Human biomonitoring of mercury (Hg) exposure commonly relies on blood and hair measurements, often assuming a stable conversion ratio between these matrices. However, this assumption neglects dynamic toxicokinetic processes governing Hg distribution and elimination. Here, we characterized the distribution, determinants, and toxicokinetic implications of the hair-to-blood total Hg ratio in 453 individuals from Amazonian riverine communities chronically exposed to methylmercury (MeHg). Total Hg (THg) was determined in blood and hair, Hg speciation in hair by LC-ICP-MS, and selenium (Se) in blood was measured by ICP-MS. Model-based estimates of MeHg intake and Hg excretion were derived, and linear, non-linear, and multivariable analyses were applied. Blood and hair THg were strongly correlated (R = 0.86, p < 0.0001), confirming hair as a robust biomarker of chronic exposure. However, the hair-to-blood ratio showed high inter-individual variability (median 303; range 73.6-2132) and a significant inverse association with blood THg (β = -0.394, p < 0.001), indicating non-linear partitioning. Blood Se levels were elevated and positively associated with the ratio (β = 1.081, p < 0.001). Estimated MeHg intake exceeded the USEPA reference dose by over tenfold. These findings demonstrate that the hair-to-blood Hg ratio is a dynamic biomarker influenced by exposure intensity and potentially by Se status.

Mercury (Hg) is a highly toxic and persistent environmental pollutant whose accurate monitoring remains challenging due to limitations in existing diffusive gradients in thin films (DGT) binding materials, including insufficient selectivity, complex synthesis, and sustainability concerns. In this study, we report the first application of graphitic carbon nitride (GCN) nanosheets as a metal-free and sustainable binding material for Hg & sup2;(+) monitoring in DGT systems, addressing key limitations of current approaches. Few-layer GCN nanosheets were synthesized via thermal polymerization followed by protonation-assisted exfoliation and comprehensively characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman spectroscopy, and scanning electron microscopy (SEM). These analyses confirmed the formation of a structurally stable, nitrogen-rich framework with abundant coordination sites. The GCN-agarose (AG-GCN) composite binding layer demonstrated high mercury binding efficiency (>90%) at environmentally relevant concentrations (2.5-10 ng/mL) and near-neutral pH, attributed to strong coordination between Hg & sup2;(+) ions and electron-donating nitrogen sites within the heptazine structure. Compared to conventional DGT binding phases, the proposed system offers enhanced sustainability, metal-free composition, and strong affinity toward mercury, highlighting its potential for next-generation passive environmental monitoring and advanced nanomaterial-based sensing platforms.

Based on toxicological evidence, human exposure to phthalates (PHs) and diisononylcyclohexane-1,2-dicarboxylate (DINCH) may contribute to adverse health effects, especially during vulnerable developmental stages. To support the exposure assessment for this group of endocrine disruptors, we developed and validated a method for the analysis of 14 PH and 3 DINCH metabolites in human urine and maternal milk, applied the method in a pilot study, and identified crucial obstacles in the path of establishing maternal milk as a routine matrix in human biomonitoring. Urine and milk samples were extracted with solid-phase extraction (SPE) and QuEChERS salts, respectively, and analysed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method accuracy was confirmed for urine samples via a certified standard reference material and the G-EQUAS intercomparison programme. We identified a need for sampling protocols, reference materials, and external method verification schemes in order to establish maternal milk as a routine matrix. Finally, the method was tested for its applicability in a pilot biomonitoring study on 30 paired urine and milk samples from lactating mothers, with medians ranging from <LLOQ - 15 µg/L in urine and <LLOQ - 16 µg/L in maternal milk and generally higher detection rates in urine. Furthermore, the results indicate extensive monoester formation under cooled storage conditions, resulting in potentially high infantile exposure to phthalate monoesters for which, to date, no guidance values exist despite their demonstrated toxicity.

