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 km2. 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 (CSCA) 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 element 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.

中文翻译：

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坎帕尼亚地区（意大利南部）土壤中的潜在有毒元素：结合原始数据和成分数据

摘要 对潜在有毒元素 (PTE) 的健康影响的担忧导致全球对其在环境中的浓度水平越来越关注。土壤地球化学已被广泛用作环境监测的工具。本研究调查了坎帕尼亚地区（意大利南部）的表土地球化学，并且 (i) 可以对 PTE（As、Be、Cd、Co、Cr、Cu、Hg、Ni、Pb、Sb、Se、Sn、Tl、 V 和 Zn) 在土壤中的浓度，(ii) 能够在区域尺度上调查控制 PTE 地球化学变化的主要因素。从调查区收集了超过 7300 份表土样品，占地约 13.600 平方公里。在王水消解后，通过 ICP-MS 分析样品的 53 种元素（主要和微量元素）的假总含量。进行数据分析时考虑了原始数据及其作为 PTE 环境评估和原产地调查工具的组成性质。坎帕尼亚地区土壤中 As、Be、Cu、Pb、Sn、Tl、V 和 Zn 的中值浓度水平高于意大利和欧洲土壤。此外，所有 PTE 都超过了意大利立法规定的住宅/娱乐干预限制 (CSCA)。成分数据的变化结构已经使用成分 (clr) 双标图进行了可视化，并根据其母岩显示了各个样本的观察结果。Clr-biplot 分析使我们能够识别控制大多数土壤化学特征的地球化学过程。进行了多变量分析并确定了三个主要成分。PC1 受来自该地区主要母岩（硅质碎屑和火山碎屑）的元素的富集控制。另一方面，PC1 揭示了由 Na、K、U、Th、Zr、Ti、Tl 和 Be（clr 变量）主导的元素组合的存在，这些元素是由火山母质发育的土壤的探路者元素。第二个 (PC2) 分量很好地区分了土壤中元素的地球化学迁移率。第三个 (PC3) 分量揭示了人为关联（Hg、Sb、Pb、Sn、Au、Ag）的存在，它描述了研究区土壤地球化学的边际贡献。clr-biplot 的生成帮助我们更深入地解释了单元素空间分布模式。作为，是，锡，Tl 和 V 空间分布显示在由主要火山复合体的火山产物发育的土壤中占主导地位。我们的研究表明，由于背景浓度值相当高，Be、Sn 和 Tl 等元素在几乎整个地区自然超过了污染阈值。因此，坎帕尼亚地区不能被认为完全被这些元素污染（在这个规模上）。Co、Cd、Cr 和 Ni 在硅质碎屑母岩出现的地方更丰富。