210Po in the marine biota of Korean coastal waters and the effective dose from seafood consumption

Radiological hazard assessment of 210Po in freshwater mussels (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata) in Vietnam

210Po is a significant source of ionizing radiation that people are exposed to through food globally. This paper presents the wide range of accumulation level of 210Po in the organs of two species of shellfish including freshwater mussel (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata), common freshwater species in Vietnam. There was a significant correlation between 210Po activity in muscle to their mass and size of freshwater mussels. In contrast, there was no relation between other organs of both species with their mass and size. The annual effective dose due to consumption of freshwater mussels ranged from 68.7 to 291 μSv year-1 with a mean value of 138 μSv year-1 for muscle and from 321 to 4560 μSv year-1 with a mean value of 1422 μSv year-1 for the hepatopancreas. Meanwhile, the AED for golden apple snail was recorded to be higher with values ranging from 105 to 2189 μSv year-1 with mean value of 673 μSv year-1 for muscle and from 468 to 4155 μSv year-1 with a mean value of 2332 μSv year-1 for hepatopancreas. Thus, the consumption of these two types of shellfish is considered relatively safe, but the hepatopancreas gland must be removed before processing.

A review of natural and anthropogenic radionuclide pollution in marine bivalves

Radionuclide contamination in food is a public health issue. Bivalves are known to accumulate relatively high levels of radionuclides. Despite many relevant reports, this information is poorly organized. Therefore, in this study, we conducted a comprehensive scientific review of radionuclides in marine bivalves. In general, the accumulation of radionuclides in bivalves is highly species and tissue-specific, which may be due to the different biological half-life of radionuclides in different species and tissues. The trophic pathway is the main pathway for the accumulation of most radionuclides in bivalves, with polonium-210 (210Po) and lead-210 (210Pb) potentially selectively accumulating in the digestive glands, while 134Cs and 137Cs selectively accumulating in the adductor muscle and mantle. Some other radionuclides (radium-226 (226Ra) and strontium-90 (90Sr)) are absorbed along with other minerals (e.g. Calcium) and selectively accumulate in bivalve shells. The information in this study can provide an overview of radionuclide contamination in marine bivalves.

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).

Radionuclide contents in sediment and seafood from Makoko Lagoon, Lagos State, Nigeria

Sediment and seafood samples were collected from Makoko Lagoon, Lagos state, Nigeria. Gamma-ray spectrometry was used to determine the activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th in the samples. The average activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th in the sediment were 41.04 ± 6.41, 10.15 ± 3.19 and 4.39 ± 2.10 Bq kg^-1, respectively, while the annual effective dose was 0.01 mSv/year. In seafood, the average activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th were 15.66 ± 8.07, 1.72 ± 1.51 and 1.93 ± 0.30 Bq kg^-1, respectively. The cumulative effective ingestion dose obtained ranged from 0.016 μSv/year (giant prawn) to 1.08 μSv/year (Parrotgrunt). The mean activity concentrations and absorbed dose rate in sediment were below the worldwide average values. The cumulative dose from the ingestion of seafood was also significantly low. Sediment and seafood from the lagoon in Makoko pose no health risk from a radiological point of view to the population.

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.

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.

Evaluation of the radiological dose due to 210Po in commercial clupeid fish collected in the near-shore environment of the high background natural radiation area (HBNRA) on the southwest coast of India

In this study, we quantified the tissue concentration of ²¹⁰Po in a variety of commercial sardine fish species of the family Clupeidae from an area of high background natural radiation area on the southwest coast of India. The smooth belly sardine Amblygaster leiogaster had the lowest ²¹⁰Po concentration in its muscle (45.6 ± 7.9 Bq kg^-1 fresh), while the goldstripe sardine Sardinella gibbosa had the highest (103.4 ± 10.1 Bq kg^-1 fresh). The Annual Committed Effective Dose (ACED) of fried sardine and sardine curry were 134.3-304.3 μSv y^-1 and 226.6-513.5 μSv y^-1, respectively. Of the ²¹⁰Po loss, 20 % was due to frying and 10 % to preparing sardine curry. The effective dose was found to be globally comparable and well below the world limit. Consumption of sardines containing ²¹⁰Po would not pose a health hazard to the residents of Manavalakurchi.

