环境科学与生态学最新文献

Total mercury (THg) was quantified in dorsal muscle from 12 blue sharks (Prionace glauca; six males and six females; 167-230 cm total length) landed at the artisanal fishing port of Ilo, southern Peru, in October 2021. THg was determined by cold-vapour atomic absorption spectrometry at an ISO/IEC 17025-accredited laboratory. Concentrations ranged from 0.021 to 0.330 mg kg^-1 wet weight, with a mean of 0.156 ± 0.102 mg kg^-1. All samples were below the applicable regulatory limits for shark and represented 1.3-20.6% of the Codex Alimentarius maximum level for methylmercury (1.6 mg kg^-1), for which THg may be used as a screening measure. THg increased significantly with total length (Pearson r = 0.768, p = 0.003). Females had higher mean concentrations than males, although the difference was not statistically significant and should be considered preliminary. Dietary exposure was evaluated using fresh-products (40 g day^-1) and total-products (70 g day^-1) screening scenarios derived from Peruvian apparent-consumption statistics. Under the fresh-products scenario, Target Hazard Quotient (THQ) values were 0.98 for general adults and 2.09 for children aged approximately 9-10 years; under the total-products scenario, they increased to 1.71 and 3.65, respectively. Estimated weekly intake remained below the methylmercury Provisional Tolerable Weekly Intake (PTWI) for adults but reached 159.7% for children under the total-products scenario. These findings provide an independent preliminary local reference dataset for P. glauca landed at Ilo. Although measured THg concentrations were low, the conservative exposure scenarios indicated potential concern for children, highlighting the need for larger monitoring datasets, methylmercury speciation, and local shark-consumption surveys.

Per- and polyfluoroalkyl substances (PFAS), particularly perfluorooctane sulfonate (PFOS), persist in humans and have been associated with cardiovascular outcomes, but cardiac-specific molecular responses remain incompletely characterized. We integrated transcriptomic screening, ensemble machine learning, molecular docking and 100-ns molecular dynamics, cross-species cardiac single-cell atlases with virtual knockout, and a time-stratified mouse exposure study (approximately 5 μg/kg/d for 4-8 weeks) to prioritize candidate molecular nodes associated with PFOS-related cardiac remodeling. Robustness analyses supported the stability of the machine-learning prioritization, and MYH6 was repeatedly selected and enriched in cardiomyocytes across human and mouse atlases. Docking and simulation supported a structurally plausible modeled PFOS-MYH6 complex. In exposed mice, Myh6 expression declined over time as septal asymmetry and interstitial fibrosis increased. Batch docking revealed 11 of 26 PFAS with scores at least as favorable as PFOS, indicating compound-level variation in modeled MYH6 compatibility. Together, the data prioritize MYH6 as a candidate molecular node associated with PFOS-related HCM-like remodeling and integrate these multiscale observations into a testable putative AOP-like hypothesis.

Tropospheric ozone (O₃) formation is often limited by NOx, VOCs, or both, necessitating detailed understanding of its spatiotemporal sensitivity for effective control. This study used hourly Geostationary Environment Monitoring Spectrometer (GEMS) data to investigate the diurnal variations of O₃ formation sensitivity over Fujian Province, Southeast China, during the 2024 warm season. GEMS observations reveal pronounced diurnal and spatial heterogeneity in O₃ precursor indicators. Gridded (0.25°) HCHO/NO₂ thresholds for regime transitions were derived from a steady-state O₃-NOx-VOC model with GEOS Composition Forecast (GEOS-CF) simulations. The NOx-Limited transition threshold ( [Formula: see text] ) declines notably from 08:45 to 13:45 LT and is substantially higher in coastal than inland regions. Extreme Gradient Boosting (XGBoost) machine learning with Shapley Additive Explanations (SHAP) analysis indicates that [Formula: see text] is dominantly governed by VOC reactivity (VOCR) across scales. After applying the gridded thresholds, we find that warm season O₃ production across Fujian is predominantly NOx-Limited, with the province-wide fraction rising from ∼71% at 08:45 LT to 92% at 14:45 LT. Inland areas remain NOx-Limited all day, whereas coastal cities display morning VOC-Limited conditions that shrink toward urban cores; many of which stay VOC-Limited during peak photochemistry hours. Thus, in high-emission coastal urban centers, NOx-only controls may be ineffective or counterproductive, requiring prioritized VOC reductions. In contrast, NOx abatement remains a critical priority for inland regions. This work highlights the unique capability of GEMS to resolve diurnal precursor variability and demonstrates that spatially and temporally differentiated control strategies are essential for effective O₃ mitigation in Fujian and similar coastal regions.

Given that temperature and fine particulate matter (PM_2.5) may jointly influence semen quality through overlapping biological pathways, including oxidative stress, inflammation, and endocrine disruption, while epidemiological evidence regarding their interaction remains limited, we conducted this study to evaluate their associations and potential interactions. We applied linear mixed models (LMMs) with natural cubic splines to characterize potential nonlinear associations between temperature and semen quality. To further examine whether these associations differed by PM_2.5 exposure levels, we conducted stratified piecewise regression analyses of temperature separately within the higher and lower PM_2.5 exposure groups across the low- and high-temperature segments. Temperature showed inverted U-shaped associations with semen quality during the 0-90, 0-9, 10-14 day exposure windows. Further stratified piecewise regression analyses suggested a synergistic interaction between high temperature and PM_2.5 and an antagonistic interaction between low temperature and PM_2.5, mainly affecting progressive motility and total motility. Our findings suggest that PM_2.5 may modify the association between temperature exposure and sperm quality, particularly progressive motility and total motility, and that the combined effect of high temperature and PM_2.5 warrants further attention in male reproductive health research and prevention.

