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Maternal APOE [epsilon]2 as a possible risk factor for elevated prenatal Pb levels
Neža Palir, Anja Stajnko, Darja Mazej, Alenka France Štiglic, Janja Snoj Tratnik, Agneta Annika Runkel, Janja Marc, Milena Horvat, Ingrid Falnoga, 2024, original scientific article

Abstract: Lead (Pb) is a global contaminant associated with multiple adverse health effects. Humans are especially vulnerable during critical developmental stages. During pregnancy, exposure to Pb can occur through diet and release from maternal bones. Apolipoprotein E gene (APOE) variants (ɛ2, ɛ3, ɛ4 alleles) may influence sex steroid hormones, bone metabolism, and Pb kinetics. We examined the interplay among maternal APOE (mAPOE) genotypes, fetal sex, parity, and Pb in maternal and cord blood (mB-Pb, CB-Pb) using linear regression models. Our study involved 817 pregnant women and 772 newborns with measured adequate levels of zinc and selenium. We compared carriers of the ε2 and ε4 alleles to those with the ε3/ε3 genotype. The geometric means (range) of mB-Pb and CB-Pb were 11.1 (3.58–87.6) and 9.31 (1.82–47.0) ng/g, respectively. In cases with female fetuses, the maternal mAPOE ε2 allele was associated with higher, while the mAPOE ε4 allele was associated with lower mB-Pb and CB-Pb levels. Nulliparity increased the strength of the observed associations. These findings highlight the significance of mAPOE genetics, fetal sex, and parity in prenatal Pb kinetics. Notably, the maternal ε2 allele may increase the risk of Pb exposure.
Keywords: cord blood, maternal APOE ε2 allele, bone turnover, fetal sex, parity
Published in DiRROS: 05.06.2026; Views: 230; Downloads: 222
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3.
Associations between APOE genotypes, urine 8-isoprostane and blood trace elements in middle-aged mothers (CROME study)
Alenka France Štiglic, Anja Stajnko, Alenka Sešek-Briški, Janja Snoj Tratnik, Darja Mazej, Aleš Jerin, Milan Skitek, Milena Horvat, Janja Marc, Ingrid Falnoga, 2024, original scientific article

Abstract: Background. There is almost no data on the combined associations between apolipoprotein E gene (APOE) genotypes, trace elements (TEs), and lipid peroxidation in vivo. The aim of our study was to evaluate the association between APOE genotypes and TE levels in blood (B-TEs) and erythrocytes (E-TEs), and 8-isoprostane in urine (U-8-isoprostane) in women with low exposure to potentially toxic TEs and with adequate supply of essential TEs. Methods. B-TEs, E-TEs and U-8-isoprostane were determined in 172 healthy women of childbearing age (30.1–51.4 years) using ICP-MS and ELISA competitive assay, respectively. All women were divided into three APOE genotype groups according to the presence of the ɛ4 allele, ɛ2 allele or ɛ3 homozygotic allele. The associations between B-TEs, E-TE, U-8-isoprostane, and the APOE genotype groups were estimated by multiple variable linear regression models with relevant explanatory variables (e.g., age, BMI, and seafood). Results. All TE and U-8-isoprostane levels were inside the reference ranges for the healthy population. In the multiple variable linear regression models, our results showed that urine 8-isoprostane levels increased by up to 43.3% in the APOE4 group compared to the APOE3 group and a negligible negative modifying effect for essential TEs. However, the APOE genotype groups were associated also with some TEs. A clear positive association was found between the APOE2 and APOE4 groups (vs. APOE3) with B-molybdenum. Conclusions. Our study suggests that the APOE4 genotype played an important role in 8-isoprostane variability in a population with an adequate supply of essential and with low exposure to potentially toxic TEs. Adequate copper, zinc and selenium status seemed to be protective against, while the levels of nonessential TEs were probably too low to play a decisive role in 8-isoprostane formation. The observed impact of the APOE2 and APOE4 groups on increased B-molybdenum opens a new research topic.
Keywords: apolipoprotein E, polymorphisms, trace elements, multiple variable linear regression models
Published in DiRROS: 05.06.2026; Views: 215; Downloads: 303
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4.
Association of trace elements with polycystic ovary syndrome in women - a case-control study
Tinkara Srnovršnik, Bojana Pinter, Milena Horvat, Janja Snoj Tratnik, Ingrid Falnoga, Darja Mazej, Ivan Verdenik, Irma Virant-Klun, 2025, original scientific article

