title: Effects of source rocks, soil features and climate on natural gamma radioactivity in the Crati valley (Calabria, Southern Italy).
abstract: The study, which represents an innovative scientific strategy to approach the study of natural radioactivity in terms of spatial and temporal variability, was aimed to characterize the background levels of natural radionuclides in soil and rock in the urban and peri-urban soil of a southern Italy area; to quantify their variations due to radionuclide bearing minerals and soil properties, taking into account nature and extent of seasonality influence. Its main novelty is taking into account the effect of climate in controlling natural gamma radioactivity as well as analysing soil radioactivity in terms of soil properties and pedogenetic processes. In different bedrocks and soils, activities of natural radionuclides ((238)U, (232)Th (4) K) and total radioactivity were measured at 181 locations by means of scintillation γ-ray spectrometry. In addition, selected rocks samples were collected and analysed, using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS) and an X-Ray Powder Diffraction (XRPD), to assess the main sources of radionuclides. The natural-gamma background is intimately related to differing petrologic features of crystalline source rocks and to peculiar pedogenetic features and processes. The radioactivity survey was conducted during two different seasons with marked changes in the main climatic characteristics, namely dry summer and moist winter, to evaluate possible effects of seasonal climatic variations and soil properties on radioactivity measurements. Seasonal variations of radionuclides activities show their peak values in summer. The activities of (238)U, (232)Th and (4) K exhibit a positive correlation with the air temperature and are negatively correlated with precipitations.
authors.affiliation: National Research Council of Italy - Institute for Agricultural and Forest Systems in the Mediterranean (ISAFOM), Via Cavour 4/6, 87036, Rende, CS, Italy. Electronic address: ilaria.guagliardi@isafom.cnr.it.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Guagliardi
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Natalia
authors.initials: N
authors.lastname: Rovella
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Apollaro
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bloise
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: De Rosa
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Scarciglia
authors.affiliation: Department of Biology, Ecology and Earth Sciences - DiBEST, University of Calabria, Ponte Bucci, 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Buttafuoco
mesh_terms: D001417:Background Radiation; D002980:Climate; D005720:Gamma Rays; D019015:Geologic Sediments / Q000737:chemistry*; D007558:Italy; D011834:Radiation Monitoring / Q000379:methods*; D011868:Radioisotopes / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma
chemical_list: D011868:Radioisotopes; D012987:Soil; D012990:Soil Pollutants, Radioactive
keywords: Climate; Crystalline rocks; Natural radioactivity; Seasonal control; Soils