Contents lists available at ScienceDirect Journal of Geochemical Exploration journal homepage: www.elsevier.com/locate/gexplo Potentially toxic elements in soils of Campania region (Southern Italy): Combining raw and compositional data Daniela Zuzolo a, ⁎ , Domenico Cicchella a , Annamaria Lima b , Ilaria Guagliardi c , Pellegrino Cerino d , Antonio Pizzolante d , Matar Thiombane e , Benedetto De Vivo f,g , Stefano Albanese b a Department of Science and Technology, University of Sannio, 82100 Benevento, Italy b Department of Earth, Environment and Resources Sciences, University of Naples Federico II, 80126 Napoli, Italy c National Research Council of Italy, Institute for Agriculture and Forest Systems in the Mediterranean (CNR-ISAFOM), Rende (CS), Italy d Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici 80055, Italy e Haemers technologies, Chaussée de Vilvorde, Brussels, Belgium f Pegaso University, 80132 Napoli, Italy g Virginia Tech, Blacksburg, VA, USA ARTICLE INFO Keywords: PTEs Campania region Compositional data Soil contamination Soil geochemistry ABSTRACT Concern about health effect of Potentially Toxic Elements (PTEs) has led to an increasing global attention about their concentration levels in the environment. Soil geochemistry has been widely used as a tool for environment monitoring. This study investigates topsoil geochemistry of Campania region (Southern Italy) and (i) allows a reliable overview of the PTEs (As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn, Tl, V and Zn) concentration in soils, (ii) enable the investigation of the main factors governing PTEs geochemical variation on a regional scale. Over 7300 topsoil samples were collected from the survey area, which occupies an area of about 13.600 km 2 . Samples were analyzed for pseudo-total content of 53 elements (major and trace elements) by ICP-MS after aqua regia digestion. Data analysis was performed taking into account both raw data and their compositional nature as a tool for the PTEs environmental evaluation and origin investigation. As, Be, Cu, Pb, Sn, Tl, V and Zn in soils of Campania region show higher median concentration levels than Italian and European ones. In addition, all PTEs exceed the residential/ recreational intervention limit (CSC A ) set by Italian legislation. The variation structure of compositional data had been visualized using compositional (clr) biplots and displaying the individual sample observations according to their parent rock. Clr-biplot analysis allowed us to recognize geochemical processes controlling most of soil chemical signatures. Multivariate analysis has been performed and three principal components were determined. PC1 is controlled by enrichment of elements deriving from dominant parent rocks of the area (siliciclastics and volcanoclastics). On the other hand, PC1 reveals the presence of an elemental association dominated by Na, K, U, Th, Zr, Ti, Tl and Be (clr variables), which are pathfinder element of soils developed from volcanic parent material. The second (PC2) component well discriminates the geochemical mobility of the elements in soils. The third (PC3) component reveal the presence of an anthropogenic association (Hg, Sb, Pb, Sn, Au, Ag) which depict a marginal contribution in soil geochemistry of the study area. The generation of clr-biplot helped us in a deeper interpretation of single ele- ment spatial distribution patterns. As, Be, Sn, Tl and V spatial distribution shows dominance in soil developed from volcanic products of the main volcanic complexes. Our study showed that element such as Be, Sn and Tl naturally exceed the contamination thresholds in almost the entire territory, due to a quite elevated background concentration values. Hence, Campania region con not be considered entirely contaminated (at this scale) by such elements. Co, Cd, Cr and Ni are more abundant where siliciclastic parent rocks occur. 1. Introduction Potentially toxic elements are naturally occurring, ubiquitous che- micals in the soil environment which essentially originate from the weathering of parent materials and pedogenetic processes (Tazikeh et al., 2018) giving rise to spatial variability of their concentration le- vels. Nevertheless, population growth, rapid urbanization, exponential consumption of resources (land, food, water, air, fossil fuels and https://doi.org/10.1016/j.gexplo.2020.106524 Received 12 October 2019; Received in revised form 3 March 2020; Accepted 3 March 2020 ⁎ Corresponding author. E-mail address: dzuzolo@unisannio.it (D. Zuzolo). Journal of Geochemical Exploration 213 (2020) 106524 Available online 05 March 2020 0375-6742/ © 2020 Elsevier B.V. All rights reserved. T