title: Contribution for the derivation of a soil screening value (SSV) for uranium, using a natural reference soil.
abstract: In order to regulate the management of contaminated land, many countries have been deriving soil screening values (SSV). However, the ecotoxicological data available for uranium is still insufficient and incapable to generate SSVs for European soils. In this sense, and so as to make up for this shortcoming, a battery of ecotoxicological assays focusing on soil functions and organisms, and a wide range of endpoints was carried out, using a natural soil artificially spiked with uranium. In terrestrial ecotoxicology, it is widely recognized that soils have different properties that can influence the bioavailability and the toxicity of chemicals. In this context, SSVs derived for artificial soils or for other types of natural soils, may lead to unfeasible environmental risk assessment. Hence, the use of natural regional representative soils is of great importance in the derivation of SSVs. A Portuguese natural reference soil PTRS1, from a granitic region, was thereby applied as test substrate. This study allowed the determination of NOEC, LOEC, EC20 and EC50 values for uranium. Dehydrogenase and urease enzymes displayed the lowest values (34.9 and <134.5 mg U Kg, respectively). Eisenia andrei and Enchytraeus crypticus revealed to be more sensitive to uranium than Folsomia candida. EC50 values of 631.00, 518.65 and 851.64 mg U Kg were recorded for the three species, respectively. Concerning plants, only Lactuca sativa was affected by U at concentrations up to 1000 mg U kg(1). The outcomes of the study may in part be constrained by physical and chemical characteristics of soils, hence contributing to the discrepancy between the toxicity data generated in this study and that available in the literature. Following the assessment factor method, a predicted no effect concentration (PNEC) value of 15.5 mg kg-1dw was obtained for U. This PNEC value is proposed as a SSV for soils similar to the PTRS1.
authors.affiliation: Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal; CESAM, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
authors.forename: Ana Luisa
authors.initials: AL
authors.lastname: Caetano
authors.affiliation: Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal; CESAM, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
authors.forename: Catarina R
authors.initials: CR
authors.lastname: Marques
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal; CESAM, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Gavina
authors.affiliation: Nuclear and Technological Institute (ITN) Department of Radiological Protection and Nuclear Safety, Sacavém, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Carvalho
authors.affiliation: Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal; CESAM, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gonçalves
authors.affiliation: Department of Geosciences, University of Aveiro, GeoBioTec Research Center, Campus Universitário de Santiago, Aveiro, Portugal.
authors.forename: Eduardo Ferreira
authors.initials: EF
authors.lastname: da Silva
authors.affiliation: Department of Biology, Faculty of Sciences of the University of Porto, Porto, Portugal; Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal.
authors.forename: Ruth
authors.initials: R
authors.lastname: Pereira
mesh_terms: D000818:Animals; D054750:Ecotoxicology; D007448:Invertebrates / Q000187:drug effects*; D010944:Plants / Q000187:drug effects*; D018570:Risk Assessment; D012988:Soil Microbiology; D012990:Soil Pollutants, Radioactive / Q000633:toxicity*; D014501:Uranium / Q000633:toxicity*
chemical_list: D012990:Soil Pollutants, Radioactive; D014501:Uranium