BACKGROUND:Certified reference materials (CRMs) for mercury speciation of biological fluids have hitherto been limited to frozen or cold-storage types, which impedes the participation of laboratories in tropical or remote regions. Existing CRMs often do not fully meet user needs, particularly regarding storage stability and concentration relevance. RESULTS:Using pooled Japanese human blood, we developed a freeze-dried, ambient-stable blood CRM, with certified values of 6.16 μg L-1 for total mercury (THg) and 5.46 μg L-1 for methylmercury (MeHg, as Hg). These concentrations are congruent with median exposure levels in fish-consuming populations (e.g., small island states and riverine Amazonian communities) derived from global biomonitoring data. Homogeneity, stability, and traceability were validated through inter-laboratory comparisons and rigorous uncertainty assessment. SIGNIFICANCE:This ambient-stable blood CRM broadens global access to high-quality QA/QC of mercury speciation, especially in regions lacking cold-chain infrastructure. It contributes to capacity building under the Minamata Convention and strengthens interlaboratory comparability. Registration in COMAR and international collaborative deployment are under active development, enhancing the global infrastructure for mercury biomonitoring.

This study analysed urinary mercury (U-Hg) concentrations in 1412 Slovenian children across four human biomonitoring campaigns conducted between 2007 and 2024. Median U-Hg levels declined from 0.76 ng mL−1 (0.72 µg g−1 creatinine) in the 2007 PHIME cohort to 0.22 ng mL−1 (0.21 µg g−1 creatinine) in the 2018–2024 SLO-HBM-II cohort, paralleling a decrease in the prevalence (from 65 to 3

Monitoring toxic elements has a long tradition in Slovenia due to historical mining. More recently, attention has shifted to essential elements, since both deficiencies and excesses can harm health. Regular monitoring of (non-)essential elements supports risk assessment and policymaking. While urine and blood are common biomonitoring matrices, hair offers a non-invasive alternative that reflects exposure over several months, though standardised methodologies for hair analysis remain limited. This study aimed to develop and validate a sensitive and robust analytical method for the determination of 29 elements in human hair, addressing key challenges in sample preparation and contamination control. We developed a sensitive and robust method for the determination of 29 elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Se, Sn, Sr, Ti, U, V, and Zn) in 3 cm segments of human hair that involves a washing procedure with acetone and Milli-Q water, microwave digestion with 65% HNO3, and analysis with Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS). Evaluation of preparation steps revealed stainless-steel scissors as a major contamination source. Glass digestion vessels were unsuitable for several elements due to high detection limits and relative standard deviations. The optimised method reduced analytical variability and improved sensitivity compared to published protocols. This validated method enables reproducible multi-elemental analysis in hair, highlights overlooked contamination risks, and is now applied in human biomonitoring studies to strengthen exposure assessment and standardisation efforts.

This study provides a review of 13 oceanographic campaigns between 2000 and 2017 to measure Hg in the Mediterranean, highlighting major findings from measurement and modelling activities during the Med-Oceanor program. The initial campaigns showed that high concentrations of RGM could be found far from industrial source regions and the observed daily variation in concentration, with peaks at midday and lower concentrations during darkness gave the first indications that photochemically mediated oxidation reactions were producing RGM in the MBL. Later atmospheric chemistry modelling studies showed the feasibility of Hg oxidation by bromine containing oxidants, which are released as a result of the acidification of sea salt aerosols in the Marine Boundary Layer (MBL). Spatial and seasonal variations of DGM were observed at different depths in the water column, with average DGM concentrations higher in the West and East Mediterranean deep and intermediate waters, than in overlaying Atlantic waters. DGM in water profiles typically increased with depth, together with nutrients and decreasing oxygen, indicating a possible bacterial and/or geogenic origin. Using measured DGM and meteorological variable values Hg fluxes can be calculated. When these are included in regional and global models they suggest that the net Hg evasion from the Mediterranean is around 30 Mg yr-1. Repetition of these campaigns should be an extremely high priority, both to continue to monitor changes in atmospheric and aquatic Hg species concentrations, but also to perform RGM detection methodology intercomparisons so that the historical data is adequately contextualised and may be used to evaluate temporal trends.

