地球科学最新文献

{"title":"Important but Overlooked Reactive Organic Carbon (ROC) Air Pollution From Permafrost Wildfires in Canada","authors":"Xueying Liu,Zejiang Yu,Yifang Ban,Hemraj Bhattarai,Theodore K. Koenig,Lingcao Huang,Enze Zhang,Claire Granier,Guy Brasseur,Zhe Wang,Jimmy C. H. Fung","doi":"10.1029/2026gl124165","DOIUrl":"https://doi.org/10.1029/2026gl124165","url":null,"abstract":"","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"62 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149272002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Riparian freshwater lenses adjacent to curved rivers: morphology and controls","authors":"Hongrong Zong, Huiqiang Wu, Wenyu Xu, Kai Lu, Jiaxin Chen, Chunhui Lu","doi":"10.1016/j.jhydrol.2026.136660","DOIUrl":"https://doi.org/10.1016/j.jhydrol.2026.136660","url":null,"abstract":"Freshwater lenses can persist in saline floodplain aquifers adjacent to gaining rivers, yet existing research has largely examined them in cross section and has not systematically addressed the role of river planform geometry. This study provides the first systematic assessment of how river planform geometry modifies riparian freshwater lens morphology under gaining river conditions. Riverbank traces are represented using sine-generated curves with varying deflection angles. Three-dimensional variable-density groundwater flow and solute transport simulations are then conducted to examine freshwater–saltwater distributions in these idealized planforms. The results show that freshwater lenses extend farther inland near convex banks than near concave banks. Riverbank curvature redirects upper freshwater toward convex sectors, whereas deeper mixed and saline groundwater flows toward concave sectors. This redistribution contributes to the greater lens extent near convex banks. When valley wavelength is fixed, increasing sinuosity enlarges the lens, with freshwater storage increasing by a factor of 7.65 as the deflection angle increases from 0° to 105°. However, when channel length is fixed, freshwater storage initially increases and then declines as sinuosity increases. Stronger saline groundwater discharge compresses the lens toward the river, where its morphology is more constrained by local bank curvature. These findings highlight the need to consider river planform geometry when assessing freshwater storage in saline riparian aquifers, as spatial variability in freshwater availability may otherwise be underestimated.","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"6 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149292455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrological forcing reshapes nitrogen partitioning under microplastic amendment in hyporheic zones","authors":"Shiqi Liu, Zhenhua Yan, Tao Zhang, Xi Chen, Lan Ma, Yuqiong Yang, Ping Lu, Saiyu Yuan, Guanghua Lu","doi":"10.1016/j.jhydrol.2026.136686","DOIUrl":"https://doi.org/10.1016/j.jhydrol.2026.136686","url":null,"abstract":"Microplastics (MPs) are increasingly recognized as potential modifiers of nitrogen (N) cycling in aquatic sediments. Hyporheic zones (HZs), hotspots for riverine N transformation and important sinks for MPs, are exposed to dynamic hydrological forcing. However, how hydrological forcing structures N transformation responses in MP-amended HZs remains poorly understood. Here, we used field-collected sediments to simulate HZs and examined N transformation responses in sediments amended with conventional polyvinyl chloride (PVC) and biodegradable polylactic acid (PLA) MPs under contrasting drying-rewetting alternation (DWA) regimes and hydraulic retention time (HRT) levels. DWA enhanced sediment reoxygenation, weakened dissolved oxygen (DO) stratification, and altered putative nitrification-related taxa, enzyme-associated protein responses, and selected N-cycling functional genes in a polymer-specific manner. In PVC-amended HZs, DWA strengthened the coupling between nitrification-related responses and apparent nitrate reduction, whereas in PLA-amended HZs it promoted oxidative N transformation indicators but reduced apparent nitrate reduction, NO<ce:inf loc=\"post\">2</ce:inf><ce:sup loc=\"post\">−</ce:sup> accumulation, and NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup> accumulation. Longer HRT reduced DO availability and generally increased apparent NO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">−</ce:sup> reduction. In PVC-amended HZs, this was accompanied by greater NO<ce:inf loc=\"post\">2</ce:inf><ce:sup loc=\"post\">−</ce:sup> and NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup> accumulation. In PLA-amended HZs, higher dissolved organic carbon (DOC) availability and sustained low-DO conditions coincided with greater apparent NO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">−</ce:sup> reduction and stronger NO<ce:inf loc=\"post\">2</ce:inf><ce:sup loc=\"post\">−</ce:sup> and NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup> accumulation. Multivariate analyses identified DO-centered associations under DWA and PVC-HRT, whereas DOC-centered associations emerged under PLA-HRT. These findings show that hydrological regime and polymer identity jointly structure N transformation responses in MP-amended HZs, with distinct patterns associated with oxygen availability, carbon availability, and nitrate-derived N partitioning.","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149292452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How Is Overland Flow Sediment Transport Capacity Affected by Biological Crusts?","authors":"Jing Wang,Xiaobing Yu,Yanfen Yang,Yu Liu,Guobin Liu,Zhijian Zhang,Bing Wang,Heng Liu","doi":"10.1029/2026wr044098","DOIUrl":"https://doi.org/10.1029/2026wr044098","url":null,"abstract":"","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"65 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149275000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of peninsular Southeast Asian biomass-burning smoke on chemical apportionment of aerosol light extinction at a high-altitude remote environment in the western North Pacific","authors":"Shantanu Kumar Pani, Chung-Te Lee, Neng-Huei Lin","doi":"10.1016/j.atmosres.2026.109421","DOIUrl":"https://doi.org/10.1016/j.atmosres.2026.109421","url":null,"abstract":"The Lulin Atmospheric Background Station (LABS; 2862 m) sits directly downwind of peninsular Southeast Asia, capturing the fingerprints of regional environmental shifts and serving as a silent witness to the changing chemistry of our atmosphere. A study focusing on the springs of 2014 and 2015 reveals a stark narrative of how human-driven biomass-burning (BB) interacts with climate and air quality. During BB periods, PM<ce:inf loc=\"post\">2.5</ce:inf> concentrations were significantly higher in 2014 (17.2 ± 8.2 μg m<ce:sup loc=\"post\">−3</ce:sup>) and 2015 (21.1 ± 9.8 μg m<ce:sup loc=\"post\">−3</ce:sup>) than during non-biomass-burning (NBB) periods (7.3 ± 3.7 and 4.8 ± 2.4 μg m<ce:sup loc=\"post\">−3</ce:sup>, respectively). PM<ce:inf loc=\"post\">2.5</ce:inf> mass consisted mainly of organic matter (OM; 37–66%) and (NH<ce:inf loc=\"post\">4</ce:inf>)<ce:inf loc=\"post\">2</ce:inf>SO<ce:inf loc=\"post\">4</ce:inf> (19–37%). Diagnostic ratios confirmed the dominance of BB, with K<ce:sup loc=\"post\">+</ce:sup>/OC ratios (0.09–0.10) matching signatures of agricultural waste burning. K<ce:sup loc=\"post\">+</ce:sup>/EC ratios were noticeably higher during BB periods (0.28–0.37) than during NBB periods (&lt;0.20). Aerosol optical properties reflected mass changes: the light extinction coefficient (b<ce:inf loc=\"post\">ext</ce:inf>) increased by a factor of 1.7 during BB days in 2014 (114 ± 56 vs. 68 ± 30 Mm<ce:sup loc=\"post\">−1</ce:sup>) and was 5 times higher in 2015 (130 ± 58 vs. 24 ± 13 Mm<ce:sup loc=\"post\">−1</ce:sup>). Chemical apportionment of b<ce:inf loc=\"post\">ext</ce:inf> using the revised Interagency Monitoring of Protected Visual Environments (IMPROVE) algorithm identified OM as the main contributor to visibility reduction (63–72% and 34–54% during BB and NBB periods, respectively). Although the revised IMPROVE algorithm showed high reliability during BB periods (R<ce:sup loc=\"post\">2</ce:sup> = 0.86–0.91), it involved a complex mix of mineral dust and secondary inorganics. Findings highlight the significant influence of regional BB on PM<ce:inf loc=\"post\">2.5</ce:inf> and visibility at a remote site, while also pointing out the limitations of standard extinction models in low-concentration, multi-source background environments.