1. Non-linear hair-to-blood mercury partitioning in a chronically exposed Amazonian populationLucas Cassulatti dos Santos, Carlos José Sousa Passos, Milena Horvat, Fernando Barbosa, 2026, izvirni znanstveni članek Povzetek: 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.
Ključne besede: hair-to-blood ratio, methylmercury, blood samples, mercury detection, human biomonitoring
Objavljeno v DiRROS: 04.08.2026; Ogledov: 87; Prenosov: 105
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2. Method development and production of an ambient-stable blood certified reference material for total mercury, methylmercury, and trace elementsKoichi Haraguchi, Mineshi Sakamoto, Hiromitsu Nagasaka, Milena Horvat, Ermira Begu, Polona Klemenčič, Adna Alilović Osolin, Masaaki Nakamura, 2026, izvirni znanstveni članek Povzetek: 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.
Ključne besede: passive monitoring, methylmercury, blood samples, mercury detection, human biomonitoring, trace elements
Objavljeno v DiRROS: 04.05.2026; Ogledov: 340; Prenosov: 315
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3. Decrease in cellular nanovesicles concentration in blood of athletes more than 15 hours after marathonZala Jeras, Mitja Drab, Damjana Drobne, Apolonija Bedina Zavec, Mojca Benčina, Barbara Drašler, Matej Hočevar, Judita Lea Krek, Ljubiša Pađen, Manca Pajnič, Neža Repar, Boštjan Šimunič, Roman Štukelj, Veronika Kralj-Iglič, 2021, izvirni znanstveni članek Povzetek: Introduction: Cellular nanovesicles (CNVs), that are shed from cells, have been recognized as promising indicators of health status. We analyzed the effect of long-distance running on concentration of CNVs, along with some standard blood parameters, in 27 athletes two days before and > 15 hours after physical effort. Methods: CNVs were isolated by repetitive centrifugation and washing of samples, and assessed by flow cytometry. Cholinesterase (ChE) and glutathione S-transferase (GST) activity were measured spectrophotometrically. Interleukin 6 (IL-6) and tumor necrosis factor-% (TNF-%) concentrations were measured using enzyme-linked immunosorbent assay (ELISA). C-reactive protein (CRP) was measured with immunoturbidimetric determination and lipidogram parameters were measured by enzymatic colorimetric assay. Flow cytometry was used for blood cell count and mean platelet volume (MPV) measurement. Results: More than 15 hours after physical effort a decrease was found in CNVs% concentration in isolates from blood (46%; p< 0.05), in ChE activity in whole blood (47%; p< 0.001), in plasma (34%; p< 0.01), and in erythrocyte suspension (54%; p< 0.001), as well as in GST activity in erythrocyte suspension (16%; p< 0.01) and in IL-6 concentration in plasma (63%; p< 0.05). We found no change in GST activity in plasma and in TNF-% concentration in plasma. Correlations (> 0.8; p< 0.001) between CNVs% concentration and ChE activity, and GST activity, respectively, in erythrocyte suspension were found. Conclusion: We found that > 15 hours post-physical effort, CNVs% concentration was below the initial value, concomitant with other measured parameters: ChE and GST activity as well as IL-6 concentration, indicating a favorable effect of physical effort on health status. CNVs% concentration and ChE activity in isolates from peripheral blood proved to have potential as indicators of the response of the human body to inflammation after physical effort. Physical activity should be considered as an important factor in preparation of subjects for blood sampling in procedures focusing on CNV-containing diagnostic and therapeutic compounds.
Ključne besede: membrane vesiculation, physical effort, blood samples, inflammation process, cellular nanovesicles, marathon
Objavljeno v DiRROS: 25.01.2021; Ogledov: 2749; Prenosov: 6697
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