Contents lists available at ScienceDirect Journal of Environmental Radioactivity journal homepage: www.elsevier.com/locate/jenvrad Meteoric 10 Be in aerosol filters in the city of Seville S. Padilla a,b,* , J.M. López-Gutiérrez a,c , G. Manjón a,d , R. García-Tenorio a,d , J.A. Galván a,d , M. García-León a,e a Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092, Seville, Spain b LEMA. Instituto de Física, Universidad Nacional Autónoma de México (UNAM), CP 045010, Ciudad de México, México c Dpto. de Física Aplicada I, Escuela Universitaria Politécnica, Universidad de Sevilla. Virgen de Africa 7, 41011, Seville, Spain d Dpto. De Física Aplicada II, Escuela Superior de Arquitectura, Universidad de Sevilla. Av. Reina Mercedes 2, 41012, Seville, Spain e Dpto. de Física Atómica Molecular y Nuclear, Universidad de Sevilla. Reina Mercedes s/n, 41012, Seville, Spain ARTICLE INFO Keywords: AMS Aerosol filter Cosmogenic radionuclides Radiochemical procedure Concentration of meteoric 10 Be ABSTRACT Cosmogenic radionuclides in the one-million-year half-life range, like 10 Be, find application fields in several Sciences. They are powerful tools in Geology and Geochronology, as they are very important tracers on the Earth, being utilized as chronometer. Meteoric 10 Be (T 1/2 = 1.39 × 10 6 y) associated to aerosols can be used as a tracer of atmospheric processes and specifically as indicators of the cosmogenic interactions in lower Stratosphere, upper Troposphere, the air exchange between both and deposition processes on the Earth surface. The applications of 10 Be are even more relevant when combined with other radionuclides such as 26 Al. In order to provide new data about concentration 10 Be in this type of samples, the first atmospheric air filters in Spain have been analysed. Values around 10 4 at/m 3 (atoms per cubic meter of air) for 10 Be have been obtained. Due to the location and the features of the sampling site (urban area, at sea level and mid latitude), a new radiochemical procedure was designed and developed in our laboratory for the Accelerator Mass Spectrometry (AMS) mea- surement of 10 Be in this kind of samples. The samples were measured in SARA, the 1 MV AMS system at Centro Nacional de Aceleradores (CNA). 1. Introduction The main constituents of earth's atmosphere are Nitrogen (78%), Oxygen (21%) and Argon (1%). The interaction of cosmic rays with isotopes of these elements produces 10 Be mainly by spallation reactions with Nitrogen due to its higher concentration. 10 Be is a potential tracer operating over time scales of up to 10 7 years (Graly et al., 2010). This radionuclide is very scarce in nature and is found in the same places where it is produced as consequence of cosmic rays in the atmosphere, water, soil or rocks. It is primarily produced in the lower stratosphere and upper troposphere. The average residence time in the atmosphere ranges from the order of two weeks in the troposphere to several years in the stratosphere depending on the altitude where it is produced (troposphere or stratosphere). As a result of stratosphere-troposphere exchange as well as deposition, the 10 Be concentrations on the surface and the deposition fluxes can be influenced. Once deposited on the surface, meteoric 10 Be is adsorbed onto particles only if the coexisting solution pH exceeds a value of 6 (von Blanckenburg et al., 2012). Sedimentary systems can therefore record both the long term deposi- tion of meteoric 10 Be and the subsequent fate of the isotope due to the chemical leaching, illuviation, erosion or soil mixing. The meteoric 10 Be concentration on the earth's surface is the result of the production, transport in atmosphere and its deposition (Ebert et al., 2012; Graly et al., 2010; Masarik and Beer, 1999). The advantages of the meteoric variety of 10 Be over the in situ-produced nuclide lie in its higher con- centrations, requiring smaller sample amounts, its applicability to quartz-free lithologies, and the possibility to determine denudation rate time series in fine-grained sedimentary deposits (Padilla et al., 2018; von Blanckenburg et al., 2012; Willenbring and von Blanckenburg, 2010). Meteoric 10 Be has been applied extensively to different problems in the last decades. The study in rain waters, surface firns, ice cores and atmospheric or aerosols filter samples provides important information related with to production and distribution in the atmosphere. Beryllium-10 is also used to study atmospheric mixing, stratosphere- troposphere exchange and seasonal variations, which can provide the https://doi.org/10.1016/j.jenvrad.2018.10.009 Received 27 December 2017; Received in revised form 9 October 2018; Accepted 18 October 2018 * Corresponding author. Laboratorio Nacional de Espectrometría de Masas (LEMA), Dpto. Física Nuclear y Aplicaciones de la Radiación, Instituto de Física, Universidad Nacional Autónoma de México (UNAM), CP 045010, Ciudad de México, México. E-mail address: spadilla@fisica.unam.mx (S. Padilla). Journal of Environmental Radioactivity 196 (2019) 15–21 0265-931X/ © 2018 Published by Elsevier Ltd. T