Biodistribution of naturally occurring radionuclides and radiocesium in wild European perch (Perca fluviatilis).

Wild European perch (Perca fluviatilis) is one of the most important freshwater fish species, in Sweden, due to its widespread and his value for recreational fishing. Little it is known regarding the biodistribution of naturally occurring radionuclides such as 238U, 234U, 226Ra, 210Po in perch. Therefore, in this study, perches from five lakes located in different counties in Sweden were collected to investigate the biodistribution of 238U, 234U, 226Ra, 210Po and 137Cs in organs and tissues of perch as well as their radiological impact. The results showed that uranium radionuclides ranged between 0.1 and 6 Bq/kg with an average value of 1.1 ± 1.5 Bq/kg. 226Ra varied from 0.4 to 8 Bq/kg with a mean concentration of 1.7 ± 1.9 Bq/kg. The ranged of 210Po was 0.5 - 250 Bq/kg, with an average value of 24 ± 52 Bq/kg. On the other hand, the highest activity concentration of 137Cs, 151 ± 1 Bq/kg, was detected in muscle samples of perch from Redsjösjön lake. For uranium radionuclides and 226Ra uptake from water is the main source whereas for 210Po and 137Cs the uptake is controlled by the perch diet. Regarding naturally occurring radionuclides, the perch tended to accumulated uranium radionuclides in fins, gills, and skin; 226Ra in bones, fins and skin and 210Po in the organs linked to digestive system. Finally, in case of consumption, it is advised the consumption of skinned fillets of perch due to the higher bioaccumulation of the radionuclides investigated in the skin and scales.

PSCF and CWT methods as a tool to identify potential sources of 7Be and 210Pb aerosols in Granada, Spain.

This research is focused on studying the preferred source regions and the pathways of the air masses with high particulate concentrations impacting on the activity concentrations of 7Be and 210Pb aerosols in Granada atmosphere. For this purpose, three different source-receptor methods have been used: Cluster Analysis, Potential Source Contribution Function (PSCF), and Concentration Weighted Trajectory (CWT). Air filter samples were weekly collected and analysed in Granada university (Spain 37.177N, 3.598 W, 687m a.s.l.) during 12 years (2006-2017) for the activity concentration of 7Be, and during 5 years (2010-2014) for the one of 210Pb. The time series of the collected data indicate that the concentration of both radiotracers present a cyclical and seasonal pattern, in association with their origins and atmospheric conditions. Clustering analysis showed that the air masses arriving to Granada can be classified as: (1) tropical continental air masses coming from the Mediterranean Sea, (2) tropical and warm polar maritime air masses produced over the Atlantic Ocean, and (3) continental air masses originated over Europe and Northern Africa. The PSCF and CWT methods confirmed that the main source areas of 7Be are located in the Atlantic coast of southern Morocco, and Northern Africa. On the other hand, southern France and the Algerian desert were found to be the main region sources of 210Pb. In addition, the Mediterranean Basin has been postulated as a strong source region for 7Be and 210Pb. Furthermore, the PSCF and CWT models show that the regions with larger 7Be/210Pb ratios are located in the Atlantic Ocean, due to frequent stratospheric intrusions specially during the winter months.

Uranium content and uranium isotopic disequilibria as a tool to identify hydrogeochemical processes.

This paper studies the uranium content and uranium isotopic disequilibria as a tool to identify hydrogeochemical processes from 52 groundwater samples in the province of Granada (Betic Cordillera, southeastern Spain). According to the geological complexity of the zone, three groups of samples have been considered. In Group 1 (thermal waters; longest residence time), the average uranium content was 2.63 ± 0.16 µg/L, and 234U/238U activity ratios (AR) were the highest of all samples, averaging 1.92 ± 0.30. In Group 2 (mainly springs from carbonate aquifers; intermediate residence time), dissolved uranium presented an average value of 1.34 ± 0.13 µg/L, while AR average value was 1.38 ± 0.25. Group 3 comes from pumping wells in a highly anthropized alluvial aquifer. In this group, where the residence time of the groundwater is the shortest of the three, average uranium content was 5.28 ± 0.26 µg/L, and average AR is the lowest (1.17 ± 0.12). In addition, the high dissolved uranium value and the low AR brought to light the contribution of fertilizers (Group 3). In the three groups, 235U/238U activity ratios were similar to the natural value of 0.046. Therefore, 235U detected in the samples comes from natural sources. This study is completed with the determination of major ions and physicochemical parameters in the groundwater samples and the statistical analysis of the data by using the Principal Component Analysis. This calculation indicates the correlation between uranium isotopes and bicarbonate and nitrate anions.