Background 210Po activity concentrations in Greenland marine biota and dose assessment

Polonium-210 (²¹⁰Po) is a radionuclide sentinel as it bioaccumulates in marine organisms, thereby being the main contributor to committed dietary doses in seafood consumers. Although seafood and marine mammals are an important part of the traditional Inuit diet, there is a general lack of information on the ²¹⁰Po concentrations in the Greenlandic marine food chain leading to the human consumer. Here, we determine background ²¹⁰Po concentrations in edible parts of different marine organisms from Greenland and provide a dose assessment. Blue mussels (Mytilus edulis), organs of ringed seal (Pusa hispida) and polar bear (Ursus maritimus) displayed significantly elevated ²¹⁰Po concentrations in respect to all other studied organisms (p < 0.001). ²¹⁰Po concentrations ranged from 0.02 Bq kg^-1, w.w. in Greenland halibut (Reinhardtius hippoglossoides) muscle to 78 Bq kg^-1, w.w. and 202 Bq kg^-1, w.w. in ringed seal muscle and kidneys, respectively. ²¹⁰Po concentration ratio for edible parts increases in the order bladderwrack (Fucus Vesiculosus), northern shrimp (Pandalus borealis), blue mussels, and from fish species to ringed seal and polar bear. ²¹⁰Po distribution in fish, ringed seal, and polar bear follows a general pattern, the lowest concentrations were in muscle, and the highest concentrations were in the organs involved in metabolism. The derived ²¹⁰Po annual absorbed dose in edible parts of studied marine organisms are several orders of magnitude lower than the recommended dose rate screening value of 10 μGy h^-1. Effective doses from intake of ²¹⁰Po to Greenland average children (1.4 mSv y^-1), and high seafood and marine mammal consumers (2 mSv y^-1 for adults and 3.6 mSv y^-1 for children) are higher than the world average annual effective dose due to ingestion of naturally occurring radionuclides.

Distribution, annual committed effective dose, and health safety assessment of 210Po in marine biota from Kalpakkam coast, Bay of Bengal

Seafood, intertidal biota, beach sediment, and seawater from Kalpakkam coast, Bay of Bengal were analyzed for ²¹⁰Po to evaluate the internal exposure and other radiological safety aspects. Kalpakkam houses various nuclear power generation facilities on its coast. The activity concentration of ²¹⁰Po was more pronounced in the intertidal organisms. Pelagic planktivorous fishes have the highest activity of the non-technogenic radionuclide, followed by the detrital feeders, benthic planktivores, benthic carnivores, and pelagic carnivore fishes. The affinity of ²¹⁰Po to organic detrital matter and planktonic organisms has led to a higher accumulation of radionuclide in planktivorous fishes. Activity concentration of ²¹⁰Po in seafood ranged between 1.13 ± 0.3 and 96.71 ± 1.6 Bq kg^-1 (Becquerel/kilogram). In seaweeds and gastropods, it ranged from 2.09 ± 0.2 to 8.21 ± 0.6 and from 9.31 ± 0.7 to 21.58 ± 1.2 Bq kg^-1, respectively. The committed effective dose (CED) of ²¹⁰Po in seafood varied from 31.18 to 456.68 μSv yr^-1 (microSievert/year). Radiological hazard parameters, such as activity intake, CED in consumption, of the seafood from this coast are within the acceptable levels prescribed by the International Commission on Radiological Protection and US Environmental Protection Agency.

Correlation of phytoplankton satellite observations and radiological doses in molluscs

In this work data of salinity, temperature, suspended particulate matter (SPM), chlorophyll-a, and phytoplankton concentration in the Gibraltar Strait coast, in the confluence of the Mediterranean Sean and the Atlantic Ocean, were analyzed together with ²¹⁰Po, ⁴⁰K, ²¹⁰Pb and ²³⁴Th activity concentration in different types of bivalve molluscs at the same time-period. The physicochemical parameters were evaluated using the Copernicus Marine Environment Monitoring Service (CMEMS) products based on satellite observations. A multivariate statistical analysis, including contrasted natural radioactivity contents, allowed the discrimination of bivalve molluscs from Atlantic and Mediterranean coasts. Additionally, a cluster analysis determined a highly significant negative correlation ²¹⁰Po concentration in molluscs and phytoplankton concentration suggesting that phytoplankton concentration in the water column is a determinant factor to regulate ²¹⁰Po concentration in those animals. These results introduce a useful tool to calculate the radiological doses in seafood from chlorophyll satellite image.

