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 Direction de l’Environnement et de l’Intervention Service d’Etude du Comportement des Radionucléides dans les Ecosystèmes Laboratoire de Modélisation Environnementale EMRAS Meeting, 26-27/01/2010, Vienna, Austria

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

- Titre Partie/Dir/Service – Page 3 FREDERICA database : effects of ionizing radiations on non-human organisms Ecotoxicity data couples (dose or dose rate, effect) from 1040 references 16 pseudo-taxonomic groups 3 ecosystems Ecosystems terrestrial freshwater marine Biological complexity Background on ERICA and PROTECT: data set EMRAS Meeting, /27, Vienna, Austria

- Titre Partie/Dir/Service – Page 4 Effects observed at the individual and sub-individual level Which data for the derivation of benchmarks ? On the first hand, data on chronic exposure to gamma radiation, external radiation exposure (µGy.h -1 ) 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 Background on ERICA and PROTECT: data set EMRAS Meeting, /27, Vienna, Austria

- Titre Partie/Dir/Service – Page 5 Radiotoxicity data relative to life-history traits (protection of the population) Dose (rate)-effect relationships: 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 Derivation of criteria for the protection of populations Effect (%) Dose (Gy) Dose rate (µGy/h) ED10 EDR10 ED50 EDR50 10 Regression model Experimental data Background on ERICA and PROTECT: method EMRAS Meeting, /27, Vienna, Austria

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

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

- Titre Partie/Dir/Service – Page 8 age Abundance time 1) Population structured per age classes 2) Cohorts vary over time depending on survival and fecundity 1 2 3… i age max N i+1 = P i  N i at time t + 1 i  N 1 = F i  N i N i at time t Eggs, juveniles (future cohort N 1 )  Modeling population size in number  Determination of population growth rate Population dynamic depending on survival and reproduction in each life stage Fecundity rate F i Survival rate P i depending on age i Background on ERICA and PROTECT: possible improvements EMRAS Meeting, /27, Vienna, Austria

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

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

- Titre Partie/Dir/Service – Page 11 5% HDR 5 Derivation of benchmarks Extrapolation model « Species Sensitivity Distribution » (SSD) with pop-EDR10 = at the population level New HDR 5 = Dose rate protecting population dynamics for 95% of species (decrease in population growth rate of less than 10% in comparison with controls) Pop-EDR 10 Toward a protection of species at the population level EMRAS Meeting, /27, Vienna, Austria

- Titre Partie/Dir/Service – Page 12 Thanks for your attention // more informations on… European program ERICA Risques des substances radioactives pour l’environnement European program PROTECT Protection of the environment from ionising radiation in a regulatory context FREDERICA Radiation Effects Database CIPR NEA EMRAS Meeting, /27, Vienna, Austria