Endocrine-disrupting chemicals (EDCs), including known and unknown parent compounds, their metabolites, and transformation products, are pervasive in daily life, posing increasing risks to human health and the environment. This study employed a high-resolution mass spectrometry-based nontargeted screening approach, integrating polar (HILIC) and reversed-phase separations to expand the chemical space coverage and, supported by open-science tools and resources, evaluated urinary chemical profiles to assess internal EDC exposure. Among 106 annotated biomarkers of exposure, six exhibited significantly higher normalized intensities in patients with ovarian malignancies compared to healthy controls (p < 0.05). This suggests their greater exposure to phthalates (diethylhexyl phthalate and diethyl phthalate), pesticides (metolachlor metabolite and 4-nitrophenol), a UV filter (benzophenone-1), and an industrial byproduct (4-methyl-2-nitrophenol). These compounds may interfere with hormonal regulation, potentially contributing to cancer development. While these findings highlight potential differences in internal EDC exposure, the study primarily demonstrates the applicability of nontargeted urinary profiling for chemical exposure assessment. By providing new insights into EDCs burden and its pathological implications, this work contributes to advancing next-generation chemical risk assessment within the European Partnership for the Assessment of Risks from Chemicals initiative and supports the development of preventive strategies to mitigate environmental cancer risks.

Globally, foliar uptake of atmospheric mercury (Hg) is a key deposition pathway for terrestrial surfaces. However, diverse sampling and pre-treatment methods across studies can influence the comparability of foliar Hg concentrations and isotopic measurements, leading to biases that impact our understanding of Hg inter-compartmental exchanges at regional and global scale. In this study, we tested the effect of different sample drying and rinsing methods on foliage samples collected from three distinct locations on the tree crown of a European hornbeam (Carpinus Betulus L.). Samples were taken from Ljubljana, an urban area, and Idrija, a historically Hg-contaminated mining site, representing contrasting environments. Vertical crown stratification significantly influenced Hg concentrations, with inner canopy foliage in Ljubljana containing 46–50

Objectives: There are still limited or lacking data on the association of trace elements (TEs) with polycystic ovary syndrome (PCOS). This case–control study aimed to determine levels of essential TEs (manganese (Mn), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo)) and non-essential TEs (arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb)) in urine, whole blood, and serum to investigate a possible association with kidney and liver function, endocrine and metabolic parameters, and environmental and lifestyle sources of potential exposure and provide possible recommendations. Methods: In our case–control study, women with PCOS (n = 35) and healthy controls (n = 35) underwent clinical and ultrasonographic examination, filled in questionnaires targeting general, lifestyle, and environmental information, and provided fasting venous blood samples and first morning urine for biochemical, hormonal, and TE analysis. Multiple linear regression models were used to evaluate the association between TE levels and data obtained through questionnaires. Results: In women with PCOS, lower Mo levels in whole blood (p = 0.024) and serum (p = 0.011) and higher serum Cu levels (p = 0.026) were detected when compared to healthy controls. Results of this study show that amendments in Cu and Mo levels might be related to altered kidney and liver function and disrupted hormonal balance in PCOS women. Cu levels positively correlated with leukocyte count. There was a negative correlation of Mo levels with proteinuria and luteinizing hormone levels. Regarding liver function, Mo negatively correlated with urinary bilirubin levels, and there was a positive association with alanine and aspartate aminotransferase, respectively. Dietary supplement consumption and certain diet habits appeared to be important predictors of exposure to Cu (beef consumption) or Mo (cereal and boiled vegetable consumption) and modify Mo and Cu levels in women. Conclusions: Concentrations of the chemical elements Mo and Cu in biological samples of women appear to be related to PCOS and nutrition. To our knowledge, this is a novel finding for Mo. Additional research is needed to provide more insights into the causality of the PCOS relationship with Mo and Cu in humans.

Background: This study examines the responses of 171 dentists to a comprehensive questionnaire to understand the current practice regarding the use and phase-out of dental amalgam. It assesses compliance with EU Regulation 2017/852 and the Minamata Convention, exploring factors associated with material choice, dentists’ awareness of regulations, and the use of amalgam separators. The study also identifies challenges and proposes support mechanisms to facilitate a smoother transition to mercury-free dentistry. Methods: The research was conducted as a cross-sectional study with 171 dentists who collected data on amalgam use, alternative materials, legislation, and separators through a questionnaire. Results: The study revealed regional and sector-specific variations in amalgam use, emphasizing the role of education, financial incentives, and safety standards on professional practices and the environmental impact. Amalgam use varied the most in adult clinics, influenced by clinical needs, patient preferences, and systemic barriers related to reimbursing costs for alternative materials not covered by health insurance until recently. Paediatric clinics demonstrated higher compliance with phase-out guidelines, highlighting the effectiveness of targeted training and policy interventions. Conclusions: The results of this study provide valuable insights for policymakers and other stakeholders to enhance and improve the planning and implementation of measures (primarily regulative) and support mechanisms to mitigate health risks associated with the use of mercury and encourage transition to safer dental practices. Since the level of compliance with regulatory requirements varies across regions, targeted measures, particularly in adult clinics, can improve the transition process. Targeted educational programs and financial incentives are crucial for the successful gradual phase-out of dental amalgam. Limitations: Potential response bias may arise due to voluntary participation and reliance on self-reported data, which could have influenced the comprehensiveness of responses.