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"32 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149290713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CO2 leakage mitigation in defective wellbores: From permeability–Pressure diagnosis to MICP grouting","authors":"Hongyu Chen, Yuze Wang","doi":"10.1016/j.enggeo.2026.109177","DOIUrl":"https://doi.org/10.1016/j.enggeo.2026.109177","url":null,"abstract":"Wellbore defects are a major engineering risk for geological carbon storage, creating high-permeability pathways for CO<ce:inf loc=\"post\">2</ce:inf> migration across confining boundaries. Despite growing interest in microbially induced calcium carbonate precipitation (MICP) as a remediation approach, systematic evaluation under varying reservoir permeability and pressure conditions remains lacking. This study develops an axisymmetric coupled multiphase-flow and biogeochemical model to quantify leakage behaviour and assess MICP injection strategies for defective wellbores. Simulation results reveal that leakage is controlled by the interplay between reservoir pressure dissipation and defect transmissivity. In high-permeability reservoirs, each order-of-magnitude reduction in defect permeability produces a corresponding decrease in leakage flux, making targeted sealing the most effective first intervention. In low-permeability reservoirs, pressure accumulation dominates and should be managed prior to sealing; otherwise, substantially greater reductions in defect permeability are required. Among the evaluated MICP strategies, injection from within the defect zone provides superior sealing performance by promoting the formation of a hydraulically effective low-permeability barrier at the defect inlet. Under the present axisymmetric configuration, leakage mitigation is strongly associated with localised permeability reduction along the leakage pathway, allowing nonuniform cementation to achieve comparable mitigation with reduced treatment volume. Under the simulated conditions, all strategies reduce leakage ratios below 0.1%, with defect-zone injection yielding superior performance. The results provide a process-based framework for prioritising sealing versus pressure management under site-specific geological conditions.","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"1 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149290951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoupled ammonia nitrogen and total nitrogen exports under hydroclimatic variability in an alpine headwater catchment of the central Qinghai-Tibet Plateau","authors":"Xueping Wang, Xiaolin Shui, Yujie Zhang, Xiaohong Zhao, Zhoufeng Wang, Bo Hu, Haixia Zhu","doi":"10.1016/j.jhydrol.2026.136695","DOIUrl":"https://doi.org/10.1016/j.jhydrol.2026.136695","url":null,"abstract":"As the “Asian Water Tower” with a fragile alpine ecosystem, nitrogen loading in the Qinghai-Tibet Plateau (QTP) is critical to the water security of the downstream Yangtze River. This study elucidated the spatiotemporal dynamics and potential factors of nitrogen export in the Tongtian River through long-term monitoring (2015–2024) and seasonal sampling, coupled with Optimal Parameters-based Geographical Detector (OPGD) analysis. The results revealed a distinct temporal decoupling between ammonia nitrogen (NH<ce:inf loc=\"post\">3</ce:inf>-N) and total nitrogen (TN). TN concentration and flux exhibited a persistent upward trend (<ce:italic>p</ce:italic> &lt; 0.001) over the decade·NH<ce:inf loc=\"post\">3</ce:inf>-N concentration showed no significant trend (<ce:italic>p</ce:italic> &gt; 0.05), whereas its flux exhibited a significant upward trend (<ce:italic>p</ce:italic> &lt; 0.01), a signal captured only after controlling for intra-annual variability. TN concentrations were highest in the spring campaign (1.71 mg/L), while the NH<ce:inf loc=\"post\">3</ce:inf>-N campaign mean was highest in summer (0.26 mg/L) and close to the autumn and winter means. OPGD identified cropland as the factor with the highest explanatory power for NH<ce:inf loc=\"post\">3</ce:inf>-N