NATURAL RADIUM ISOTOPES PRESENT IN SOME COSMETIC PRODUCTS: DETERMINATION OF ACTIVITY CONCENTRATION AND DOSE ESTIMATION.

Since the early days, clays, plant extracts and raw materials have been used for therapeutic and beauty purposes. Nowadays, this use is widely spread, as a huge amount of companies have developed new cosmetics based on natural sources. This may lead to an accumulation of radionuclides that can be hazardous for people. Especially dangerous are radium isotopes (226,228Ra), which can be part of the raw materials that cosmetics are made from. In this paper, the concentration of radium isotopes of 18 natural cosmetics was determined. Concentrations resulted in the range 7.9 ± 5.0-37.6 ± 12.5 Bq kg-1 for 226Ra; and 2.5 ± 1.7-35.4 ± 2.6 Bq kg-1 for 228Ra. The effective dose in the skin has been estimated, obtaining a mean value of 13.1 ± 4.9 µSv y-1. This value is far from the reference level of 50 mSv y-1 for the public members. Therefore, no radiological risk derived from the use of these samples, has been found.

7Be spatial and temporal pattern in southwest of Europe (Spain): Evaluation of a predictive model.

This study presents a comprehensive statistical analysis of the cosmogenic radioisotope 7Be measured in surface air in ten stations over Spain for a 9 years period (from January 2006 to December 2014). Besides the analysis of 7Be seasonal and inter-annual variability, 7Be frequency distributions and its correlations with meteorological variables observed in the 10 sampling sites were investigated. The second part of this paper focuses on a feasibility study for the application of the Artificial Neural Networks (ANNs) to predict monthly 7Be activity concentrations using meteorological variables, PM10 concentrations and the sunspot number as input parameters. Notwithstanding the low correlations found between 7Be and input parameter, the performance of the ANNs, as evaluated by the relevant statistical parameters, demonstrates their capability to correctly predict 7Be monthly activities in the 10 Spanish sampling sites.

DETERMINATION AND DOSE CONTRIBUTION OF URANIUM ISOTOPES AND 210Po ACTIVITY CONCENTRATIONS OF NATURAL SPRING WATERS IN THE PROVINCE OF GRANADA, SPAIN.

The activity concentrations of alpha-emitters comprising isotopes of uranium (238, 234, 235U) and polonium (210Po) were measured using alpha-particle spectrometry in natural spring waters in the province of Granada, Spain. These water are consumed by the population of the zone who live in villages. This is almost half of the population of the whole region. Mean values of activity concentrations found are 42.61 ± 2.66; 49.55 ± 3.03; 1.64 ± 0.28 and 1.74 ± 0.15 mBq L-1 for 238U, 234U, 235U and 210Po, respectively. Finally, the radiological impact of the analysed waters has been determined, in terms of the estimation of the committed annual effective dose due to the ingestion of the water. The assessment has been carried out for five age groups with the aim to cover all the population. The calculated annual effective doses are observed to be below the prescribed dose limit of 100 µSv y-1 recommended by WHO.

Impact of air masses on the distribution of 210Pb in the southeast of Iberian Peninsula air.

The current research has been developed in the southern of the Iberian Peninsula in order to better understand the atmospheric processes and also the influence of the air masses origin and pathways in the transport of 210Pb-aerosols in the atmosphere. Simultaneous measurements of the radionuclides 7Be and 210Pb on airborne have been routinely carried out at Granada (Spain 37.177N, 3.598 W, 687 m a.s.l.) from 2010 to 2014. The long term monitoring evolution on 210Pb is discussed in this study and also the useful ratio 7Be/210Pb. The maximum monthly activity concentration for 210Pb at ground level in Granada was detected during summer and early autumn (September), whereas minimum activity was measured in the winter. The monthly mean activity concentration for 210Pb was 617.8 ± 33.0 µBq·m-3. The results show that the annual average 210Pb concentrations in samples collected during the same period were almost constant. The lowest activity concentration for 210Pb are associated with maritime air masses coming from Atlantic and Norwest of Spain, while the highest activity concentrations for this radiotracers were positively correlated with the arrival of mineral dust linked to continental air masses coming from Mediterranean, Africa and Local area. The concentrations values show a nice agreement with the relevant reported results.

