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Lecomte-Pradines C.,Institute for Radiological Protection and Nuclear Safety | Bonzom J.-M.,Institute for Radiological Protection and Nuclear Safety | Della-Vedova C.,Magelis | Beaugelin-Seiller K.,Institute for Radiological Protection and Nuclear Safety | And 7 more authors.
Science of the Total Environment | Year: 2014

In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22μGyh-1. These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H'). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200μGyh-1. This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites. This might result from a selection at the expense of sensitive species after the accident. © 2013 Elsevier B.V.

Buisset-Goussen A.,Institute for Radiological Protection and Nuclear Safety | Goussen B.,Institute for Radiological Protection and Nuclear Safety | Goussen B.,INERIS | Della-Vedova C.,Magelis | And 3 more authors.
Journal of Environmental Radioactivity | Year: 2014

The effects of chronic exposure to 137Cs gamma radiation (dose rate ranging from 6.6 to 42.7mGyh-1) on growth and reproductive ability were carried out over three generations of Caenorhabditis elegans (F0, F1, and F2). Exposure began at the egg stage for the first generation and was stopped at the end of laying of third-generation eggs (F2). At the same time, the two subsequent generations from parental exposure were returned to the control conditions (F1' and F2'). There was no radiation-induced significant effect on growth, hatchability, and cumulative number of larvae within generations. Moreover, no significant differences were found in growth parameters (hatching length, maximal length, and a constant related to growth rate) among the generations. However, a decrease in the cumulative number of larvae across exposed generations was observed between F0 and F2 at the highest dose rate (238.8±15.4 and 171.2±13.1 number of larvae per individual, respectively). Besides, the F1' generation was found to lay significantly fewer eggs than the F1 generation for tested dose rates 6.6, 8.1, 19.4, and 28.1mGyh-1. Our results confirmed that reproduction (here, cumulative number of larvae) is the most sensitive endpoint affected by chronic exposure to ionizing radiation. The results obtained revealed transgenerational effects from parental exposure in the second generation, and the second non-exposed generation was indeed more affected than the second exposed generation. © 2014 Elsevier Ltd.

Adam-Guillermin C.,Institute for Radiological Protection and Nuclear Safety | Pereira S.,Institute for Radiological Protection and Nuclear Safety | Della-Vedova C.,Magelis | Hinton T.,Institute for Radiological Protection and Nuclear Safety | Garnier-Laplace J.,Institute for Radiological Protection and Nuclear Safety
Reviews of Environmental Contamination and Toxicology | Year: 2012

Aquatic systems are inhabited by a large variety of species, several of which comprise important components in human diets. Aquatic systems are also the final receptors of a whole range of pollutants, including radioactive ones, because the majority of nuclear facilities are connected to either rivers or to the marine environment. © 2012 Springer Science+Business Media, LLC.

Garnier-Laplace J.,CEA Cadarache Center | Della-Vedova C.,Magelis | Andersson P.,Swedish Radiation Safety Authority | Copplestone D.,UK Environment Agency | And 6 more authors.
Journal of Radiological Protection | Year: 2010

Dose rate benchmarks are required in the tiered approaches used to screen out benign exposure scenarios in radiological ecological risk assessment. Such screening benchmarks, namely the predicted no-effect dose rates (PNEDR), have been derived by applying, as far as possible, the European guidance developed for chemicals. To derive the ecosystem level (or generic) PNEDR, radiotoxicity EDR10 data (dose rates giving a 10% effect in comparison with the control) were used to fit a species sensitivity distribution (SSD) and estimate the HDR5 (the hazardous dose rate affecting 5% of species with a 10% effect). Then, a multi-criteria approach was developed to justify using an assessment factor (AF) to apply to the HDR5 for estimating a PNEDR value. Several different statistical data treatments were considered which all gave reasonably similar results. The suggested generic screening value of 10 μGyh-1 (incremental dose rate) was derived using the lowest available EDR10 value per species, an unweighted SSD, and an AF of 2 applied to the estimated HDR5. Consideration was also given to deriving screening benchmark values for organism groups but this was not thought to be currently appropriate due to few relevant data being currently available. © 2010 IOP Publishing Ltd.

Garnier-Laplace J.,Institute for Radiological Protection and Nuclear Safety | Geras'kin S.,All Russian Research Institute of Agricultural Meteorology | Della-Vedova C.,Magelis | Beaugelin-Seiller K.,Institute for Radiological Protection and Nuclear Safety | And 3 more authors.
Journal of Environmental Radioactivity | Year: 2013

The discrepancy between laboratory or controlled conditions ecotoxicity tests and field data on wildlife chronically exposed to ionising radiation is presented for the first time. We reviewed the available chronic radiotoxicity data acquired in contaminated fields and used a statistical methodology to support the comparison with knowledge on inter-species variation of sensitivity to controlled external γ irradiation. We focus on the Chernobyl Exclusion Zone and effects data on terrestrial wildlife reported in the literature corresponding to chronic dose rate exposure situations (from background∼100 nGy/h up to ∼10 mGy/h). When needed, we reconstructed the dose rate to organisms and obtained consistent unbiased data sets necessary to establish the dose rate-effect relationship for a number of different species and endpoints. Then, we compared the range of variation of radiosensitivity of species from the Chernobyl-Exclusion Zone with the statistical distribution established for terrestrial species chronically exposed to purely gamma external irradiation (or chronic Species radioSensitivity Distribution - SSD). We found that the best estimate of the median value (HDR50) of the distribution established for field conditions at Chernobyl (about 100 μGy/h) was eight times lower than the one from controlled experiments (about 850 μGy/h), suggesting that organisms in their natural environmental were more sensitive to radiation. This first comparison highlights the lack of mechanistic understanding and the potential confusion coming from sampling strategies in the field. To confirm the apparent higher sensitive of wildlife in the Chernobyl Exclusion Zone, we call for more a robust strategy in field, with adequate design to deal with confounding factors. © 2012 Elsevier Ltd.

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