Abstract: 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.
Keywords: essential elements, non-essential elements, polycystic ovary syndrome, endocrine disruptors, hepatic damage, trace elements
Published in DiRROS: 16.04.2026; Views: 230; Downloads: 177
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5.
The Exposure and Health Examination Survey mother-child(ren) cohort profile : applying the exposome to the comprehension of child’s health and development joining singletons and twins data
Mohamed-Yassir Errahmani, Sara Maio, Sandra Baldacci, Neža Palir, Darja Mazej, Janja Snoj Tratnik, Ingrid Falnoga, Milena Horvat, Isabella Annesi-Maesano, 2025, original scientific article

Abstract: he Exposure and Health Examination Survey (EXHES) cohort aims to elucidate the impact of environmental exposures (the external exposome) and their biological markers (the internal exposome) on childhood health conditions, asthma and allergies, obesity, and cognitive development in particular. Utilizing singletons and twins helped differentiate environmental effects from genetic influences due to the shared genetic background in twins. The EXHES cohort includes 2356 mother-child pairs across 10 European countries, comprising 1945 singletons and 411 twins, with data collected during the crucial first 1000 days of life. Data were gathered through epidemiological questionnaires and biomarkers, including blood, urine, hair, and breast milk from mothers, and cord blood, placenta, and cord tissues from children. Findings confirm that twin pregnancies are linked with increased risks of pregnancy complications, preterm birth, cesarean delivery, low birthweight, maternal health problems during pregnancy and a lower risk of macrosomia. Moreover, mothers of twins were more likely to have asthma, while higher maternal education was associated with a lower likelihood of twin births. The EXHES cohort provides a robust framework to be adopted in other studies for comparing singletons and twins to better understand how the exposome affects early child development and health outcomes. This approach offers new insights into the interplay between environmental and biological factors in shaping long-term health.
Keywords: environmental exposure, biomarkers
Published in DiRROS: 18.02.2026; Views: 471; Downloads: 301
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6.
Human biomonitoring in support of the Minamata Convention : a case of phasing out dental amalgam
Vanja Usenik, Adna Alilović Osolin, Janja Snoj Tratnik, Marta Jagodic Hudobivnik, Darja Mazej, David Kocman, Davor Kontić, Milena Horvat, 2026, original scientific article

Abstract: 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%) and the average number of dental amalgam fillings in children. Multilevel mixed-effects models showed a consistent temporal decline in U-Hg that persisted after adjustment for demographic and environmental covariates. In contrast, the inclusion of the amalgam number substantially attenuated the time trend, indicating that reduced amalgam use likely contributed to the observed decrease. As amalgam prevalence fell, other sources of exposure, such as fish consumption, became relatively more prominent predictors of U-Hg, while children living in historically Hg-contaminated areas showed persistently higher levels. Although Slovenia had already phased down dental amalgam in children before ratifying the Minamata Convention, these long-term biomonitoring data illustrate how changes in exposure sources are reflected in internal Hg levels. The study demonstrates the value of repeated national HBM programmes for identifying dominant exposure pathways, investigating their evolution over time, and providing evidence relevant to effectiveness-evaluation frameworks under Article 22 of the Minamata Convention.
Keywords: concentrations in blood
Published in DiRROS: 10.02.2026; Views: 610; Downloads: 256
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7.
Quantification of phthalate and DINCH metabolites in human urine and maternal breast milk : assessing maternal body burden and infant exposure
Agneta Annika Runkel, Žan Rekar, Neja Kosirnik, Darja Mazej, Milena Horvat, Janja Snoj Tratnik, Tina Kosjek, 2026, original scientific article

