Potential Source Apportionment and Meteorological Conditions Involved in Airborne 131I Detections in January/February 2017 in Europe.

Traces of particulate radioactive iodine (131I) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 µBq m-3 except at one location in western Russia where they reached up to several mBq m-3. Detections have been reported continuously over an 8-week period by about 30 monitoring stations. We examine possible emission source apportionments and rank them considering their expected contribution in terms of orders of magnitude from typical routine releases: radiopharmaceutical production units > sewage sludge incinerators > nuclear power plants > spontaneous fission of uranium in soil. Inverse modeling simulations indicate that the widespread detections of 131I resulted from the combination of multiple source releases. Among them, those from radiopharmaceutical production units remain the most likely. One of them is located in Western Russia and its estimated source term complies with authorized limits. Other existing sources related to 131I use (medical purposes or sewage sludge incineration) can explain detections on a rather local scale. As an enhancing factor, the prevailing wintertime meteorological situations marked by strong temperature inversions led to poor dispersion conditions that resulted in higher concentrations exceeding usual detection limits in use within the informal Ring of Five (Ro5) monitoring network.

Study on transfers of uranium, thorium and decay products from grain, water and soil to chicken meat and egg contents.

Activity concentrations of the uranium and thorium series radionuclides were determined in chicken meat and eggs as well as in soil, water and other dietary intakes of poultry at five sites of the French territory. These data allow the calculation of transfer coefficients which enrich the database given by the technical report series no. 472 of the IAEA. In egg contents, the highest activity concentrations (in mBq kg(-1) fresh weight) are for (226)Ra, ranging between 136 and 190 and are much lower for uranium (between 0.51 and 1.30 for (238)U). In chicken meat, (238)U activity concentration is higher than in egg contents and ranges between 1.7 and 9.7. Concerning (232)Th, its activity concentration is lower than uranium and ranges between 0.5 and 4.9. Daily ingested activity concentration by the animals was assessed taking into account the activity concentrations measured in the grains, in the soil and in the drinking water. The activity concentration in grains and the daily intakes allow the calculation of concentration ratios and transfer coefficients for chicken meat and egg contents. In chicken meat the transfer coefficients (d kg(-1)) range between 0.0018 and 0.0073 for (238)U and between 0.0008 and 0.0028 for (232)Th. In egg contents they range from 0.00018 to 0.0018 for (238)U and are much higher for radium isotopes (0.10-0.23 for (226)Ra and 0.07-0.11 for (228)Ra).

Potential sources affecting the activity concentrations of 238U, 235U, 232Th and some decay products in lettuce and wheat samples.

The activity concentrations of radionuclides within the uranium and thorium series were determined in wheat and lettuce at five sites in France, and in their respective potential sources: crop soils of wheat and crop soils and irrigation waters of lettuce. These data were used to calculate concentration ratios and to enrich the database supported by the technical report series N°472 of the IAEA (2010). For wheat and lettuce, the activity concentrations were in the same range for all radionuclides studied, except for (210)Pb, which had higher activity concentrations in wheat, ranging between 1.3 and 11 Bq kg(−1) (fresh weight) as compared to 0.4 and 0.7 Bq kg(−1) (fresh weight) for lettuce. For wheat, the range of activity concentrations (mBq kg(−1); fresh weight) decreased as (210)Pb > (226)Ra (56­1511) ≈ (228)Ra (86­769) > (228)Th (19­176) ≈ (238)U (11­169) ≈ (234)U (12­150) ≈ (230)Th (9.08­197.18) ≈ (232)Th (8.61­121.45) > (235)U (0.53­7.9). For lettuce, it decreased as (228)Ra (<320­1221) > (210)Pb (409­746) > (226)Ra (30­599) ≈ (228)Th (<29­347) > (238)U (8­120) ≈ (234)U (8­121) ≈ (230)Th (5.21­134.63) ≈ (232)Th (5.25­156.99) > (235)U (0.35­5.63). The species differences may reflect different plant physiologies. Through the study of activity ratios of wheat and lettuce in relation with those of the various radionuclide sources it has been possible to highlight the contribution of the main sources of natural radionuclides. Indeed, irrigation water when the uranium concentration is enhanced (>30 mBq L(−1)) contributed significantly to the activity concentration of uranium in lettuces. Concerning the high activity concentrations of (210)Pb, it could be explained by atmospheric particle deposition. The effect of soil particles resuspension and their adhesion to the plant surface seemed to be important in some cases. The soil-to-plant transfer factors were calculated for lettuce and wheat. The values were lower in wheat than in lettuce except for (210)Pb which had similar values in the two species (0.11­0.13 respectively). For both species, (210)Pb followed by (228)Ra (0.015­0.10) and (226)Ra (0.010­0.051) displayed the highest transfer factor, whereas (238)U had intermediate values (0.0015­0.030) and (232)Th exhibited the lowest (0.0014­0.013).

