An emerging persistent organic pollutant, perfluorohexane sulfonic acid (PFHxS), has drawn considerable attention owing to its female reproductive toxicity. PFHxS penetrates the blood-follicle barrier and accumulates in follicular fluid, with a prolonged elimination half-life in humans. Mechanistically, PFHxS impairs oocyte quality through oxidative stress, mitochondrial damage, disruption of hypothalamic-pituitary-gonadal (HPG) axis signaling, meiotic spindle abnormalities, and epigenetic modifications. Animal models demonstrate that PFHxS exposure leads to follicular arrest, reduced ovulation, and intrauterine growth restriction in offspring. Human studies have associated exposure with diminished ovarian reserve, prolonged amenorrhea, and reduced high-quality embryos. Current research highlights a shift from single-compound to mixture effects and transgenerational epigenetic inheritance, yet significant gaps remain regarding chronic low-dose exposure and causal evidence in clinical populations. Future research should focus on realistic exposure models and large-scale prospective cohorts, and the existing evidence should be integrated into regulatory frameworks to safeguard reproductive health.

Organotin compounds, such as tributyltin (TBT), are environmental contaminants known for toxic effects. Subacute exposure to TBT leads to vascular dysfunction associated with increased production of reactive oxygen species (ROS). This study aimed to investigate whether a single exposure to TBT induces endothelial dysfunction. Adult female rats were divided into two groups: control (CT) and TBT-exposed. Vascular reactivity of isolated aortic rings was assessed 24hours after a single oral dose of TBT (500ng/kg). Vasodilator responses to acetylcholine and sodium nitroprusside were not altered by TBT exposure. However, aortic rings from TBT-exposed rats exhibited greater contractile response to phenylephrine and reduced influence of endothelial denudation or L-NAME incubation on vascular reactivity. The impaired nitrergic modulation induced by TBT was prevented by co-incubation with superoxide dismutase plus L-NAME. In vitro DAF-2 assay indicated reduced NO production in the TBT group. TBT-induced vascular hyperreactivity was reversed by incubation with apocynin, TIRON, catalase, allopurinol, losartan, indomethacin, NS-398, SQ-29,548, and SC-19,220. In contrast, the non-selective NOX inhibitor VAS2870 did not modify the response to phenylephrine. Dihydroethidium staining showed increased ROS levels- including superoxide anion and hydrogen peroxide-in aortas from TBT-exposed animals. Scanning electron microscopy revealed endothelial structural damage in the TBT group. Together, these findings indicate that a single dose of TBT (500ng/kg) caused vascular dysfunction, likely resulting from impaired endothelial and nitrergic modulation mediated by increased ROS production derived from xanthine oxidase, activation of the local renin-angiotensin system, and cyclooxygenase pathways in female rats.

Organophosphorus (OP) nerve agent and pesticide exposure pose a threat to both the armed forces and civilians. To support clinical decision-making, erythrocyte acetylcholinesterase and plasma butyrylcholinesterase activity in whole blood can be evaluated. Currently, laboratory diagnosis is time-consuming and not broadly available. Thus, we developed in a proof-of-concept study a lateral flow assay for the rapid, on-site diagnosis of an OP poisoning. The lateral flow assay is based on the colorimetric Ellman reaction and detects total cholinesterase activity in whole blood through a clear color change at the test strip, allowing for visual evaluation. OP poisoning is indicated when no color change occurs on the absorbance pad of the test strip, while normal cholinesterase activity is indicated by a pronounced yellow color change. A parallel visual control strip serves as a reference; its yellow color intensity is calibrated to represent uninhibited cholinesterase activity, helping users interpret the results. Furthermore, the reproducibility and sensitivity of the lateral flow assay were assessed using the persistent organophosphate nerve agent VX and the organophosphate pesticide paraoxon-ethyl. The findings indicated high reproducibility and adequate sensitivity.

