This study proposed an approach to determine the geochemical baseline values in topsoils. The chosen study area is Sicily (Italy), a region characterized by significant lithological heterogeneity. Eighty-three topsoil samples were collected at several sites away from potential anthropogenic pollution sources. The concentrations of potentially toxic elements (As, Cd, Cr, Cu, Mo, Pb, Sb, V, and Zn) were quantified via inductively coupled plasma (ICP-MS). The elements showed median concentrations in the range 68.8-0.23 μg g^-1 and the trend of abundance was: Zn > V > Cr > Cu > Pb > As>Mo > Sb > Cd. Regional geochemical baseline values for trace elements were determined using statistical methods (Me±2MAD; P95 and UTL95-95). The use of UTL95-95 was found to be the most suitable, obtaining appropriate geochemical baseline values for the entire region, regardless of lithology. The spatial distribution of the elements was determined by stochastic simulations on a convex-concave boundary with a resolution of 5 km, obtaining detailed geochemical maps that predict the distribution of concentrations of each element even in unsampled areas. The results of this study provide a methodology for a more correct assessment of the environmental contamination status of soils.

This study presents a comprehensive investigation of the geochemical baseline values and the spatial distribution of major, trace elements, and rare earth elements in the unpolluted soils of Sicily region. The concentrations of elements were quantified by ICP-OES and ICP-MS. The distribution patterns of major and trace elements are closely linked to the geological features of the area. The major elements Fe, Ca, Al, Mg, and K exhibit the highest concentrations. The order of abundance for trace elements follows this trend: Ba, Sr, Zn, V, Cr, Cu, Rb, Ni, Pb, B, Li, Co, As, Mo, U, Sb, Se, Cd, and Bi. Regional geochemical baseline values were calculated using the UTL95 - 95 method with BCA bootstrap, demonstrating that the regional approach provides a more accurate assessment compared to European and Italian threshold values. A geostatistical approach was used to produce spatial geochemical maps, which allow the prediction of element distributions in unsampled areas. This integrated approach establishes a benchmark for more detailed studies on environmental risk assessment, providing a solid foundation for identifying and understanding natural and anthropogenic geochemical anomalies in the soils of the Sicily region.

This study investigates the distribution and mobility of metals and metalloids (M&Ms) in soils, rocks, and groundwater within the geologically complex southwestern region of Sicily. The study aims to highlight how natural sources, like rocks and soils, can release elements potentially harmful to human health. It underlines their dual role as both natural reservoirs and active sources of M&M release, driven by leaching processes influenced by physicochemical factors such as pH and redox potential (Eh). Lithological characteristics significantly influence the retention and release of elements, with clay-rich formations exhibiting higher immobilization capacity. However, environmental parameter variations can enhance element mobilization, increasing bioavailability and the risk of groundwater contamination. Water quality analyses reveal regulatory exceedances for As, B, Ni, and Be, underscoring potential health and ecological risks. Concurrently, microbiological investigations identify diverse microbial communities capable of altering the oxidative states of specific elements through oxidation and reduction processes, further influencing their mobility. This study underscores the importance of understanding natural sources of M&Ms and their interactions with geochemical and microbiological processes for effective environmental risk assessment. The findings provide a foundation for developing integrated and sustainable water resource management strategies to mitigate contamination risks and safeguard ecosystems and public health.

Dense nonaqueous phase liquids (DNAPLs) are known to be denser than water and immiscible with other fluids. Once released into the environment, they migrate downward through the variably saturated zone, causing severe damage. For this reason, it is essential to properly develop a rapid response strategy, including predictions of contaminant migration trajectories from numerical simulations modeling. This paper presents a series of simulations of free-product DNAPL extraction by means of a purpose-designed pumping well. The objective is to minimize the environmental impact caused by DNAPL release in the subsurface, estimating the recoverable free-product DNAPL, depending on the hydraulic properties of the aquifer medium, and estimating the leaving residual DNAPL that could act as a long-term pollution source. Coupling the numerical simulations to the bacterial community characterization (through biomolecular analyses), it was verified that (i) the DNAPL recovery (mainly PCE at the study site) through a pumping well would be almost complete and (ii) the application of other remediation techniques (such as bioremediation) would not be necessary to remove the pollution source because (iii) a natural attenuation process is provided by the autochthonous bacterial community, which is characterized by genera (such as Dechloromonas, Rhodoferax, and Desulfurivibrio) that have metabolic pathways capable of favoring the degradation of chlorinated compounds.

