. 210Pb and 210Po were analyzed as the key radionuclides during the monitoring program. The average activity concentrations of 210Pb and 210Po in the crops were 1.38 and 1.32 Bq/kg in cereals, 4.07 and 2.19 Bq/kg in leafy vegetables and 1.63 and 1.32 Bq/kg in root vegetables. The annual effective doses due to the ingestion of 210Pb and 210Po in consumed crops were estimated for adult residents living in the research area. The average annual effective dose was 0.336 mSv/a, the minimum was 0.171 mSv/a and the maximum was 0.948 mSv/a. The results show that the crops grown on contaminated farmland contained an enhanced level of radioactivity concentration. The ingestion doses of local residents in the research area were significantly higher than the average level of 0.112 mSv/a in China, and the world average level of 0.042 mSv/a through 210Pb and 210Po in crop intake, respectively.

Radioecological studies of the main naturally occurring radionuclides in the area of Gela Phosphate Industry (Italy) through radioanalytical separation and measurement techniques

Radioecological studies have been carried out in area of Gela Phosphate Industry. As a part of the project, some achievements have been described in the paper, including: (1) determination of the activity concentrations of 210Po, 210Pb, uranium, and radium isotopes in phosphogypsum, phosphoric acid, soil, and marine sediment, (2) inventory estimation of the NORM in the residual product and by-product, and (3) the radioecological investigation and evaluation on the NORM contamination in the sea area of Gela. The obtained data showed that the 210Po, 210Pb, uranium, and radium isotope contamination due to discharge of phosphogypsum from 1960s to 1990s is not observable through sediment analyses.