Distribution and annual committed effective dose assessment of 210Po in popular marine species at the near-shore Binh Thuan province, Vietnam

²¹⁰Po concentration in thirty popular marine species (twenty five fishes, four bivalves and one crab) with different habitats, feeding types, and trophic levels at the near-shore Binh Thuan, Vietnam was analyzed using the alpha detectors. The ²¹⁰Po activities were widely ranged from 3.07 ± 0.18 in a fish species (Bumpnose trevally) to 78.6 ± 5.3 Bq/kg w.w in a bivalve species (Green mussel) with the average value of 16.6 Bq/kg w.w. The results showed that the species with lower trophic level value have higher ²¹⁰Po concentration. Regarding the feeding types, the ²¹⁰Po concentration in the omnivorous species is about 2.9 times higher than in the carnivorous species. The species living in demersal zone accumulated a high ²¹⁰Po in comparison with species living in reef-associated and pelagic-neritic zones. The calculated annual committed effective dose from ²¹⁰Po due to the ingestion of seafood from demersal zone and bivalve species of the area was significant high.

Levels and Distributions of 210Pb and 210Po in Selected Seafood Samples in China and Assessment of Related Dose to Population

In this study, the activity concentrations levels of 210Pb and 210Po in the edible portions of eight seafood samples collected from the Fujian coast of China were determined. The activity concentrations ranged from 0.74 ± 0.08 to 12.6 ± 1.0 Bq/kg for 210Po and from the minimum detectable limit (MDL, 0.80 Bq/kg) to 11. 7 ± 1.1 Bq/kg for 210Pb. The 210Po activity concentration in all the fish organs ranged from 0.68 to 204 Bq/kg (w.w.), and the 210Po activity was mainly concentrated in the stomach, spleen, heart, liver, gonad, and intestine samples. The 210Pb activity concentration in all the fish organs ranged from the MDL to 15.2 Bq/kg (w.w.), and the 210Pb activity was concentrated in the head, fish scale, and gill samples. The annual effective ingestion doses ranged from 82.8 to 255 μSv/a for all age groups, and the lifetime risk of cancers were estimated. Both the effective ingestion doses and cancer risk to humans were within the acceptable ranges.

Assessment of the annual committed effective dose due to the 210Po ingestion from selected sea-food species in Vietnam

Activity concentration of ²¹⁰Po in the edible muscle tissues of twelve sea-food species (the most common marine food consumed of population in Vietnam) were analyzed using the PIPS detectors ORTEC Alpha-Ensemble spectrometer. The ²¹⁰Po activity concentration in studied samples was found to vary from 0.82 ± 0.47 to 70.3 ± 8.5 Bq/kg fresh weight. The highest activity concentration was recorded for the Blood cockle (Anadara granosa) and the lowest for Silver pomfret (Pampus argenteus). The annual committed effective dose (CED) of ²¹⁰Po to humans (the local residents) due to ingestion of each studied species was calculated from 18.5 to 1586 μSv/y. The average annual committed effective dose value was reported 394 μSv/y, which is marginally higher than the average CED contributed from ingestion of food and water total in global background (290 μSv/y).

Activity concentrations of 210Po and 210Pb in fish and mussels in İzmir, Turkey, and the related health risk assessment (dose assessment and pesticide levels) to the consumers

The activity concentrations of natural radionuclides (²¹⁰Po and ²¹⁰Pb) and residual pesticide levels were determined from the fish (red mullet, common sole, anchovy, horse mackerel, gray mullet, and sardine) and mussel samples collected in İzmir Bay seasonally from October 2012 and July 2013. The ²¹⁰Po and ²¹⁰Pb concentrations varied between 5.7 ± 4.0 Bq kg^-1 dry weight (dw) to 353.7 ± 45.0 Bq kg^-1(dw) and 0.7 ± 0.2 Bq kg^-1 (dw) to 4.3 ± 0.8 Bq kg^-1 (dw), respectively. From a public health point of view, the fish and mussel collected from the İzmir Bay are not harmful to consumers.

