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Direction de l’Environnement et de l’Intervention

Towards a protection of species at the population level: derivation of PNEDR values by modelling population responses to ionizing radiations Emilie Lance, Frédéric Alonzo, Jacqueline Garnier-Laplace. EMRAS Meeting, 26-27/01/2010, Vienna, Austria.

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Direction de l’Environnement et de l’Intervention

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  1. Towards a protection of species at the population level: derivation of PNEDR values by modelling population responses to ionizing radiations Emilie Lance, Frédéric Alonzo, Jacqueline Garnier-Laplace EMRAS Meeting, 26-27/01/2010, Vienna, Austria Direction de l’Environnement et de l’Intervention Service d’Etude du Comportement des Radionucléides dans les Ecosystèmes Laboratoire de Modélisation Environnementale

  2. IAEA : standards for environmental radioprotection ICRP : recommendation of similar method than for chemical substances, 2005 Sept Background on ERICA and PROTECT: recommendation Evaluation of environmental risk from ionizing radiations European projects: • FASSET (2001-2004) 5th PCRD • ERICA (2004-2007) 6th PCRD • PROTECT (2006-2008) 6th PCRD Risk assessment screening dose or dose rate, « benchmarks » for the protection of wild species againts impact of ionizing radiations. EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  3. Background on ERICA and PROTECT: data set Biological complexity FREDERICA database : effects of ionizing radiations on non-human organisms • Ecotoxicity data • 25000 couples (dose or dose rate, effect) from 1040 references • 16 pseudo-taxonomic groups • 3 ecosystems EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  4. Background on ERICA and PROTECT: data set Which data for the derivation of benchmarks ? • Effects observed at the individual and sub-individual level 4 categories: - (1) morbidity: growth rate, immune system, behavior (impact on the central nervous system), - (2) mortality: also mutations that affect life expectancy - (3) reproductive capacity: fertility, fecundity, hatching/survival of embryos… - (4) mutations of somatic and reproductive cells On the first hand, data on chronic exposure to gamma radiation, external radiation exposure (µGy.h-1) EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  5. Background on ERICA and PROTECT: method Effect (%) Regression model Experimental data 10 ED50 EDR50 ED10 EDR10 Dose (Gy) Dose rate (µGy/h) Derivation of criteria for the protection of populations Radiotoxicity data relative to life-history traits (protection of the population) Dose (rate)-effectrelationships: critical data, EDR10 (dose rate inducing 10% of effect on the endpoint in comparison with controls) For a given species, if an EDR10 is available for several endpoints, the most sensitive is selected EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  6. Background on ERICA and PROTECT:method 5% HDR5 Derivation of criteria for the protection of populations Extrapolation model « Species Sensitivity Distribution » (SSD) HDR5 = Dose rate protecting 95% of species (95% are affected at maximum 10% of effect in comparison with controls) Garnier-Laplace et al. (2008) HDR5 / safety factor = PNEDR (Predicted No Effect Dose Rate) EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  7. Background on ERICA and PROTECT:possible improvements dynamics Hypothesis: the toxicity at the individual level is comparable between species and endpoints Sensitivity of the population growth rate to impact on individuals endpoints Ecosystem level Community level Population level Ecotoxicity data at the individual level Whole organism level Life history strategies Physiological level Life-history traits: survival, growth, fecundity impact Biochemical level Time scale EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  8. Background on ERICA and PROTECT:possible improvements Abundance S i Survival rate Pi depending on age i Fecundity rate Fi Ni at time t N1= Fi Ni Ni+1=Pi Ni at timet + 1 1 2 3… time i age age max Eggs, juveniles (future cohort N1) Population dynamic depending on survival and reproduction in each life stage 1)Population structured per age classes 2) Cohorts vary over time depending on survival and fecundity  Modeling population size in number  Determination of population growth rate EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  9. Background on ERICA and PROTECT:possible improvements Daphnia magna toxicité chronique de U et Am-241 dissous et radiations gamma externes (Cs-137) Eisenia fetida • toxicité chronique • de radiations gamma • externes (Co-60) Reduction in survival Reduction in fecundity Delay in reproduction 3.0 3.0 2.0 2.0 1.0 1.0 0.0 0.0 0% 0% 20% 20% 40% 40% 60% 60% 80% 80% Comparison of population sensitivity to changes in different endpoints and different species Alonzo et al., 2008 Delay in population growth (relative to generation time T) T = 12 weeks T = 10 days Individual level effect  Sensitivity of population depends on individual endpoints • Sensitivity of population depends onlife history strategy of different species EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  10. Toward a protection of species at the population level Hypothesis of the model 100000 Enclosed system 75000 No density-dependence Effect (%) Optimum environnemental conditions 50000 Relative sensitivity of the population to different individual endpoints for a species To understand and compare life-history strategies between different species Bibliography 25000 • age sexual maturity • survival at each stage • fecundity at each stage • (number of eggs, hatching %, • juveniles survival…) 0 10 0 15 30 45 60 Population dynamic ED10 EDR10 Dose rate (µGy/h) taille de population time (days) Method and required data: a first theoretical step 2nd step: utilization of data from FREDERICA Simulation of population dynamics of each species in control conditions and with 0 to 100% decrease in each life-history trait % Dose rate ? • 10% on the population growth rate modélisation Pop-EDR10: Dose rate inducing 10% decrease in population growth rate EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  11. Toward a protection of species at the population level 5% HDR5 Derivationof benchmarks Extrapolation model « Species Sensitivity Distribution » (SSD) with pop-EDR10 = at the population level New HDR5 = Dose rate protecting population dynamics for 95% of species (decrease in population growth rate of less than 10% in comparison with controls) Pop-EDR10 EMRAS Meeting, 2010-01-26/27, Vienna, Austria

  12. Thanks for your attention // more informations on… European program ERICA Risques des substances radioactives pour l’environnement http://www.erica-project.org European program PROTECT Protection of the environment from ionising radiation in a regulatory context http://www.ceh.ac.uk/protect/ FREDERICA Radiation Effects Database http://87.84.223.229/fred/mainpage.asp http://www.irsn.org/ CIPR http://www.icrp.org NEA http://www.nea.fr EMRAS Meeting, 2010-01-26/27, Vienna, Austria

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