During nuclear facility decommissioning, the release of tritiated particulate matter from contaminated stainless steel and cement poses potential dermal exposure risks for workers and nearby environments. This study investigates the transdermal behavior of tritium (3H) released from tritiated stainless steel (TSSPs) and cement particles (TCPs), two matrices differing in physicochemical composition and hydrogen-binding properties. Using in vitro Franz diffusion cells and excised human skin, 3H permeation was evaluated under intact, damaged, abraded, and decontaminated skin conditions. Intact skin provided an effective barrier, whereas compromised epidermal integrity markedly enhanced 3H diffusion and retention. Differences in 3H release kinetics between particle types were associated with their surface characteristics and mechanisms of 3H binding, solid-solution entrapment in TSSPs versus isotopic exchange and surface adsorption in TCPs. The persistence of 3H within partially damaged skin suggests potential formation of organically bound tritium (OBT), indicating localized and sustained radiobiological exposure. Importantly, simple water decontamination significantly reduced 3H permeation, supporting its practical relevance in occupational dermal protection. These findings provide insight into the material interactions and dermal safety implications of tritiated particulates, contributing to risk assessment strategies in radiological and material exposure contexts.

Cadmium sulphide (CdS) quantum dots (QDs) are semiconductor nanomaterials extensively used in optoelectronic and biomedical applications, raising concerns regarding potential health hazards associated with dermal exposure. This study investigated the size-dependent transdermal absorption of N-acetylcysteine (NAC)-capped CdS QDs using an ex-vivo human skin model and Franz diffusion cells. Three QD sizes (3.4, 5.8 and 6.7 nm) were synthesised in aqueous solution, characterised by UV-Vis and fluorescence spectroscopy, and applied to intact and damaged human skin. Cadmium permeation into the receptor fluid and accumulation within skin layers were quantified by ICP-MS, while QD distribution was qualitatively assessed by fluorescence microscopy. Intact skin effectively limited CdS QD permeation, with cadmium levels comparable to blank controls and predominant retention within the epidermis. In contrast, damaged skin exhibited a marked and statistically significant increase in cadmium penetration, strongly dependent on particle size. The smallest QDs (3.4 nm) showed the highest permeation and tissue accumulation, reaching 303 ± 135 μg/cm² after 24 h, followed by 5.8 nm QDs, whereas 6.7 nm QDs displayed minimal penetration. Fluorescence imaging confirmed enhanced epidermal and trans-epidermal localisation of smaller QDs, particularly under compromised barrier conditions. Overall, these findings demonstrate that nanoparticle size and skin barrier integrity are key determinants of CdS QD dermal absorption. The results provide relevant evidence for hazard identification and risk assessment of cadmium-based nanomaterials, especially in occupational and environmental exposure scenarios involving impaired skin integrity.

Platinum bimetallic alloys represent a promising class of catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells. Among them, Pt3Co is characterised by higher performances than bare Pt, but also by different stability, as Co leaching is known to take place during fuel cell operation. To underline differences of catalyst behaviour in real operating conditions, the evolution of bare Pt and Pt3Co catalyst nanoparticles are here compared from pristine conditions, up to catalyst activation and aging via specific break-in and Accelerated Stress Tests (ASTs) procedures, respectively. Changes in catalyst chemistry were monitored via x-ray absorption and photoelectron spectroscopies, and via SEM-EDX. Results were combined with morphology analysis carried out via small-angle x-ray scattering. Results from both operando and ex situ measurements show as for bare Pt catalyst, both particle morphology and the ratio among metal-to-oxidised Pt do not change remarkably after the break-in, and that the Electrochemically Active Surface Area (ECSA) strongly reduces due to average particle size growth from 2.28 to 6.21 nm within the first 3000 AST cycles. Conversely, in Pt3Co catalyst, Co leaching strongly affects the break-in stage, by reducing particle size and decreasing the fraction of metallic Co. During ASTs, leaching continues also after the formation of the Pt-rich skin, which formation contributes to slow down ECSA reduction, with particle size growing from 2.59 to 6.14 nm in between 3000 and 6000 cycles only.