Given widespread antibiotic use and residues, this study examined associations of multi-class urinary antibiotic exposure with childhood overweight and obesity (OWOB) risk, identified potential dietary sources, and explored lipidomic signatures and potential indirect effects. We analyzed two cohorts from China: the 4C cohort (Inner Mongolia, 2024; n = 692) for diet-exposure analyses and the CBPEF cohort (Xiamen, 2018/2020; n = 594) for repeated-measures exposure-adiposity and lipidomics analyses. Twenty-four urinary antibiotics across six classes were measured by LC-MS/MS. BMI percentile, OWOB, and untargeted serum lipidomics were assessed, with lipidomics performed in a CBPEF subsample of 73 children. Multi-class antibiotic exposure and co-exposure were common in both cohorts, with >94% of children in the 4C cohort and ≥98% in the CBPEF cohort having at least two detected antibiotics. In the 4C cohort, fish/seafood intake was associated with higher detection of sulfonamides, tetracyclines, and quinolones, with the strongest diet-exposure association observed for seafood intake and sulfonamide detection (OR = 2.17, 95% CI: 1.05-4.48), whereas plant-based intake was inversely associated with total detected antibiotic counts (β = -0.492). In the CBPEF cohort, each additional antibiotic detected was associated with a 0.63-point increase in BMI percentile (95% CI: 0.34-0.92), and each additional human antibiotic detected was associated with 14% higher odds of OWOB (OR = 1.14, 95% CI: 1.04-1.24). Cumulative sulfonamide, quinolone, macrolide, tetracycline, and phenicol counts were positively associated with BMI percentile (β range: 1.15-2.45). Lipidomic analyses identified 102 candidate lipids shared by urinary antibiotic exposure metrics and BMI percentile, with PC1-based indirect-effect signals across multiple antibiotic classes and pathway annotations mainly involving steroid/cholesterol-related metabolism. These findings suggest that contemporary Chinese children and adolescents commonly experience multi-class antibiotic exposure, particularly involving quinolones and macrolides, which may partly reflect dietary and environmental sources and contribute to childhood obesity risk, with lipidomic signatures suggesting involvement of steroid/cholesterol-related metabolism.

The Strait of Malacca is a major global shipping corridor, yet the potential radiological impact of Naturally Occurring Radioactive Materials (NORM) in crude oil spills remains unquantified for this region. This study extends existing static, single-scenario dose modeling of NORM-contaminated oil slicks into a systematic, multi-parameter Monte Carlo framework using the TOPAS code, applying ²²⁶Ra and ²²⁸Ra activity concentrations, oil compositions, and environmental conditions specific to the Strait of Malacca. Absorbed dose rates were evaluated in seawater and to ICRP Reference Animals and Plants (RAPs) for both surface slicks and contaminated seabed sediments, representing short- and long-term exposure phases. Absorbed dose scales linearly with spill thickness but saturates with increasing lateral extent, reflecting water-mediated photon attenuation, and up to 25% of the integrated dose is deposited beyond the visible slick boundary, indicating a measurable peripheral exposure pathway. Despite higher per-decay photon energies in the ²²⁸Ra (thorium series) decay chain, ²²⁶Ra dominates total dose under realistic activity concentrations because of its higher assumed fraction in the radium mixture. Predicted dose rates (~ 10^- 1 µGy/day) remain several orders of magnitude below established radiological benchmarks for marine biota. These findings provide a quantitative framework for interpreting NORM-related exposure in marine oil spills, support the prioritization of chemical over radiological impacts in spill response, and highlight the relevance of sediment-associated pathways for long-term assessment.

Chest radiography is a sensitive method for tuberculosis (TB) detection, and portable X-ray systems offer a practical solution for community-based screening. However, whether the image quality of portable systems is diagnostically comparable to that of mobile and stationary systems remains insufficiently addressed. This study compared image quality and ambient dose equivalent H*(10) per radiographic exposure across one portable, three mobile, and three stationary X-ray systems. Image quality was evaluated using a test object for radiography (TOR) contrast-detail phantom at acrylic thicknesses of 13 cm, 22.5 cm, and 32 cm, and using an anthropomorphic chest phantom assessed by two radiologists and one pulmonologist according to the European guidelines on quality criteria for diagnostic radiographic images. Spatial resolution, low-contrast sensitivity, and high-contrast sensitivity were analysed using AutoPIA and, where automated analysis was not possible, visual scoring with ImageJ (median values from three independent observers). Scattered radiation was quantified as ambient dose equivalent H*(10) per exposure at 1.0 m from the centre of the phantom. Values were measured directly at 1.0 m for the 13 cm and 22.5 cm acrylic thicknesses and the anthropomorphic chest phantom; for the 32 cm thickness, the 1.0 m value was estimated by inverse square law extrapolation from a measurement obtained at 1.5 m. For the TOR phantom, the portable system produced spatial resolution and contrast sensitivity values generally within the range observed for the mobile and stationary systems across the tested thickness conditions. For the anthropomorphic phantom, the portable system achieved the highest median total score (45 out of 45), with all systems meeting the defined threshold for acceptable diagnostic quality (median score of 4 or higher per criterion). H*(10) per exposure from the portable system ranged from 0.12 to 0.97 µSv across acrylic thicknesses and were within the ranges observed for the mobile and stationary systems. These findings support the potential use of the evaluated portable X-ray system for chest imaging and TB screening in community-based settings; however, the scattered-radiation measurements should be interpreted as baseline reference data, and further clinical and workload-based studies are needed to confirm real-world image quality and occupational radiation exposure.