Prolonged droughts combined with intensive groundwater abstraction can lead to severe aquifer depletion and degradation of water quality, especially in coastal settings prone to seawater intrusion. We investigated groundwater storage depletion and salinization in the Marsala–Mazara del Vallo coastal aquifer, southwestern Sicily (Italy), during the recent drought period from January 2024 to May 2025, with a cumulate precipitation of approximately 600 mm, well below long-term average. Furthermore, we evaluated the impact of having in place two managed aquifer recharge schemes infiltrating tertiary treated wastewater during the winter time along with that of using the reclaimed water in the irrigation season.A density-dependent groundwater flow and solute transport model was developed using the SEAWAT code, integrated within the FREEWAT-Q3 platform. The model couples groundwater flow with chloride transport to simulate seawater intrusion under transient pumping conditions. We calibrated the model using observed groundwater heads and electrical conductivity data (transformed in chloride concentrations). The implemented model includes meteoric recharge, river–aquifer interactions, coastal wetlands, and extensive groundwater abstractions for drinking water and irrigation purposes.Results show reduced recharge and sustained pumping during drought significantly depleted groundwater storage, reverse hydraulic gradients, and enhance inland migration of saline water, particularly in low-lying sectors of the coastal aquifer. Measured electrical conductivity trends and simulated chloride distributions confirm progressive seawater encroachment, particularly along the coastline and in heavily pumped areas. Conjunctive simulation of tertiary treated wastewater reuse for irrigation, substituting groundwater, and recharging the aquifer using such reclaimed water, when not used for irrigation, demonstrates non-conventional water resources may alleviate the impact of drought periods.Overall, our simulation results underline the need for drought-adapted groundwater management strategies, including seasonal pumping regulation, use of non conventional waters, and continuous monitoring of groundwater levels and salinity.

Trace element contamination represents a persistent environmental issue, particularly in industrialized areas where anthropogenic emissions overlap with natural geochemical backgrounds. This study investigates the atmospheric deposition of trace elements in the Milazzo district (Italy), which is characterized by intense industrial activity. Pinus pinea L. needles were used as biomonitors to assess the spatial distribution and sources of trace elements, combined with lead isotopic analysis for source apportionment. Forty needle samples were analyzed by ICP-OES and ICP-MS for Ca, K, Mg, Na, P, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, V, Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, while 25 samples were selected for Pb isotope ratio determination (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb). Multivariate statistical analyses identified source groups related to industrial and petrochemical emissions, vehicular traffic, crustal resuspension, and mixed combustion processes. Elevated concentrations of As, Cr, Mo, Ni, Pb, Sb, V, and Zn ranged from 16.6 μg g⁻¹ (Zn) to 0.09 μg g⁻¹ (Sb), with the following order of abundance: Zn > Cr > Ni > Pb > Mo > V > As > Sb; these elements were found near industrial facilities and urban areas. Enrichment Factor calculations indicated strong anthropogenic contributions to Cd, Cu, Mo, Sb, V, and Zn, with EF > 10, ranging from 10 (Cd) to 60 (Zn), whereas Al, Fe, and Ti exhibited EF values between 0.5 and 2, reflecting geogenic origins. Pb isotopic ratios (²⁰⁶Pb/²⁰⁷Pb = 1.153–1.192 and ²⁰⁸Pb/²⁰⁶Pb = 2.063–2.108) revealed mixing between industrial emissions and the local geological background, with limited influence from historical gasoline-derived Pb. This integrated geochemical and isotopic approach can effectively identify contamination sources in complex industrial environments.