concentration (<ce:italic>q</ce:italic> = 0.54) and pH as the primary explanatory factor for TN concentration (<ce:italic>q</ce:italic> = 0.53). Suspended sediment concentration had the highest explanatory power for NH<ce:inf loc=\"post\">3</ce:inf>-N flux (<ce:italic>q</ce:italic> = 0.56), whereas TN flux was predominantly associated with pH and suspended sediment concentration (<ce:italic>q</ce:italic> = 0.74 and 0.71, <ce:italic>p</ce:italic> &lt; 0.001). Interaction analysis further indicated joint associations of land-use, hydro-meteorological, and suspended sediment variables with temporal variability in nitrogen export. The contrasting nitrogen patterns may reflect differences in catchment inputs, hydrological transport, and temperature-dependent transformations. Therefore, management strategies must shift from passive concentration monitoring to actively decoupling anthropogenic practice from peak hydro-sedimentary windows","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"9 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149292437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of Compound Marine Heatwaves and Acidity Extremes in the Southern Ocean","authors":"Joel Wong,&nbsp;Matthias Münnich,&nbsp;Nicolas Gruber","doi":"10.1029/2026GB009430","DOIUrl":"https://doi.org/10.1029/2026GB009430","url":null,"abstract":"<p>Our previous work revealed that between 1980 and 2019, Column-Compound eXtremes (CCX) of Marine Heatwaves (MHW) and Ocean Acidity eXtremes (OAX) increased in frequency and intensity in the Southern Ocean (Wong et al., 2025, https://doi.org/10.1029/2025gb008630), disproportionately affecting the Antarctic zone and its Marine Protected Areas (MPAs). These extremes were identified using a fixed baseline in hindcast simulations with the Regional Ocean Modeling System (ROMS) coupled with the Biological Elemental Cycling (BEC) model. Extremes were classified as CCX when at least 50 m of each extreme was present in the upper 300 m. Here, we identify the driving processes of these CCX, using a detrended baseline to better separate these processes from the trend. We group these detrended CCX into four clusters, according to the locations of MHW and OAX within the water column. Surface CCX are primarily a response of MHW thermodynamically increasing acidity, with increased stratification reducing productivity. Subsurface CCX, particularly the most extreme ones around Antarctica, are mostly caused by the upwelling of warm and acidic Upper Circumpolar Deep Water. The CCX characterized by surface MHW and subsurface OAX tend to be initiated by MHW, which stimulates higher productivity and export, thereby enhancing remineralization at depth. The occurrence of these clusters is modulated interannually by large-scale climate variability that influences Ekman divergence and upper-ocean stratification. Improving our understanding of the links between large-scale climate variability and local CCX processes provides a foundation for improving the predictability of CCX and assessing their potential impact on marine ecosystems, particularly within MPAs.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149259526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluid-inclusion-petrography-guided chlorine isotopes in deeply buried continental halite reveal paleobrine and hydroclimate evolution","authors":"Xintao Wang, Yunqi Ma, Pei Ni, Yuqin Sun, Peng Cheng, Hui Tian, Yong Chen","doi":"10.1016/j.chemgeo.2026.123785","DOIUrl":"https://doi.org/10.1016/j.chemgeo.2026.123785","url":null,"abstract":"Halite δ<ce:sup loc=\"post\">37</ce:sup>Cl is a promising proxy for reconstructing paleobrine and hydroclimate evolution in continental evaporite systems, but its reliability in deeply buried deposits depends on distinguishing primary isotopic signals from diagenetic modification. Here, we integrate fluid-inclusion petrography with targeted Cl isotope analysis of modern halite from the Qarhan Playa and deeply buried Early Eocene bedded halite from the Dongying Depression, China. Paired FI-rich and FI-poor primary crystals from modern halite show absolute δ<ce:sup loc=\"post\">37</ce:sup>Cl differences of 0.01‰–0.54‰ (mean 0.28‰), but no systematic