The TRIGA Mark II research reactor at the Jo & zcaron;ef Stefan Institute is a key facility in the field of nuclear research, characterized by its versatility and applicability in a wide range of scientific disciplines. This document highlights its operational history, contributions to nuclear safety, education and various scientific applications, including advances in reactor and radiation physics, neutron activation analysis, environmental science and even contributions to the fight against the COVID-19 pandemic. It highlights the reactor's significant role in fostering international collaborations, improving computer modeling techniques for nuclear research, and providing invaluable educational experiences. The great versatility and applicability of the JSI TRIGA reactor is emphasized by its adaptability to various research needs and its ability to enable groundbreaking studies in both fundamental and applied sciences.

Premature ovarian insufficiency (POI) is poorly understood, with causes identified in only 25% of cases. Emerging evidence suggests links between trace elements (TEs) and POI. This study is the first to compare concentrations of manganese (Mn), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) across urine, serum, and whole blood in women with POI compared to healthy controls (HC), aiming to explore their distribution and potential associations with POI. This cross-sectional-case-control study enrolled 81 participants (40 POI patients and 41 healthy controls) at the University Medical Centre Ljubljana, Slovenia. Blood and urine samples were collected to quantify basic biochemical parameters using standard clinical chemistry methods and concentrations of Mn, Cu, Zn, Se, Mo, As, Cd, Hg, and Pb using inductively coupled plasma-mass spectrometry (ICP-MS). Participants also completed questionnaires on socio-demographics, medical history, lifestyle, and nutrition. Data was analyzed using the Mann-Whitney U test, Student's t-tests, Fisher exact test, logistic regression models adjusted on body mass index (BMI), age, hematocrit, and Kendall's tau correlation. Women with POI had significantly higher BMI and red blood cell (RBC) indices, including hemoglobin, hematocrit, and red cell distribution width (RDW), compared to controls. A larger proportion of POI patients resided in rural agricultural areas. Liver and kidney function assessments showed no significant differences between the groups. Adjusted models revealed that POI patients had significantly lower urinary levels of Cu, Zn, Se, Mo, Cd, Hg, and Pb than controls, while whole blood Mn levels were higher. Serum Cu levels were significantly elevated in POI patients, whereas Pb, Cd, and Hg were lower. No significant differences were observed for As. Correlation analysis showed several strong to moderate associations among TEs across biofluids, but only weak correlations were found between TEs and demographic or biochemical factors. This study suggests potential associations between TEs and POI in women. Notably, most TEs (Zn, Se, Cu, Mo, Cd, Hg, Pb) were significantly lower in the urine of the POI group, while Cu, Cd, Hg, and Pb showed significant differences in both urine and serum.

Calibration is crucial in quantitative analysis, ensuring the traceability of standards for an accurate comparison of results. In mercury determinations, a gas calibrator unit containing liquid mercury is used for calibration by injecting headspace volumes via syringe. The Dumarey equation has been used for over 35 years to calculate mercury headspace concentration, aligning closely with saturated vapor pressure equations. However, the 2006 Huber equation yields different values, creating discrepancies. This paper compares calibrations using the Dumarey equations against NIST 3133 certified reference material, with detection by a cold vapor atomic fluorescence spectrophotometer (CV-AFS). The gas standard was injected directly, while HgII in NIST 3133 was reduced to Hg0 and captured on gold traps. Across 10–24 °C, the Hg0 concentration was determined, with uncertainties ranging from 2.9% to 8.4% for a coverage factor of two. No significant differences were found between calibrations using NIST 3133 and the Dumarey equation. These findings provide crucial insights into the traceability and accuracy of mercury calibration methods, ensuring the reliability of measurements used for environmental monitoring and regulatory compliance.