This study investigates 49 gold solidi issued between the 4th and 5th century AD to determine their chemical composition. The coins were first catalogued by recording mass, diameter, and thickness. All specimens underwent non-destructive µ-EDXRF analysis to identify main elements, followed by semi-quantitative fineness evaluation. To validate these results, six coins were randomly micro-sampled: material was dissolved in aqua regia and analysed by ICP-AES for gold quantification and ICP-MS for high precision trace element determination. The non-destructive analyses showed consistently high gold percentages, confirming authenticity and the extensive use of this noble metal during the studied period. Two distinct groups were identified based on the XRF Pt/Pd ratio, suggesting the use of gold from different sources. Comparison of μ-EDXRF and ICP-AES gold contents shows no statistically significant differences; however, this apparent agreement should be interpreted cautiously, as it mainly reflects the limited resolving power of ICP-AES at very high gold concentrations rather than definitive evidence for the absence of surface-related effects. Trace elements analysis detected low concentrations of Cu, Sn, and Pb suggesting the use of alluvial gold for minting. The presence and correlation of terrigenous elements (Al, Ca, Ti, Cr, Mn, Fe, Ni, Zn, Sr) indicate soil as the burial site.

Abstract As the world faces growing environmental challenges, understanding the nature of microplastics—such as Low-Density Polyethylene (LDPE) and Polyurethane (PU)—and their transformation in water-based environments is necessary for predicting and mitigating their effects. In this study, we investigated their physicochemical characteristics, presence of impurities, colloidal behavior, and sorption capacity to understand better how microplastics behave and transform in the environment, including their role in transporting heavy metals. The two types of microparticles investigated fall into distinct size ranges, approximately 70 microns for PE particles and around 5 microns for PU particles. Both samples showed a spherical morphology and an evident surface micro-roughness. The elemental and thermal analysis did not show the presence of any significant metal impurities. The zeta-potential measurements as a function of pH provided insights into the dispersion behavior of microplastics (MPs) in freshwaters, suitable for the growth of Zebrafish (Egg water) and Daphnia magna (Elendt M7 Water). Both materials showed in bidistilled water negative zeta potential (ZP) at natural pH (ZP = − 51.0 ± 4.3 mV at pH = 6.6 and ZP = − 29.5 ± 1.4 mV at pH = 5.6 for LDPE and PU, respectively), justified by the presence of surface-active charged impurities. In saline media, ZP vs. pH curves were flatter, with ZP values near 0 mV, confirming the reduced colloidal stability from higher ionic strength and double-layer compression. Finally, we assessed the metal adsorption capacity to establish the role of microplastics in the transport of heavy metals in the environment. We observed selective adsorption for Cu2⁺ ions, which was both medium-dependent (more ions adsorbed in Elendt M7) and plastic-dependent, with PU showing a stronger affinity for Cu2⁺ in MilliQ and Egg water. On the contrary, both plastics showed similar adsorption capacity for Fe3⁺ ions across all media.

Elemental mercury (Hg) is routinely determined in crystalline rocks with mass fractions lower than 10 ng g ‐1 by thermal decomposition using Direct Mercury Analyzer (DMA‐80) or Lumex RA‐915+ (equipped with a PYRO‐915+ attachment) instruments, both based on atomic absorption spectroscopy. However, 223 analyses over the course of one year with DMA‐80 and cold vapour‐atomic fluorescence spectroscopy (CV‐AFS) on three reference materials (RMs) and six crystalline rocks (granite, diorite, gabbro, spinel peridotite, phlogopite‐rich peridotite, and sulfide‐rich orthogneiss) from the exposed transcrustal section of the Ivrea‐Verbano Zone and upper crustal Serie dei Laghi unit (western Alps, Italy) reveal that rock analyses using the DMA‐80 are variably affected by different internal and external biases when Hg mass fractions are below 10 ng g ‐1 . Conversely, CV‐AFS analyses are more precise, providing homogenous and repeatable results, even at ultra‐low Hg mass fractions (< 1 pg g ‐1 ). Furthermore, CV‐AFS analyses show that gabbro and spinel peridotite powders roasted for analysis by DMA‐80 still contain ~ 0.6 to ~ 1.4 ng g ‐1 of Hg, implying inefficient release of Hg from basic/ultrabasic lithologies. Therefore, we recommend the use of CV‐AFS for Hg measurements in crystalline rocks. We also propose a new Hg reference value of 3.9 ± 1.5 ng g ‐1 for the GSJ granodiorite reference material JG‐1a.