Distribution of 239,240Pu in marine products from the seas around the Korean Peninsula after the Fukushima nuclear power plant accident

In March 2011, an earthquake caused the shutdown of the active reactors at the Fukushima Daiichi Nuclear Power Plant (NPP), with the succeeding tsunami resulting in the release of radioactively contaminated water into the adjacent Japanese coastal waters. Marine biota selected from various trophic levels were collected in Korean coastal waters throughout 2014 and 2015 and their plutonium levels were measured to evaluate the radioactive contamination levels in the marine organisms that constitute the primary seafood diet in the Republic of Korea (ROK). The results showed that the activity concentrations of ^239,240Pu in plankton, macroalgae, mollusks, crustaceans, and cephalopods ranged from 13 to 58, 0.64 to 0.80, 0.94 to 5.40, 0.06 to 0.50, and 0.26 mBq kg^-1 of wet weight (w.w.), respectively. The activity concentrations of ^239,240Pu measured in the muscles of fish varied from 0.09 to 0.30 mBq kg^-1 (w.w.), relatively low values compared to those in other groups regardless of fish species, size, and sampling area. The concentration characteristics of ^239,240Pu in the various organs in the respective marine products revealed that the internal organs showed higher concentrations than the muscle or skin (or exoskeleton). The highest concentration of ^239,240Pu was measured in the viscera of an abalone, which had an activity concentration of 6.31 mBq kg^-1 (w.w.). The concentration factors (CFs) in the >300-μm fraction of plankton and in anchovy, shrimp, and mackerel ranged 67-84% of the International Atomic Energy Agency (IAEA)-recommended values, although the CF in macroalgae was much lower at approximately 5% of IAEA values, suggesting a wide range of ^239,240Pu CF in macroalgae. The mean transfer factor (TF) between macroalgae (0.6-0.8 mBq kg^-1) and abalone (5.4 mBq kg^-1) was estimated to be 7.5, implying that effective Pu transfer occurred between the two species. These figures equate to annual effective doses of ^239,240Pu to Koreans through consumption of macroalgae, shellfish, and fish of 1.8 × 10^-6, 1.4 × 10^-6, and 7.1 × 10^-7 mSv yr^-1, respectively, and a total dose of 3.9 × 10^-6 mSv yr^-1, values that are negligible compared to the annual effective dose limit of 1 mSv yr^-1.

Spatial variability in Polonium-210 and Lead-210 activity concentration in New Zealand shellfish and dose assessment

The activity concentrations of Polonium-210 (²¹⁰Po) and Lead-210 (²¹⁰Pb) were determined in shellfish (Perna canaliculus and Paphies subtriangulata) sampled bimonthly from March 2018 to February 2019 from 14 sites around New Zealand. Activity concentrations of ²¹⁰Po ranged from 4.7 ± 1.1 to 324 ± 17 Bq. kg^-1 with a mean value of 57 ± 72 Bq. kg^-1 (wet weight). The activity concentrations of ²¹⁰Pb were lower than those for ²¹⁰Po (0.1 ± 0.4 and 1.9 ± 0.4 Bq. kg^-1, with a mean value of 0.7 ± 0.4 Bq. kg^-1, wet weight). The calculated ²¹⁰Po/²¹⁰Pb activity concentration ratios were higher than unity in all samples indicating that radionuclides are not in equilibrium in shellfish and most of the ²¹⁰Po was unsupported by its grandparent ²¹⁰Pb. No significant difference was noted in ²¹⁰Po activity concentration between different seasons, species or shellfish condition index. Significant spatial variability in ²¹⁰Po activity concentration was observed with elevated ²¹⁰Po activity concentration in two sampling sites: Ninety Mile Beach (mean 257 ± 47 Bq. kg^-1) and Maunganui Bluff (mean 127 ± 22 Bq. kg^-1). Elevated ²¹⁰Po is hypothesised to be related to an increase of ²¹⁰Po accumulation through diet. Individuals who consume large quantities of shellfish (10 g per day or more) from areas affected by elevated ²¹⁰Po activity concentration may be exposed to an annual committed effective dose from ²¹⁰Po in shellfish in excess of 1 mSv.