The National Institute for Environmental Studies (NIES) developed the NIES CRM No. 13-a, a new certified reference material for human hair, using scalp hair from Asian females. This CRM represents a significant advancement in support of global mercury exposure assessments and offers unparalleled reliability and scope compared with existing materials. We aimed to provide a comprehensive overview of the preparation, certification, and application of NIES CRM No. 13-a. In total, 806 bottles (3 g each) were produced, with thorough homogenization ensured through sieving and blending. Certified values for total mercury (1.06 ± 0.07 mg/kg), methylmercury (0.858 ± 0.075 mg/kg), and key trace elements (arsenic, cadmium, lead, selenium, and zinc) were determined through extensive collaborative analyses involving 20 laboratories. Additional reference values were provided for calcium, magnesium, sodium, sulfur, antimony, barium, copper, iron, and manganese. Rigorous stability and homogeneity assessments demonstrated the stability of the CRM for over 10 years and consistency across sample units, even for challenging elements such as selenium. The CRM also includes information values of stable mercury isotope ratios, reflecting their growing importance as exposure tracers. This enhancement in accuracy and traceability facilitates accurate mercury and trace element assessments in human hair, enabling improved biomonitoring of mercury exposure, dietary studies, toxicological evaluations, human health risk evaluations, and regulatory compliance.

Methylmercury is a bioaccumulative neurotoxin that poses severe risks to marine ecosystems and human health worldwide. Hydrothermal systems and submarine volcanoes are natural sources of mercury, yet the magnitude of emissions, their transport, and their impact on marine ecosystems remain poorly understood. Quantifying natural mercury fluxes is essential to understanding anthropogenic perturbations and guiding effective reduction strategies. We investigate hydrothermal mercury inputs at the Tonga volcanic arc and their impact on the local ecosystem. Our results show that hydrothermal and volcanic activity in the Tonga Arc increases mercury concentrations in seawater. Comprehensive surveys identified mercury-rich plumes (up to 22.7 pmol L-1) associated with high mercury fluxes (4763 pmol m-2 day-1) reaching productive surface waters, resulting in an estimated total flux of 4.23 t y-1 for the entire Tonga Arc. Despite these significant inputs, mercury concentrations in phytoplankton remain unexpectedly low. We demonstrate that phytoplankton blooms, stimulated by natural iron fertilization from hydrothermal sources, dilute mercury at the cellular level, reducing the impact of hydrothermal mercury. Additionally, we provide a revised global estimate of hydrothermal mercury inputs with a maximum of 120 t y-1, which is considerably lower than atmospheric and riverine inputs to the ocean.

Abstract. The determination of gaseous oxidized mercury (GOM, HgII) in the atmosphere at ultra-trace levels necessitates a preconcentration step. KCl-coated denuders and cation exchange membranes (CEMs) are widely used preconcentration methods for sampling HgII. Sampling losses during preconcentration could result in measurement biases. This study evaluated the performance of denuders and CEMs in retaining HgII, to accurately estimate biases through a precise mass balance approach using 197Hg radiotracer and generation of specific HgII species by non-thermal plasma oxidation of Hg0 in the presence of reactant gases. The results showed that recovery of HgII by thermal decomposition from freshly prepared denuders were approximately 100 %. The retention of HgII on denuders during sampling period was much poorer compared to CEMs. Freshly prepared denuders lost up to 61.5 % of HgII, while reused denuders lost up to 79.7 % after 2 hours of ambient air exposure. CEMs exhibited much lower losses over 72 hours: on average, 16.7 % for HgO, 2.7 % for HgCl2, and 3.8 % for HgBr2. The standard digestion procedure for CEMs by BrCl digestion was found to be incomplete, with a few residual amounts detected on CEMs post-digestion (5.3 % on average). Additionally, the overall mass distribution within the CEM filter pack cartridges revealed that some HgII was retained on their inner Teflon parts. These findings underscore the critical importance of addressing biases in methods adopted for HgII measurements, to improve the accuracy and reliability of atmospheric Hg data, an integral component in evaluating Hg model outputs for Minamata convention effectiveness evaluation.