Gallium arsenide (GaAs) is a semiconductor widely used in various technological applications. This study, conducted in a research laboratory, aims to evaluate the cutaneous permeation of GaAs particles using an ex-vivo model with Franz diffusion cells. Dissolution tests indicated that gallium dissociates at higher rates than arsenic in synthetic sweat, but permeation experiments revealed that arsenic is more permeable, particularly in damaged skin conditions. After 24 h of exposure, arsenic concentrations in the receiving compartment were three times higher in damaged skin (1558 ± 546 ng/cm2) than in decontaminated skin (458 ± 144 ng/cm2), (p < 0.05). Gallium concentrations were six times higher in damaged skin (244 ± 5.29 ng/cm2) compared to decontaminated skin (37.1 ± 11.9 ng/cm2), (p < 0.05) Intact skin serves as an effective barrier, while damaged skin significantly increases the permeation of both elements. The decontamination process also enhances penetration due to impairment of the skin's lipid structure. In conclusion, GaAs particles can release arsenic and gallium that penetrate and permeate the skin. These findings highlight the importance of preventive measures in occupational settings to ensure adequate protection.

Occupational exposure to metal-containing particles can pose significant risks to skin health, particularly in environments where materials such as stainless steel and cement are handled. This study evaluates the effectiveness of simple aqueous cleansing methods-water and soapy water-for removing metals from the skin after exposure to stainless steel particles (SSP) and cement dust, with the aim of informing dermal decontamination practices. Using an in vitro skin permeation model with Franz diffusion cells, we assessed the extent of metal absorption following exposure, with decontamination applied 15 min post-contact. Quantification of permeated metals was performed via ICP-MS. Notably, soapy water significantly reduced dermal retention of lead (Pb) from cement dust, from 305 ± 111 ng/cm2 (untreated) to 7.74 ± 0.7 ng/cm2 (p < 0.05). Conversely, the same procedure increased skin retention of nickel (Ni) and chromium (Cr), suggesting a wash-in effect. For SSP exposure, soapy water was effective in reducing permeation of all tested metals. These findings emphasize the need for tailored skin cleansing strategies and contribute to the development of protective and cleansing formulations aimed at mitigating metal-induced skin toxicity.

In the field of tissue engineering, the use of core-shell fibers represents an advantageous approach to protect and finely tune the release of bioactive compounds with the aim to regulate their efficacy. In this work, core-shell electrospun polycaprolactone nanofiber-based membranes, loaded with rifampicin and coated with silver nanoparticles, were developed and characterized. The membranes are composed by randomly oriented nanofibers with a homogeneous diameter, as demonstrated by scanning electron microscopy (SEM). An air-plasma treatment was applied to increase the hydrophilicity of the membranes as confirmed by contact angle measurements. The rifampicin release from untreated and air-plasma treated membranes, evaluated by UV spectrophotometry, displayed a similar and constant over-time release profile, demonstrating that the air-plasma treatment does not degrade the rifampicin, loaded in the core region of the nanofibers. The presence and the distribution of silver nanoparticles on the nanofiber surface were investigated by SEM and Energy Dispersive Spectroscopy. Moreover, SEM imaging demonstrated that the produced membranes possess a good stability over time, in terms of structure maintenance. The developed membranes showed a good biocompatibility towards murine fibroblasts, human osteosarcoma cells and urotheliocytes, reveling the absence of cytotoxic effects. Moreover, doble-functionalized membranes inhibit the growth of E. coli and S. aureus. Thanks to the possibilities offered by the coaxial electrospinning, the membranes here proposed are promising for several tissue engineering applications.

Proton Exchange Membrane water electrolyzer (PEMWEs) are expected to play a pivotal role in supporting the energy transition due to their efficiency and capabilities to handle dynamic loads, which makes them suitable for integration with renewable energy sources. This work presents experimental tests on a 2 kW PEM electrolyzer stack operating at 100kPa, with an active area of 28.3 cm 2 and 15 cells connected in series implemented at the University of Trieste Energy System Lab. The overall activity, carried out in collaboration with ENPHOS s.r.l., aims also to develop a test bench for the performance characterization of the stack and the balance of plant components. In this paper the authors focus on the description of the plant and the preliminary stack tests. The methodology to characterize the performance of the stack consists of a first polarization curve to assess the beginning of life performance, then start-stop cycles are applied to evaluate possible initial degradation of the performance detectable by polarization curve variations. The test rig results to be suitable to test the performance of the stack. The preliminary experimental data show the stack efficiency is 60% at low load (56 kWh/kg) and decreases to 40% at the maximum load (2 kWel). There was no appreciable degradation in terms of efficiency from the beginning and the end of the tests.