A cluster analysis of back trajectories to study the behaviour of radioactive aerosols in the south-east of Spain.

This research is focused on the study of the influence of the air masses together with the local meteorological fluctuations on the amount of radioactive elements in aerosols at surface air of the southeastern of Iberian Peninsula. The radioactivity in aerosols has been determined by measuring the concentration activity of Gross ß and (7)Be from January 4(th), 2011 to December 31(s)(t), 2013. The activity concentration (Bq/m(3)) of gross beta was measured by α/ß Low-Level counter, whereas the activity concentration of (7)Be (Bq/m(3)) was detected by gamma spectrometry (Eγ = 477.6 KeV, Yield = 10.42%). The air mass origings have been set using k-means clustering analysis of daily 72-h kinematic 3D backward trajectories at 500 m, 1500 m and 3000 m of altitude. Finally, a multiple Regression Analysis (MRA) have been carried out in order to determine the influence of the origins and trajectories of the air masses and local meteorology variations on the evolution of Gross ß and (7)Be activity concentration. In conclusion, the results of the current research demonstrate that the re-suspended mineral dust from Northern Africa transported by Mediterranean air masses at low altitude (500 m) and African air masses at high altitude (3000 m) increases the radioactivity concentration in aerosols at the surface atmosphere. In addition, the opposite influence of the Saharan intrusions at 1500 m of altitude on the behaviour of (7)Be aerosols deserves special attention.

Discharges of nuclear medicine radioisotopes in Spanish hospitals.

Given the increasing use of radiopharmaceuticals in medicine, the aim of this paper is to determine radioactivity levels in the effluents of hospitals with Nuclear Medicine Departments. The radiological study of hospital discharges was carried out by gamma spectrometry, and liquid scintillation spectrometry to determine (14)C and (3)H contents. On March 9th and April 19th, 2010, daily radioactivity levels were monitored from 8:30 a.m. to 7:30 p.m. Each sample was collected at a specific control point of two major public hospitals in Granada (Spain). The analytical results show the presence of radionuclides such as (99m)Tc, (131)I, (67)Ga, and (111)In.They are frequently used in nuclear medicine for diagnostic and/or therapeutic purposes. This study shows the differences between direct and after-storage discharges and also justifies the need of storage tanks in hospitals with nuclear medicine departments. Moreover, monitoring of (99m)Tc released at hospital control points can be a useful tool for optimizing the safety conditions of storage tanks and discharge of radionuclides.

Traces of fission products in southeast Spain after the Fukushima nuclear accident.

Traces of (131)I, (134)Cs and (137)Cs were measured after the Fukushima nuclear accident between 23 March and 13 April 2011 in southeast Spain. The movement of the radioactive cloud toward southeast Spain was reconstructed based on the backward and forward trajectory cluster analyses. Polar maritime air masses which had originated over North America transported the radioactive plume toward the southeast Spain. Aerosols, rainwater, vegetables and cheese were analyzed to determine the radioactive risk. The highest concentrations of (131)I, (134)Cs and (137)Cs in air samples were 2.63 ± 0.12 mBq/m(3); 0.10 ± 0.03 mBq/m(3); 0.09 ± 0.02 mBq/m(3), respectively. After precipitation on April 3rd, the maximum concentrations of (131)I, (134)Cs and (137)Cs were detected in rainwater samples, 1.10 ± 0.16 mBq/L; 0.022 ± 0.003 mBq/L; 0.05 ± 0.03 mBq/L, respectively. As a consequence, (131)I was transferred to the human food chain, and found in chard and goat cheese, 0.97 ± 0.20 Bq/kg and 0.52 ± 0.08 Bq/kg, respectively. The traces of (131)I, (134)Cs and (137)Cs detected in the different samples were so low, that there is no impact on human health or the environment in Spain after the Fukushima nuclear accident.