The European Food Safety Authority (EFSA) has established a tolerable daily intake (TDI) of 1 mg/kg bw/d for the plasticizer DINCH (Cyclohexane-1,2-dicarboxylic acid diisononyl ester). To characterize the maximum internal doses resulting from a single dosing and to assess species differences relevant for extrapolating rat toxicokinetics to humans, concentration-time profiles of DINCH and its metabolites (specific monoesters: MINCH, OH-MINCH, oxo-MINCH, cx-MINCH; non-specific metabolite: CHDA) were quantified in the blood of male Wistar rats and male human volunteers. Urinary excretion of metabolites was additionally evaluated for humans. Single oral doses of ring-deuterated DINCH were administered (rats: 1 or 40 mg/kg bw; humans: 1 mg/kg bw). In rats, gastrointestinal absorption exhibited saturation, as a 40-fold increase in administered dose resulted in only ∼25-fold increases in Cmax and AUC. Across species, the hierarchy of Cmax in blood was consistent: DINCH > CHDA > cx-MINCH > MINCH > OH-MINCH > oxo-MINCH. Notably, Cmax values for DINCH and MINCH in blood after a 1 mg/kg bw (1.74 µM and 0.10 µM) dose in humans were like those observed in rats following a 40-fold higher dose (4.4 µM and 0.11 µM). Corresponding AUC∞ values showed the same pattern, indicating greater systemic availability of DINCH in humans, although this is partly counter balanced by plasma protein binding. In humans, approximately 50% of MINCH and 70-80% of the other monoester metabolites were glucuronidated, whereas these metabolites remained unconjugated in rats. CHDA was unconjugated in both species. Overall, the data highlight both shared and species-specific features of DINCH metabolism in rats and humans.

Our previous study in vitro has shown that targeting transcription factor Snail might be a strategy for the treatment of silicosis. In this study, we evaluated the feasibility of the strategy in vivo. Here we used CBG transgenic mice which could be used to track and isolate alveolar epithelial type II cells (AT II cells) to confirm that 2.5 mg silica could induce epithelial-mesenchymal transition (EMT) in AT II cells in vivo. Based on the results that 2.5 mg silica induced a rapid elevation of Snail in the lungs of mice and the optimal injection dose and stable expression time of adeno-associated virus (AAV) 9 vectors, we finally decided to inject AAV9-mediated Snail knockdown at 1.0 × 10[11] vg/mouse 1 week before silica instillation to inhibit the levels of Snail increased by silica. The results showed that Snail-shRNA in AAV9 prevented silica-induced EMT in AT II cells in CBG transgenic mice and inhibited EMT and pulmonary fibrosis induced by silica in wild-type mice. Quantitative proteomic analysis combined with dbEMT database mapping further indicated that Snail knockdown suppressed silica-induced EMT and fibrosis through a Fibronectin (FN1)-centered interaction network involving proMMP8 activation and JUN kinase signaling. These findings suggested that Snail could be used as a target for the treatment of pulmonary fibrosis in the future.

Atrazine is a widely used herbicide with non-canonical endocrine-disrupting activity as it does not act as a hormone agonist yet it induces hormone imbalances, represented by induced feminization and heightened aromatase levels. Still, its endocrinological effects remain poorly understood especially in mammalian systems. This study investigated whether atrazine and its two major metabolites (deisopropylatrazine and deethylatrazine) interfere with the conversion of testosterone to dihydrotestosterone in vitro in two cellular models representing the liver and the blood-brain barrier, the latter being herein reported for the first time. Transcriptional activation of the estrogen receptor was assessed, while potential interactions with steroid 5α-reductase isoforms type I and II were evaluated by molecular docking. Testosterone conversion to dihydrotestosterone was measured in Hep-G2 and bEnd.3 cells after acute exposure to atrazine and its two main metabolites at different concentrations (100 nM - 50 μM), along with endpoint cellular metabolic activity. Neither atrazine nor its metabolites activated the estrogen receptor and molecular docking predicted weak interactions of atrazine, deisopropylatrazine and deethylatrazine, with both 5α-reductase isoforms compared with testosterone. Consistent with these predictions, no significant decreases in dihydrotestosterone synthesis were observed in either cell line following treatment, both Hep-G2 and bEnd.3 cells lines retaining the unaffected ability of converting testosterone to its more potent form - dihydrotestosterone. These results indicate that atrazine and its major metabolites do not directly impair testosterone conversion to dihydrotestosterone, and that they are unlikely to disrupt androgen conversion through inhibition of 5α-reductase activity, the main anti-androgenic mechanism known to cause heightened aromatase levels.

The recent use of a Novichok nerve agent for an assassination attempt on Alexei Navalny underlined the importance of identifying effective countermeasures. The immediate decontamination is essential to reduce the penetration of the chemical agent into the systemic circulation. Only limited data are available about the decontamination of Novichok nerve agents on the skin. In this study, we used an in vitro model of human skin to determine the efficacy of decontaminants to remove the agent A-234. The skin was exposed towards A-234 and after 5 min or 30 min the decontamination was initiated by applying different decontamination protocols (Reactive Skin Decontamination Lotion (RSDL), the potassium salt of the acetohydroxamic acid (AHAK), sodium hypochlorite (NaOCl) 2%, soapy water 2% and tap water). Then, the amount of penetrated A-234 was calculated using an acetylcholinesterase inhibition assay. The early decontamination with AHAK was most effective resulting in a complete decontamination, i.e. 0% residual A-234. In contrast, soapy water, tap water, RSDL and NaOCl showed a lower decontamination efficacy and the penetrated amount of A-234 was reduced by 89% (soapy water, tap water), 91% (RSDL) and 95% (NaOCl). The delayed decontamination after 30 min also revealed a complete decontamination of A-234 by using AHAK and an inadequate decontamination using soapy water, tap water, RSDL and NaOCl. In conclusion, the results underline that the decontamination of the Novichok agent A-234 was similar to the V-series nerve agent VX. The relatively new AHAK was a promising decontaminant and deserves further investigation.