Transfer of 131I from Fukushima to the vegetation and milk in France.

Iodine-131 and various other radionuclides were released into the atmosphere from the damaged Japanese reactors of Fukushima Dai-ichi from 12 to 22 March 2011. The contaminated air mass was detected in France after 24 March; samples of grass, vegetables, and milk have been analyzed for (131)I by the IRSN, considering the fact that few values of iodine-131 transfer parameters have been directly measured in situ, due to the radioactive decay of this isotope. Data are compared with calculated values according to the air iodine concentration. The apparent dry deposition velocity of iodine on grass is therefore estimated to range between 1 × 10(-3) and 5 × 10(-3) m s(-1) from site to site. In addition, the grass to milk transfer factors are 2.8 × 10(-2) and 3.6 × 10(-3) d L(-1) for goat's and cow's milk respectively. These parameters fit well with the current values usually considered for radioecological assessment.

Isotopic evidence of natural uranium and spent fuel uranium releases into the environment.

Uranium and plutonium isotopes were measured in soils, sediments and waters in an area subject to the past and present discharges from the uranium conversion plant of Malvési (France). The isotopes (236)U and (239)Pu are well known activation products of uranium and they prove to be powerful tracers of spent fuel releases in soils and sediments. On the other hand (234)U and (238)U activities measured in waters can be used to distinguish between releases and background uranium sources. Such findings contribute to improve the monitoring of the actinides releases by nuclear fuel facilities (mining sites, conversion, enrichment and fuel plants, reprocessing plants).

Actinides and decay products in selected produce and bioindicators in the vicinity of a uranium plant.

Cypress needles collected at the edge of the Malvési uranium facility (SW France) exhibit enhanced activities of actinides and some decay products (uranium, americium, plutonium, (230)Th, (226)Ra) compared to a remote site. These enhanced activities resulted from the release of U via smokestacks and passive release from former artificial ponds located inside the nuclear site. Enhanced activities are also observed in selected produce (wheat, lettuce, fruits) sampled from the edge of the site. However, excess actinides measured in wheat grains in 2007 are inconsistent with the activities and the uranium ratio measured in the soils. This result suggests that the studied annual crops were contaminated mainly through the short-term release of airborne actinides, and that other transfer pathways, such as, uptake through the roots or adhesion of soil particles, were negligible.

Variations in the transfer of radiocesium (137Cs) and radiostrontium (90Sr) from milk to cheese.

This study aimed to compare the transfer of 2 manmade radionuclides, radiocesium (137Cs) and radiostrontium (90Sr), from cow milk to whey and cheese in 3 different types of French cheese production with rennet coagulation. Most of the 137Cs was present in the aqueous phase and became concentrated in the whey. For 137Cs transfer to whey, the processing factor (Pf; i.e., the ratio of the activity concentrations) ranged between 0.86 and 1.30 (n = 12). The food processing retention factor (Fr), calculated using the processing efficiency, ranged between 0.85 and 1.19 (n = 9). No statistical difference of Pf and Fr to whey is identified for 137Cs and the cheese products. The Pf calculated for 90Sr transfer to cheese ranged between 3.95 and 12.16, with significant differences depending on the type of cheese. In addition, a linear correlation is observed between 90Sr Pf to cheese and the Ca level in the cheese (r2 = 0.57). Thus, the Pf is enhanced in hard cheeses that are enriched in calcium. This is confirmed by nearly constant Fr values, ranging between 0.66 and 0.83.