A REVIEW ON 210Po AND 210Pb IN INDIAN SEAFOOD AND DOSE TO CONSUMERS

India is the second largest seafood producer in the world marketing more than 7000 edible species. In this regard, commendable studies have been conducted since the 1970s by different research groups and more data are reported. In this work, all the studies on 210Po and 210Pb measurements in abiotic and biotic components of India have been combined and reviewed. The concentrations of 210Po and 210Pb are estimated by radiochemical separation followed by alpha counting. Grain size, season, Tsunami waves and place of sampling have a decisive bearing on 210Po and 210Pb concentration in abiotic components. Plankton shows a higher Kd factor (104) compared to seaweeds and sea grass (103). Pond ecosystems recorded the highest Kd factor (4·3 × 104) compared to other freshwater and marine ecosystems. Bioaccumulation of 210Po and 210Pb varies with respect to variety of seafood. The committed effective dose (CED) calculated for shellfish species maintained a higher range of 2.5 × 10-2 mSv/y to 9.8 × 10-1 mSv/y and for fish species fluctuated from 3.8 × 10-4 mSv/y to 2.0 × 10-1 mSv/y. The studies conducted so far are scattered, and need to be gathered for future reference and planning (i.e. There is not much information available for Kerala, Karnataka, Maharashtra, Gujarat, Andhra, West Bengal and Odessa coast). Therefore, it is strongly recommended that further and more complete research is undertaken to study the bioaccumulation of 210Po and 210Pb from seafood. Overall, the present review concludes that Indian seafood is radiologically safe.

Levels of radionuclide concentrations in benthic invertebrate species from the Balearic Islands, Western Mediterranean, during 2012-2018

Baseline levels of radionuclides in the marine environment of the Balearic Islands in Western Mediterranean have not been reported in literature. Because of their ecological role and acknowledged sensitivity to pollutants, herein, the activity concentrations of ²¹⁰Po, ⁴⁰K, ²¹⁰Pb, ⁹⁰Sr, and ²³⁴Th were measured in two types of benthic invertebrate species (mussels and sea urchins) sampled during 2012-2018. The activity concentrations of ²¹⁰Po, ⁴⁰K, ²¹⁰Pb, and ²³⁴Th ranged from 38 ± 1 to 325 ± 11 Bq kg^-1 dry weight (d.w.), 220 ± 10 to 996 ± 46 Bq kg^-1 d.w., ND (lower than the limit of detection) to 55 ± 8 Bq kg^-1 d.w., and ND to 70 ± 15 Bq kg^-1 d.w., respectively. In all cases, no artificial ⁹⁰Sr activity was detected in the collected samples. The committed effective dose to humans was calculated to be in the range of 48-640 μSv year^-1.

Distribution and accumulation of artificial radionuclides in marine products around Korean Peninsula

We investigated the distributions of the artificial radionuclides ¹³⁷Cs, ^239+240Pu, and ⁹⁰Sr in the various marine products around Korean Peninsula collected in 2015-2017. The activities of ¹³⁷Cs, ^239+240Pu, and ⁹⁰Sr were in the ranges of 12.2-258.4 mBq kg^-1, 0.014-1.879 mBq kg^-1, and 11.3-18.3 mBq kg^-1, respectively. The higher ^239+240Pu (a factor of 10-50) relative to fishes were observed in mollusks. ¹³⁷Cs in fishes were significantly enriched with growths. The calculated concentration factors (CFs) of ¹³⁷Cs, ^239+240Pu, and ⁹⁰Sr in marine products were 7-143, 3-407, and 15-25, respectively. Overall, no noticeable artificial radioactivity was detected in marine organisms when comparing these results with previous data reported before the Fukushima nuclear accident and recommended CF values. The annual effective doses of ¹³⁷Cs, ^239+240Pu, and ⁹⁰Sr by seafood consumption in South Korea were estimated to be 1.1 × 10^-4, 1.6 × 10^-5 and, 2.9 × 10^-5 mSv yr^-1, respectively, which is insignificant relative to that of natural radionuclides.