Benzene is an important industrial material and environmental pollutant, and even low-level exposure has been associated with hematotoxicity. Therefore, the identification of predisposing factors for hematotoxicity induced by occupational benzene exposure is crucial for managing occupational benzene poisoning. Herein, we recruited 1513 petrochemical workers in southern China, including 847 control workers and 666 workers with hematotoxicity. After randomly dividing the dataset into a training set (75%) and a test set (25%), we employed six machine learning algorithms construct a prediction model. Through recursive feature elimination, 22 feature variables, including age, work years, department, benzene, toluene, xylene, noise, AST/ALT, ALP, GGT, TBIL, DBIL, TC, TG, LDL-C, HDL-C, GLU, SCr, Urea, UA, FEV1/FVC%, and DBP were initially identified. Styrene was included due to its occupational relevance, resulting in 23 input variables for model development. We found the XGBoost algorithm was the optimal model for identifying factors affecting hematotoxicity. SHAP analysis based on the XGBoost model further characterized the contributions of variables at both the overall and individual levels, identifying benzene, noise, work years, age, department, and liver function indicators as important factors while also showing the direction and magnitude of their associations with the predicted risk of hematotoxicity. In vitro experiments also shown that impaired liver function exacerbated 4-benzoquinone (1,4-BQ)-induced cytotoxicity in bone marrow cells and modulated the underlying molecular pathways. Together, liver function-related indicators emerged as important predictors of hematotoxicity risk among benzene-exposed workers. These findings may help inform occupational health surveillance and risk stratification in this population.

2-Ethylhexyl salicylate (EHS) is a UV filter used in sunscreens and personal care products. Mixed-route exposure via both dermal and oral pathways is considered likely, and specific oxidative metabolites of EHS (i.e., 5OH-EHS and 5cx-EPS) in urine have been successfully established as exposure biomarkers for robust human-biomonitoring-based exposure and risk assessments. Previous studies after sunscreen application have reported that EHS itself contributes to the total excretion of specific metabolites. To exclude the possibility of pathway-specific relevant differences in EHS metabolism, in this study, we provide the missing link, i.e., reliable quantitative toxicokinetic data for EHS after oral dose. For this purpose, we re-analyzed samples of a human toxicokinetics study in three volunteers. We found the urinary excretion fraction of EHS after oral uptake to be 0.28% (0.12%-0.51%), similar to 5OH-EHS (on average 0.28%) and 5cx-EPS (0.24%). In the sunscreen application studies, the relative excretion share of EHS was in the same order of magnitude as the oxidative metabolites, about a factor of two higher than 5OH-EHS and 5cx-EPS. Our study provides new quantitative excretion data for EHS itself in urine and confirms the applicability of the oral-route data also for dermal and mixed-route exposure scenarios. It further underlines the validity of the oxidative metabolites as the most sensitive and most robust biomarkers of EHS exposure, which, in contrast to EHS, are not susceptible to external contamination.

Lead (Pb) remains one of the major environmental contaminants and affects multiple systems. Nevertheless, the impact of inhaled Pb exposure on the hemostatic system remains poorly understood. In this research, we evaluated the effects of subchronic lead inhalation on platelet count and activity, D-dimer levels, and clot structure in a murine model. Forty male CD-1 mice were exposed to nebulized particles of lead acetate (5μg/m[3]) or vehicle (saline solution 0.9%) twice weekly for 8 weeks. We measured platelet count using an automated counter, ADP-induced platelet aggregation using optical methods, plasma D-dimer levels by ELISA, and clot ultrastructure by scanning electron microscopy, and analyzed these at different time points (2, 4, 6, and 8 weeks). Femur Pb concentrations were measured at 8 weeks as evidence for Pb absorption and accumulation. Platelet counts were similar between the study groups. However, Pb exposure generated a biphasic platelet response: decreased function in weeks 2 and 4, followed by increased aggregation in weeks 6 and 8. In Pb-exposed mice, plasma D-dimer levels were significantly elevated compared with controls at weeks 6 and 8. Ultrastructural analysis showed a more compact fibrin mesh with thinner fibers and less space between them. These findings suggest subchronic Pb inhalation changes platelet responsiveness and fibrin clot structure, consistent with a prothrombotic phenotype. Since thrombosis, thrombin generation, and fibrinolytic resistance were not directly measured, these results should not be interpreted as proof that Pb caused an in vivo thrombosis event.