Workers involved in the decommissioning and removal of radioactive material from nuclear power plants can come into contact with tritiated dust from stainless steel. This study aimed to investigate metal penetration and permeation after skin contamination with these particles. Static diffusion Franz cells were used with intact, damaged, or broken human skin. Stainless steel particles 316 L were applied to the donor phases, and the receiving solutions were collected at regular intervals for 24 h to determine the amount of metals that penetrated the skin. The effectiveness of the decontamination procedure was investigated after 30 min using water and soap. The metal content in the skin was evaluated after 24 h of exposure. Metals detected were Ni, Cr, Co, Mn, Cu, Mo. For Ni, Mn, and Cu, we found a significant increase in metal permeation in all treated cells compared with the blank (p < 0.02). For Co and Cr, permeation through the skin was significant only in the decontaminated and broken cells (p < 0.05). Decontaminated skin presented higher metal permeation for Ni, Co and Cu compared to intact skin (p < 0.05) while broken skin presented, as expected, the higher permeation profile (p <0.05) for all metals. The metal that was more represented inside the skin was Cr, with more than 15 mu g/cm(2) for intact skin. Ni inside the skin reached the 10.2 +/- 8.5 mu g/cm(2) for intact skin. Overall, the levels of metals in the receiving solution were very low in the case of intact and damaged skin contact, and the metal levels significantly increased only in the case of broken and decontaminated skin. More relevant appears Skin content with sensitizing metals (Ni, Cr, and Co) that can induce allergic sensitization or cause allergic contact dermatitis in subjects already sensitized.

The potential impact of decommissioned mining areas on environmental quality is of major concern for local communities, posing a risk to water resources and human health. This study aims to investigate the impact of extraction activities on the surface environment by evaluating the occurrence of metal(oid)s, including potentially toxic elements (PTEs, i.e. As, Cd, Fe, Tl, Zn, Pb) and critical elements (As, Ge), at the Zn-Pb Raibl mining area (northeastern Italy). Elevated concentrations of metal(oid)s are found near mine waste heaps (< 100 mg/kg for Tl, Sb, Cd, Ge; > 1,000 mg/kg for As; > 1% for Pb and > 10% for Zn and Fe), which are made up of flotation tailings and waste rocks scattered around the mining village and stored in the tailings impoundments. Conversely, upstream from the mine, the environment is largely uncontaminated. According to the results, total and leachable metal(oid) concentrations are positively correlated. Tailings (65.1-754 mg/kg of Tl) are identified as the primary source of leachable Tl (11.4-255 mg/kg) and metal(oid)s are generally more mobile in organic-rich soils, suggesting increased metal(oid) mobility with soil ageing due to low soil pH and potential soluble organometallic complexes. Furthermore, the findings suggest that reprocessing of mine tailings could be a potential solution to recover valuable elements together with residue backfilling. Lastly, results from this study highlight how crucial mining site management is to limit PTE dispersion and reducing risks to the environment and public health.

Human exposure to airborne particulate matter (PM), particularly its metal content, represents a growing public health concern due to its potential toxicological effects. While inhalation is generally considered the main exposure route, dermal absorption remains insufficiently explored. This study examined the in vitro percutaneous penetration of selected metals (As, Cd, Cr, Cu, Mn, Mo, Ni, Pb, V) from certified urban road dust (NIST SRM® 1649b) using human skin under both intact and abraded conditions. The particles were applied as a 1 % w/v suspension in artificial sweat medium (pH 4.5), and Franz diffusion cells were used to evaluate metal permeation over 24 h. Complementary solubility tests in simulated sweat solution buffered topH 4.5 and 6.5 showed negligible pH dependence. Scanning electron microscopy revealed submicron primary particles (mean diameter 1.19 ± 0.78 μm) with a high tendency to form agglomerates, accounting for discrepancies with the hydrodynamic size reported in the SRM certificate. No detectable skin absorption was observed for Cd, Cr, and Cu, while the remaining metals showed enhanced permeation in damaged skin, confirming the role of barrier disruption in facilitating transdermal transport. Ni, Pb, and Mn exhibited the highest permeation levels, raising concern due to their sensitizing and toxic potential. These findings provide novel insights into the dermal bioavailability of PM-associated metals and highlight the importance of including skin exposure as a relevant pathway in environmental health risk assessments, especially for populations with compromised skin integrity or in high-exposure occupational settings.