Radioisotope contaminations from releases of the Tomsk-Seversk nuclear facility (Siberia, Russia).

Soils have been sampled in the vicinity of the Tomsk-Seversk facility (Siberia, Russia) that allows us to measure radioactive contaminations due to atmospheric and aquatic releases. Indeed soils exhibit large inventories of man-made fission products including 137Cs (ranging from 33,000 to 68,500 Bq m(-2)) and actinides such as plutonium (i.e. 239+240Pu from 420 to 5900 Bq m(-2)) or 241Am (160-1220 Bq m(-2)). Among all sampling sites, the bank of the Romashka channel exhibits the highest radioisotope concentrations. At this site, some short half-life gamma emitters were detected as well indicating recent aquatic discharge in the channel. In comparison, soils that underwent atmospheric depositions like peat and forest soils exhibit lower activities of actinides and 137Cs. Soil activities are too high to be related solely to global fallout and thus the source of plutonium must be discharges from the Siberian Chemical Combine (SCC) plant. This is confirmed by plutonium isotopic ratios measured by ICP-MS; the low 241Pu/239Pu and 240Pu/239Pu atomic ratios with respect to global fallout ratio or civil nuclear fuel are consistent with weapons grade signatures. Up to now, the influence of Tomsk-Seversk plutonium discharges was speculated in the Ob River and its estuary. Isotopic data from the present study show that plutonium measured in SCC probably constitutes a significant source of plutonium in the aquatic environment, together with plutonium from global fallout and other contaminated sites including Tomsk, Mayak (Russia) and Semipalatinsk (Republic of Kazakhstan). It is estimated that the proportion of plutonium from SCC source can reach 45% for 239Pu and 60% for 241Pu in the sediments.

The Actifetus system: a multidoppler sensor system for monitoring fetal movements.

Fetal heart rate (FHR) monitoring is a crucial part of monitoring at-risk pregnancies and labor. Its aim is to detect any abnormalities that might indicate acute fetal distress and a need for rapid treatment to avoid death or serious sequelae, including cerebral handicap. The use of fetal biophysical profiles in high-risk pregnancies (gravidic hypertension, in utero infection, etc.) helps to distinguish healthy fetuses from those with chronic conditions. Fetal biophysical profile scores have been developed that integrate five biophysical parameters, one of which is derived from the FHR. The major parameters detected are the rate of fetal movements, fetal tone, fetal breathing movement and amniotic fluid volume. All of those parameters except FHR are obtained by prolonged echographic observation and cannot be used routinely. We developed in this study a new multigate multitransducer pulsed Doppler system for survey of fetal behavior. Fast Fourier transform and autocorrelation function have been used for processing and analyzing ultrasonic Doppler signals generated by fetal movements. Several parameters are analyzed in each of the 12 x 5 = 60 Doppler gates: amplitude of signals reflected by moving fetal structures, velocity, direction and amplitude of displacement of fetal structure (heart, chest, limbs). From these parameters it is possible to calculate FHR and characterize fetal activity. Preliminary in vivo results obtained in 15 pregnant women (30 to 36 wk) are very encouraging but they have yet to be confirmed in future studies. These results also demonstrate the advantages of transducers designed for improved fetal movement detection. The algorithms needs to be precise enough to allow the Actifetus system to function in real time. We now have at our disposal some algorithms that succeed in quantifying FHR and fetal movements with a signal from a given sensor at a given depth. This study confirms the feasibility of monitoring fetal movements by the Actifetus system and demonstrates the importance of the characterization of fetal rhythms (and fetal behavior). The Actifetus system will serve as a new mean for studying fetal response to environment and detecting anomalies related to fetal suffering.