Indoor air pollutants that significantly affect human health are often present simultaneously, leading to combined exposure. However, the toxicological effects of combined exposure on the lungs remain unclear. This study aimed to evaluate pulmonary toxicity resulting from combined exposure to dominant airborne microorganisms and particulate matter (PM). C57BL/6 mice were exposed to a combination of microorganisms and PM via intratracheal instillation for two weeks. Certain combinations of PM and microorganisms produced a marked increase in toxicity. The group co-exposed to PM and Bjerkandera adusta(fungi) showed a notable increase in eosinophil infiltration in the lungs compared to the groups treated with each agent alone. Lung histopathological changes suggestive of fibrogenesis was observed in the group co-exposed to PM and Bifidobacterium infantis(bacteria), which was not evident in the single-agent exposure groups. Transcriptomic analysis of lung tissues showed that genes strongly associated with eosinophil recruitment, such as C3 and IL-3, were synergistically upregulated in the PM and Bjerkandera adusta co-exposure groups compared to the single-agent exposure groups. Additionally, extracellular matrix-related genes, including collagen superfamily implicated in fibrosis, also exhibited positive synergistic increases in expression in the PM and Bifidobacterium infantis co-exposure groups. Overall, this study provides critical toxicological evidence that combined exposure to indoor air pollutants, such as PM and microorganisms, can induce some critical positive synergy toxicity, suggesting that the actual health risks may be greater than those previously estimated for each hazard.

4,4'-Methylene diphenyl diisocyanate (MDI) is a reactive diisocyanate used in polyurethane production. Despite potential occupational skin contact, quantitative data on dermal uptake in humans is limited. The dermal absorption and distribution of MDI across human abdominal split‑thickness skin was measured in a flow‑through system according to the OECD test guideline no. 428. [[14]C]MDI was topically applied as a single 10 mg/cm[2] neat dose to the skin (n = 8). Exposure was terminated after 8 hours by skin washing, while receptor sampling continued for 16 hours. The amounts of MDI in the receptor fractions, dermis, epidermis, stratum corneum (20 tape strips) and the skin washing fluids were quantified by liquid scintillation counting. The mean total recovery of radioactivity was 94.82% for precise mass balance calculations. The mean dislodgeable fraction, calculated as the sum of skin washes and donor chamber washing, accounted for 94.52% of the applied dose. The total amount recovered in tape strips plus remaining skin was below 0.30% per skin preparation, with the first two tape strips accounting for 0.22% of the applied dose. The mean absorbed dose in the receptor fluid was 0.0003% of the applied dose. [[14]C]MDI shows negligible dermal absorption into the receptor compartment; radiolabel is largely removable by washing after 8 hours of exposure time with only trace skin‑associated residues, indicating rapid skin immobilization due to reactive isocyanate groups. For pure MDI, these human‑skin data support risk assessments focusing on skin‑mediated hazards such as sensitization rather than systemic toxicity associated with systemic availability.

Melamine (MEL) gained global attention years ago following hospitalizaiton of hundreds of thousands of infants due to contamination of baby formula, which had been adulterated to falsely elevate protein content. This study aimed to investigate the effects of MEL e exposure on heart tissue starting from the weaning period. Eighteen female rats in the weaning period (21 days) were divided into 3 groups. The control group received 0.1 ml of saline orally for 3 weeks. The other two groups received 50 and 75 mg/kg MEL e in 0.1 ml saline for 3 weeks, respectively. On 45th day, the rats were euthanized under anesthesia, and their heart tissue was removed and placed in neutral formalin. Histopathological analysis of hematoxylin & eosin (H&E), Masson's trichrome, periodic acid schiff (PAS), reticulin stained cardiac tissue, anti-connexin 43 (Cx43) and anti-cardiac troponin I (cTnI) positivity were evaluated. The findings showed that 50 mg/kg MEL e increased myocardial damage, congestion, and inflammatory cell infiltration, while exposure to 75 mg/kg MEL e increased myocardial damage, inflammatory cell infiltration, congestion, and fibrosis in the perivascular area, as well as decreasing cTnI and Cx43. In conclusion, MEL exposure from the weaning period or early postnatal period may cause structural and functional impairments in the heart tissue, including histological changes, as well as impairments in cTnI associated with contraction units and Cx43 units responsible for impuls transmission.