The Timavo River estuary (northern Adriatic Sea) is characterised by strong thermohaline stratification that keeps the deep waters hypoxic. The consequence is an harmful algal bloom at the surface in summer that can be mitigated with a forced aeration system installed at the bottom to improve water oxygenation. The nutrient and metal(loid) cycle was investigated, before and during reoxygenation, using an in situ benthic chamber coupled with sampling and analyses of the water column, sediments and porewater. Dissolved oxygen (DO) decreased along the water column and quickly within the benthic chamber when aeration was not in operation, resulting in hypoxia (2.29 mg L-1) at the bottom and consequent increase in nutrient and metal(loid) concentrations. In contrast, DO levels increased during the activation of the forced aeration system, which proved effective in mitigating oxygen depletion and the efflux of metal(loid)s and nutrients into the overlying water.

We evaluated GaAs nanoparticle-concentrations in the air and on skin and surfaces in a research facility that produces thin films, and to monitored As in the urine of exposed worker. The survey was over a working week using a multi-level approach. Airborne personal monitoring was implemented using a miniature diffusion size classifier (DiSCMini) and IOM sampler. Environmental monitoring was conducted using the SKC Sioutas Cascade Impactor to evaluate dimensions and nature of particles collected. Surfaces contamination were assessed analyzing As and Ga in ghost wipes. Skin contamination was monitored using tape strips. As and Ga were analyzed in urines collected every day at the beginning and end of the shift. The greatest airborne exposure occurred during the cutting operations of the GaAs Sample (88883 np/cm3). The highest levels of contamination were found inside the hood (As max = 1418 ng/cm2) and on the laboratory floor (As max = 251 ng/cm2). The average concentration on the worker's skin at the end of the work shift (3.36 ng/cm2) was more than 14 times higher than before the start of the shift. In weekly urinary biomonitoring an average As concentration of 19.5 µg/L, which was above the Società Italiana Valori di Riferimento (SIVR) reference limit for the non-occupational population (2.0 - 15 µg/L), but below the ACGIH limit (30 µg/L). Overall, airborne monitoring, surface sampling, skin sampling, and biomonitoring of worker confirmed the exposure to As of workers. Systematic cleaning operations, hood implementation and correct PPE management are needed to improve worker protection.

X-Ray Fluorescence (XRF) analysis is widely employed in the field of cultural heritage due to its nondestructive nature. mu-EDXRF was used to study 29 Sasanian drachmas from a private collection at the Department of Humanities, University of Trieste. The coins were issued between 499 and 628 AD, during the reigns of four Sasanian kings (Kawad I, Khosrow I, Hormizd IV, and Khosrow II). This study aimed to determine the elemental composition of the alloy's surface, assess the coins' fineness, and identify potential forgeries or signs of devaluation. Eight XRF spectra were acquired for each sample, revealing a primary composition of Ag, with traces of Cu, Au, and Pb. Semi-quantitative analysis showed Ag content exceeding 95% in nearly all coins, with two suspected forgeries identified (coin no. 13 minted during the reign of Hormizd IV and coin no. 18 from the reign of Khosrow II). Five drachmas from Khosrow II's reign, marked with the inscription "afid", exhibited Ag content above 99 %, supporting the historical hypothesis of superior quality compared to other drachmas from the same period. Finally, the %Au and the presence of Pb provided further indications on the origin of Ag, allowing hypotheses on the mineral sources. (c) 2024 The Author(s). Published by Elsevier Masson SAS on behalf of Consiglio Nazionale delle Ricerche (CNR). This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Objective: Barrier creams (BCs) are marketed as locally applied medical devices or cosmetic products to protect the skin from exposure to chemicals and irritants. Generally, the mechanism of action of such products is mainly due to the formation of a superficial thin film between the skin and the irritant or sensitizer, thus reducing or totally blocking the cutaneous penetration of such agents. Specifically, studies focusing on the effectiveness of commercial protective creams to prevent nickel cutaneous penetration are extremely scarce. The aim of the current work, therefore, is to evaluate the protective role of a commercially available barrier cream for nickel and compare the results with a simple moisturizing, following exposure to Ni powder.Methods: Marketed BCs were evaluated and tested. Human skin absorption of Ni was studied in vitro using static Franz diffusion cells.Results: Our results demonstrate that the application of both formulations caused a reduction of Ni inside the skin (8.00 +/- 3.35 mu g cm-2 for the barrier cream and 22.6 +/- 12.6 mu g cm-2 for the general moisturizing product), with the specialized barrier cream being statistically (p = 0.015) more efficient on forming a protective barrier, thus evidencing the importance of some ingredients in such formulations on the nickel dermal accumulation.Conclusions: The composition of the formulations based on film-forming or chelating agents may play an imperative role in reducing the cutaneous penetration of Ni.