Lower variability of radionuclide activities in upland dairy products compared to soils and vegetation: implication for environmental survey.

Contamination of the environment by radionuclides is usually estimated using soil and grass sampling. However, radionuclides are often not homogeneously distributed in soils. In the alpine Mercantour region (Western Alps, France) a large heterogeneity in Chernobyl 137Cs deposition has been previously observed. Here we report additional 137Cs results together with new 90Sr and Pu data for soil, grass, milk, and cheese samples. The results show that radioisotopes from nuclear weapons tests fallout are more homogeneously distributed than Chernobyl 137Cs. Further, we observe that the 137Cs and 90Sr contents are less variable in milk samples than in grass or soil samples. This can be attributed to the homogenization effect of cow vagrancy during grazing. Hence milk seems to be a more robust sample than soil or grass to evaluate the extent of contamination on a regional scale. We explore this idea by comparing own unpublished 90Sr results and 90Sr results from the literature to establish the relationship between altitude of grazing and contamination of soil and milk for Western Europe. There is a significant positive correlation between soil contamination and altitude and an even closer correlation between milk 90Sr activity (A) and altitude (h): A = A0 + e(k x h) where A0 is the expected activity of milk sampled at sea level (A0 = 0.064 +/- 0.014 Bq g(-1) Ca) and h is the altitude of grazing, k being a constant (k = 0.95 x 10(-3) +/- 0.11 x 10(-3) m(-1) Bq g(-1) Ca). The fact that there is less scattering in the relationship for the 90Sr(milk)-altitude than for 90Sr(soil)-altitude suggests, again, that milk is a well-suited sample for environmental survey. The relationship between the altitude of grazing and the 90Sr content of milk and cheese can also be used to assess the authenticity of dairy products.

Mechanisms of enrichment of natural radioactivity along the beaches of the Camargue, France.

A field study was carried out along the Golfe du Lion, that focussed on the beaches of the Camargue, to locate the main areas where enriched U and Th are found, and to better understand the processes that concentrate radioactivity on beaches. Indeed enriched areas are observed on some Camargue beaches, where high-dose rates are recorded due to excess U and Th activity (>1000 Bq kg(-1)). The coastline was mapped by means of an aerial gamma survey and the results indicated that the main actinides deposits occurred in the Camargue area. This concentrating effect is possibly due to a greater sedimentary contribution from the River Rhone relative to other minor Mediterranean rivers. Across the along-shore profile, the variability in actinides observed at the eastern part of Beauduc spit is mainly explained by variations in heavy and light mineral contents. Such variability can be accounted for by redistribution of the sand caused by erosion/deposition processes occurring in the eastern part of the spit. Further parameters such as grain size and heavy minerals content were studied in connection with the distribution of U, Th and (40)K in the field at a more localised level (i.e. across-shore beach profile). The <200-micro m fraction contains more than 50% of the radioactivity and heavy minerals (especially zircon) are the main contributors to the high levels of external radiation. Therefore the enriched areas, where U and Th exceed 1000 Bq kg(-1), presumably result from the sorting of sand grains according to their size and density.

Trace elements and Pb isotopes in soils and sediments impacted by uranium mining.

The purpose of this study is to evaluate the contamination in As, Ba, Co, Cu, Mn, Ni, Sr, V, Zn and REE, in a high uranium activity (up to 21,000Bq∙kg(-1)) area, downstream of a former uranium mine. Different geochemical proxies like enrichment factor and fractions from a sequential extraction procedure are used to evaluate the level of contamination, the mobility and the availability of the potential contaminants. Pb isotope ratios are determined in the total samples and in the sequential leachates to identify the sources of the contaminants and to determine the mobility of radiogenic Pb in the context of uranium mining. In spite of the large uranium contamination measured in the soils and the sediments (EF≫40), trace element contamination is low to moderate (2

Environmental consequences of uranium atmospheric releases from fuel cycle facility: II. The atmospheric deposition of uranium and thorium on plants.