Natural radioactivity in algae arrivals on the Canary coast and dosimetry assessment

Nowadays, the use of wild and culture harvest seaweed in food industry is a booming productive sector. In this context, a radiological characterization of five globally common seaweed species that were collected in arrival on Gran Canaria coast was carried out. The studied algae species were Cymopolia barbata, Lobophora variegata, Sargassum vulgare, Dictyota dichotoma and Haliptilon virgatum. Radionuclides analysed by alpha and gamma spectrometry were ²³⁸U, ²³⁴U, ²³⁵U, ²¹⁰Po, ²³⁴Th, ²²⁶Ra, ²¹⁰Pb, ²²⁸Th, ²²⁴Ra, ⁴⁰K and ⁷Be. Activity concentrations, ratios, and concentration factors (CF) were determined for all samples collected. The CF in algae was higher for reactive-particle radionuclides (²¹⁰Po, ²³⁴Th, ²²⁸Th and ²¹⁰Pb) than for conservative ones (⁴⁰K and the uranium isotopes). ²¹⁰Po, ²²⁸Th and ²³⁴Th CF were one or two orders of magnitude higher than those recommended by the IAEA. L. variegata, C. barbata and S. vulgare showed a clear preference for ²¹⁰Pb and ²¹⁰Po, for uranium radioisotopes, and for ⁴⁰K and ²³⁴Th, respectively. A dosimetry assessment due to seaweed ingestion showed considerable values of annual committed effective dose for H. virgatum (605 ± 19 μSv/y), L. variegata (574 ± 17 μSv/y) and D. dichotoma (540 ± 30 μSv/y). Hence, this study suggests that an algae radiological characterization is recommended as part of the product valorising process.

Assessment of the committed effective dose due to the 210Po intake from fish consumption for the Arabian Gulf population

This study aims to assess the committed effective dose due to the intake of ²¹⁰Po from the consumption of fish in Arabian Gulf countries. Twenty different kinds of fish, which represent the most common fish species consumed in the Arabian Gulf countries, were analyzed using alpha spectrometer technique. ²¹⁰Po activity concentrations in fish samples were found to vary over a wide range from 0.1 to 14.7 Bq kg^-1 fresh weight. This variation of ²¹⁰Po concentrations between various type of fish samples might be attributed to the feeding type pattern and the size of fish. The annual committed effective dose due to ingestion of ²¹⁰Po in fish species for adults in the Arabian Gulf countries was estimated and found to vary from 38 μSv in Bahrain to 85 μSv in Oman with an average value of 59 μSv. These values are considered relatively high compared to those reported in some other regions. However, it is still much lower than the world average ingestion dose due to natural radiation sources.

Radiation Doses From the Norwegian Diet

Ingestion doses between and within countries are expected to vary significantly due to differences in dietary habits and geographical variations in radionuclide concentrations. This paper presents the most comprehensive assessment to date of the effective radiation dose from the Norwegian diet, from natural as well as anthropogenic radionuclides. Ingestion doses to the Norwegian public are calculated using national dietary statistics and the most relevant radionuclide concentration data for the various food products. The age-weighted average effective dose received by the Norwegian population from the diet is estimated at 0.41 mSv y from naturally occurring radionuclides and 0.010 mSv y from anthropogenic radionuclides. This is approximately 50% higher than the estimated world average. Fish and shellfish is the food group that provides the largest dose contribution from the average Norwegian diet. Although the average dose from anthropogenic radionuclides today is low, the exposure may still be significant for certain critical groups-especially persons who consume large amounts of reindeer meat from the regions that received significant radioactive fallout after the Chernobyl accident. Furthermore, persons with high Rn concentrations in their drinking water are among those receiving the highest ingestion doses in Norway.

Baseline activity concentration of 210Po and 210Pb and dose assessment in bivalve molluscs at the Andalusian coast

In this study, the activity concentrations of ²¹⁰Po and ²¹⁰Pb were determined in different types of bivalve molluscs sampled during the period of May 2014-June 2015 along the Andalusian littoral. Radioactivity concentrations of ²¹⁰Po were determined through alpha-particle spectrometry using ²⁰⁹Po as an internal tracer. Radioactivity concentrations of ²¹⁰Pb were determined through low-level gamma-ray spectrometry. The activity concentrations of ²¹⁰Po and ²¹⁰Pb varied between 40 ± 2 and 515 ± 9 Bq kg^-1 dry weight (d.w.), and ND (lower than limit of detection) and 73 ± 10 Bq kg^-1 d.w., respectively. The committed effective dose to humans was calculated to range from 39 to 477 μSv year^-1. Radioactivity and dose levels were compared with previous studies from other countries.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.