Welding operations originate micro and nanoparticles represented by metal oxides, unoxidized metals and compounds, such as fluorides and chlorides. Welding fumes exposure is associated to lung cancer, chronic bronchitis, asthma and early Parkinson disease. Ultrafine (nanosized) particles in welding fumes are considered a risk factor in terms of occupational exposure: when inhaled, they are efficiently deposited in all regions of the respiratory tract and can translocate to other target organs as brain and systemic circulation. The study of nanoparticles emissions during welding can help to understand effects related also to new-engineered nanoparticles exposure.In our study two real sources of Gas Tungsten Arc Welding (GTAW) fume particles, collected in an automotive plant, were characterized by means of a transmission electron microscope coupled with an energy-dispersive X-ray analytical system (TEM-EDS) and compared to a zone of the plant far from the two sources used as a reference background. The particles sampled during the automatic GTAW process were mainly constituted by iron/manganese oxide with a mean diameter of 47 nm, followed by smaller iron oxide nanoparticles (21 nm). During the manual welding process mostly aggregates with larger diameters that showed an X-ray spectrum characteristic of different kinds of silicates were found. Iron and cobalt oxides nanoparticles were present only inside bigger aggregates mainly composed of aluminum and titanium oxides.This study confirms that welders are exposed to nano- and submicron particles and that iron/manganese oxide nanoparticles are the most representative in automatic process, despite the low concentration of manganese in welding wires (1–2%). Our results help to understand hazard related to welding fumes exposure and possible effects of nanoparticles on lung, brain and systemic circulation.

There is an increase of application of Nickel in the form of nanoparticles (NiNPs) in several fields including modern metallurgy, bioengineering, and medicine. Such growth of the areas of application is actually accompanied with an increase of exposure to Nickel, thus an intensification of the negative effects, the most frequent being the allergic contact dermatitis. Indeed, due to their smaller size, and therefore their higher surface area, NiNPs can release more Ni ions compared to bulk material, that can penetrate and permeate through the skin. To reduce the Ni cutaneous penetration, barrier creams (BC) are applied on the skin surface. There is little information, however, on the efficiency of such commercial protective creams on decreasing Ni cutaneous penetration. For this reason, the objective of the current study was to investigate the protective role of one commercially available formulation for Ni (Nik-L-Block™ containing a chelating agent) and one moisturizing cream (Ceramol 311 basic cream without chelating agent), following exposure to NiNPs, using in vitro Franz cells, as well as the cytotoxicity of NiNPs in primary human dermal fibroblasts was studied. Our results demonstrated that although both tested formulations can decrease Ni accumulation in the skin (4.13 ± 1.74 μg/cm2 for Nik-L-Block™ and 7.14 ± 1.46 μg/cm2 for Ceramol 311 basic cream); there are significant differences between the two creams (p = 0.004). Based on the experimental evidence, we therefore conclude that the composition of such formulations has an imperative role for dermal uptake of Ni. Finally, NiNPs showed no cytotoxic effect on cultured human dermal fibroblasts after 24 and 72 h.

Decommissioned mines represent a worldwide concern due to the potential long-term effects related to the dispersion of potentially toxic elements (PTEs) in the environment. In this study, 176 water samples were collected in the period 2018-2021 at the carbonate-hosted Pb-Zn Raibl mine which is affected by neutral mine drainage (NMD). The post-flotation tailings are the main source of PTEs (Zn, Pb and especially Tl) in the river drainage system. Compared to other dissolved PTEs (Zn, Pb, Cd), Tl was found to be more mobile, reaching concentrations up to 120 mu g L-1 in waters flowing in the tailings impoundments. Modelling results suggest that Tl is mainly present in the Tl(I) ionic and mobile form thus suggesting that relevant natural attenuation processes for this element are not expected in the investigated area. In contrast, Zn and Pb attenuation pathways appeared to be governed by pH-dependent speciation and sorption processes, whereas elevated Zn concentrations were likely also limited by hydrozincite precipitation. Metalloids such as As and Sb were almost entirely released into the slightly alkaline waters of the mine drainage system, which are generally characterised by longer residence time or standing waters whereas As and Sb concentrations were negligible in the tailings-seepage waters. However, intense rainy events may increase PTE concentrations of one order of magnitude, especially in the tailings impoundment groundwater as a result of a rise in the water table, and PTE total dissolved loads of three orders of magnitude, in the main stream during high flow events, thus representing the most critical factor in regulating the remobilisation and downward dispersion of PTEs in the river drainage system.