directional offset (mean signed difference = −0.02‰). Together with mass-balance constraints, these results indicate that inclusion-hosted brines exert a limited influence on measured primary-halite δ<ce:sup loc=\"post\">37</ce:sup>Cl without producing a detectable systematic isotopic bias. In contrast, altered crystals from deep-buried halite show larger absolute δ<ce:sup loc=\"post\">37</ce:sup>Cl differences from paired FI-rich primary crystals (0.23‰–2.02‰; mean 0.79‰), with shifts varying in both magnitude and direction. Burial-related closed-system brine–halite re-equilibration may modify the Cl concentration and potentially the δ<ce:sup loc=\"post\">37</ce:sup>Cl composition of inclusion-hosted brines without necessarily resetting bulk whole-crystal δ<ce:sup loc=\"post\">37</ce:sup>Cl, whereas open-system diagenetic fluid–halite interaction can overprint primary isotopic signatures. Petrographically screened FI-rich primary halite from the Dongying Depression preserves coherent δ<ce:sup loc=\"post\">37</ce:sup>Cl trends that, combined with sedimentological evidence, reveal spatially variable brine evolution during the mid- to late Early Eocene Climate Optimum and an overall arid hydroclimate punctuated by short-term dry–wet fluctuations, followed by generally wetter conditions in the late interval. These findings establish petrographic screening as critical for reliable δ<ce:sup loc=\"post\">37</ce:sup>Cl-based reconstruction of paleobrine and hydroclimate evolution in deeply buried continental evaporite systems.","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"14 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149274620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-media review of polycyclic aromatic compounds in the Alberta Oil Sands Region","authors":"Md Noim Imtiazy, Prabin Rokaya","doi":"10.1016/j.earscirev.2026.105748","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105748","url":null,"abstract":"Polycyclic aromatic compounds (PAC) are contaminants of major concern in Alberta's Oil Sands Region (OSR), yet research remains fragmented across environmental media and disciplines. This review synthesizes 107 peer-reviewed studies (2001–2025) to provide the first cross-media synthesis of PAC dynamics in the OSR. Atmospheric PAC concentrations generally fall within ranges reported for rural and semi-rural environments globally, with fugitive dust, wind-blown petroleum coke, and tailings ponds identified as key industrial sources. Atmospheric concentrations and deposition to snowpack and vegetation show consistent exponential distance-decay gradients, with alkylated PAC and dibenzothiophenes dominating near-industrial signatures. In aquatic systems, PAC concentrations are generally low to moderate and infrequently exceed available guidelines, which cover only a few parent PAC. Natural McMurray Formation outcrop erosion and hydrological processes exert strong, sometimes dominant, control over PAC loading in the Athabasca River and its tributaries, complicating source attribution. Nonetheless, lake sediment records document post-development increases in PAC fluxes and shifts toward petrogenic signatures, indicating industrial atmospheric inputs. In biota, PAC can cause sublethal developmental, immunological, and endocrine effects, but population-level impacts remain difficult to disentangle from co-occurring stressors such as nutrient enrichment and climate change. Persistent knowledge gaps include analytical heterogeneity across studies, widespread reliance on diagnostic ratios for source attribution, inadequate guidelines, spatial bias toward the surface-mineable Athabasca OSR, and arbitrarily designated central reference points that oversimplify emission heterogeneity. Advancing OSR PAC science will require standardized analytical frameworks, expanded compound coverage, integrated multi-media monitoring designs, advanced source-attribution tools, comprehensive and validated emissions/release inventories, and meaningful Indigenous community engagement.","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"6 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149274838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}