Uranium and thorium isotopes were measured in cypress leaves, wheat grains and lettuce taken in the surroundings of the uranium conversion facility of Malvési (South of France). The comparison of activity levels and activity ratios (namely (238)U/(232)Th and (230)Th/(232)Th) in plants with those in aerosols taken at this site and plants taken far from it shows that aerosols emitted by the nuclear site (uranium releases in the atmosphere by stacks and (230)Th-rich particles emitted from artificial ponds collecting radioactive waste mud) accounts for the high activities recorded in the plant samples close to the site. The atmospheric deposition process onto the plants appears to be the dominant process in plant contamination. Dry deposition velocities of airborne uranium and thorium were measured as 4.6 × 10(-3) and 5.0 × 10(-3) m s(-1), respectively.

Uranium decay daughters from isolated mines: Accumulation and sources.

This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO4). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals.

Blood flow response to auditory stimulations in normal, mentally retarded, and autistic children: a preliminary transcranial Doppler ultrasonographic study of the middle cerebral arteries.

Using the noninvasive transcranial ultrasonic Doppler method, flow dynamics of the middle cerebral arteries were investigated in relation to auditory stimulations in 12 children with autistic behavior compared with 12 normal controls and 10 mentally retarded children. In normal children, auditory stimulation evoked lateralized modifications: blood flow increased and resistance index decreased on the left side; such modifications were not recorded on the right side. This pattern should indicate vasodilatation mechanisms induced by changes in the metabolism of the brain areas supplied by the left middle cerebral arteries (MCA). Although less asymmetrical, this pattern was also found in the mentally retarded children. Autistic children significantly differed from these two groups. They displayed a symmetric pattern of responses with a blood flow decrease and resistance-index increase on both sides; this could suggest abnormal metabolic mechanisms induced by auditory stimulation in autistic children and could be related to the previous hypothesis of impairment in the development of cerebral lateralization in autism. These preliminary results show that transcranial Doppler ultrasonography may be a valuable and practicable tool for the noninvasive study of evoked blood flow responses in psychopathology.

Therapeutic effectiveness of iodine-131 MIBG metastases of a nonsecreting paraganglioma.

This case report describes the treatment of the bone metastases of a nonfunctioning sympathetic paraganglioma, with [131I]MIBG. After primary tumor excision and unsuccessful external radiotherapy, the patient received three therapeutic doses of [131I]MIBG, resulting in a reduction of the number and volume of metastases, and an improvement of the general condition. At 3 yr following [131I]MIBG therapy, the patient remained in remission. [131I]MIBG appears to be an efficient and safe agent for treating malignant sympathetic paraganglioma.

Ultrasonically guided aspiration biopsy in osteolytic bone lesions of the chest wall.

Sixteen consecutive patients with one or more osteolytic bone lesions of the chest wall radiologically confirmed underwent ultrasonically guided aspiration biopsy. Nine patients (56.2 percent) had bronchogenic carcinoma with a direct extension. Other diagnostic techniques had failed to diagnose disease in these patients. The lesion showed heterogeneous echogenicity (n = 16) caused by the hyperechoic signals of bone fragments. The interruption of the cortex bone was detected in all cases and extraosseous tumor portion in 14 of 16 patients (87.5 percent). No respiratory motions of the lesion could be demonstrated (n = 16). Definitive histologic diagnosis was made in 14 of the 16 patients (87.5 percent). In malignancy, diagnosis was established in 13 of 14 patients (92.8 percent). Of two confirmed benign lesions, one diagnosis of tuberculosis was obtained. No complication occurred. Sonography and consequently ultrasonically guided aspiration biopsy are a useful, accurate, safe, and low-cost technique for osteolytic lesions in thoracic diseases.

Effects of neonatal focal cerebral hypoxia-ischemia on sleep-waking pattern, ECoG power spectra and locomotor activity in the adult rat.