Abstract: 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 Keywords: phthalate metabolites, DINCH, human biomonitoring
Published in DiRROS: 14.01.2026; Views: 436; Downloads: 280
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8.
Urban Cycling Lab : a ǂcitizen science protocol for assessing and reducing exposure to environmental stressors among bike commuters
Maria Alejandra Rubio, Rok Novak, Janja Snoj Tratnik, Davor Kontić, Gregor Bučar, David Kocman, 2025, original scientific article

Abstract: Bike commuters are regularly exposed to environmental stressors that impact their health and well-being. The Urban Cycling Lab in Ljubljana, developed within an Urban Living Lab and citizen science framework, engaged stakeholders in assessing exposure to particulate matter and noise, and in co-creating strategies to reduce it. This citizen science intervention combined sensor-enhanced ICT tools with behaviour change theory to assess both environmental and behavioural aspects of exposure. Exposure assessment included low-cost personal sensors as well as chemical analysis in biological samples to evaluate environmental exposure, while biochemical analysis of biological samples aimed to evaluate potential biological effects of exposure. Participants collected data using portable sensors and accessed real-time exposure comparisons via the Route Exposure Comparator web app. Biological samples (peripheral blood and spot urine) were collected from each participant at the end of data collection period. Data on sociodemographic characteristics, commuting habits, and environmental health literacy were collected via questionnaires. Ethnographic methods captured participants’ perceptions, route choices, and the intervention’s influence on commuting behaviour. This paper presents the methodology used to implement this intervention and provides a transferable model for participatory environmental exposure assessment. 1. Designed and implemented a citizen science intervention to assess cyclists’ exposure to air pollution and noise using sensor-enhanced ICT tools. 2. Promoted environmentally informed route choices through behaviour change strategies and digital feedback. 3. Applied survey and ethnographic methods to explore commuting behaviours and intervention impact.
Keywords: personal sensors, environmental exposure assessment
Published in DiRROS: 03.12.2025; Views: 896; Downloads: 292
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9.
Nontargeted urinary profiling strategy for endocrine-disrupting chemicals in women with ovarian malignancies
Helena Plešnik, Žan Rekar, Stefanela Stevanović, Irma Virant-Klun, Senka Imamović-Kumalić, Mateja Sladič, Darja Mazej, Janja Snoj Tratnik, Milena Horvat, Tina Kosjek, 2025, original scientific article

Abstract: Endocrine-disrupting chemicals (EDCs), includingknown and unknown parent compounds, their metabolites, andtransformation products, are pervasive in daily life, posingincreasing risks to human health and the environment. Thisstudy employed a high-resolution mass spectrometry-basednontargeted screening approach, integrating polar (HILIC) andreversed-phase separations to expand the chemical space coverageand, supported by open-science tools and resources, evaluatedurinary chemical profiles to assess internal EDC exposure. Among106 annotated biomarkers of exposure, six exhibited significantlyhigher normalized intensities in patients with ovarian malignanciescompared to healthy controls (p < 0.05). This suggests theirgreater exposure to phthalates (diethylhexyl phthalate and diethylphthalate), 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 ofnontargeted urinary profiling for chemical exposure assessment. By providing new insights into EDCs burden and its pathologicalimplications, this work contributes to advancing next-generation chemical risk assessment within the European Partnership for theAssessment of Risks from Chemicals initiative and supports the development of preventive strategies to mitigate environmentalcancer risks
Keywords: ovarian cancer, biomarkers, exposure, nontargeted screening, high-resolution mass spectrometry, analytical coverage, reversed-phase, HILIC
Published in DiRROS: 02.12.2025; Views: 740; Downloads: 432
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10.
Associations of essential and non-essential trace elements’ levels in the blood, serum, and urine in women with premature ovarian insufficiency
Tina Kek, Ksenija Geršak, Nataša Karas Kuželički, Dominika Celar Šturm, Darja Mazej, Janja Snoj Tratnik, Ingrid Falnoga, Milena Horvat, Irma Virant-Klun, 2025, original scientific article

Abstract: 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.
Keywords: premature ovarian insufciency, essential, non-essential trace elements, biofuids, reproductive health
Published in DiRROS: 12.11.2025; Views: 637; Downloads: 364
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