The aim of this study was to determine the influence of neonatal focal cerebral hypoxia-ischemia (HI) on sleep-waking pattern, electrocorticogram (ECoG) power spectra and locomotor activity (LA) in adult Wistar rats. Seven-day old pups were subjected to permanent unilateral ligation of the common carotid artery and transient hypoxia (8% O2). At 10 weeks of age, the extent of brain damages was evaluated by magnetic resonance imaging (MRI) and homogenous injured animals were selected before chronic implantation of radiotelemetry device. Using a single ECoG recording channel method, waking (W), paradoxical sleep (PS) and slow wave sleep (SWS) were continuously recorded for 72 h and they were semi-automatically analyzed off-line. We observed that neonatal HI triggers a cascade of events leading, in adult rats, to brain dysfunction characterized by an increase in SWS (55.0 vs. 40.2% in sham-operated rats, p<0.05) and a marked decrease in W phases duration (43.4 vs. 51.5%, p<0.05) while PS was almost suppressed in HI rats (1.6 vs. 8.3%, p<0.05). In addition, power spectral analysis of ECoG revealed significant (p<0.05) alteration in PS power density with a shift of the dominant frequency peak (5.0 to 7.5 Hz for HI and sham-operated rats, respectively). During the light period, we found that HI induced a pronounced reduction of LA (-30%, p<0.05). These results indicate that Wistar rats exposed to a neonatal unilateral cerebral HI present significant ECoG activity, sleep-waking pattern and behavioral disturbances when adults. However, it remains to establish whether such alterations can be prevented by neuroprotective agents.

Influence of neonatal focal cerebral hypoxia-ischemia on cardiovascular and neurobehavioral functions in adult Wistar rats.

No experimental studies looked at the disturbances appearing after a neonatal focal cerebral hypoxia-ischemia (HI) when animals become adults. Using radiotelemetry, we examined the effects of neonatal focal cerebral HI on blood pressure (BP), heart rate (HR), locomotor activity (LA), body temperature (BT) levels and circadian rhythm parameters of unrestrained adult Wistar rats. At 15 weeks of age, we continuously recorded the cardiovascular and neurobehavioral parameters of HI (n = 6) and sham-operated (n = 6) rats. In adult rats, HI induced persistent hypertensive effects associated with alteration in BP circadian rhythms and pronounced decreases in mesor and percent rhythm of LA. HR and BT parameters were not significantly modified. Therefore, our results suggest that the rat cardiovascular and behavioural circadian control systems may involve several structures which present selective vulnerability to early cerebral HI.

Exploration of the dopamine transporter: in vitro and in vivo characterization of a high-affinity and high-specificity iodinated tropane derivative (E)-N-(3-iodoprop-2-enyl)-2beta-carbomethoxy-3beta-(4'-m ethylph enyl)nortropane (PE2I).

For the diagnosis and follow-up of neurodegenerative diseases, many cocaine derivatives have been proposed as radioligands to explore the dopamine transporter. As none of them have all the criteria of specificity and kinetics for human use, we have developed a new derivative, (E)-N-(3-iodoprop-2-enyl)-2beta-carbomethoxy-3beta-(4'-methy lphenyl)nortropane (PE2I), which displays promising properties. We report the characterization of PE2I in vitro on rat striatal membranes and in vivo in rats and in monkeys. PE2I had a high affinity (Kd = 0.09 +/- 0.01 nM) and high specificity for the dopamine transporter. In rats we observed a high accumulation in the striatum; by contrast, a very low fixation was measured in the cortex. Moreover, a preinjection of a saturating dose of GBR 12909 prevented the striatal accumulation of PE2I by 74%. These results confirmed the specificity of PE2I for the dopamine transporter. In vivo in monkeys, SPECT studies showed a high accumulation in striatum. Moreover, an equilibrium state was obtained 1 h after injection. PE2I seemed to be the most promising ligand for the dopamine transporter exploration by SPECT using a single-day protocol.