Chemosphere最新文献

{"title":"ROS-JAK/STAT-E-cadherin axis underlies cadmium induced premature differentiation of germline stem cells in Drosophila males","authors":"Abik Nandi ,&nbsp;Snigdha Gupta","doi":"10.1016/j.chemosphere.2025.144805","DOIUrl":"10.1016/j.chemosphere.2025.144805","url":null,"abstract":"<div><div>The interaction between stem cells and their niche is essential for sustaining stem cell identity, and in the <em>Drosophila testis</em>, this interaction is maintained by E-cadherin. Our earlier work demonstrated that cadmium (Cd), an environmental toxicant, disrupts germline stem cell (GSC) homeostasis in <em>Drosophila</em> males, although the underlying molecular mechanisms remained unclear. In this study, we aimed to elucidate the mechanism by which Cd alters GSC homeostasis, using <em>Drosophila</em> testis as an <em>in vivo</em> model. Our findings show that Cd induced reactive oxygen species downregulate E-cadherin expression through modulation of JAK/STAT signaling pathway, resulting in disrupted GSC homeostasis, characterized by diminished stem cell pool and premature differentiation. Notably, overexpression of superoxide dismutase in early-stage of germ cells restored JAK/STAT signaling and E-cadherin levels. Additionally, early germ cells targeted E-cadherin overexpression with genetic background of <em>stat92E</em> knockdown showed significant recovery from aberrant GSC homeostasis under Cd exposure. Together, these results are consistent with a Cd mediated effect in which E-cadherin stands as a pivotal factor in maintaining GSC homeostasis. This study highlights the utility of <em>Drosophila</em> as an alternative model to investigate the role of cell adhesion molecules (CAMs) in stem cell regulation under chemical stress and further extended understanding about mechanistic insights mediating Cd toxicity in <em>Drosophila</em>.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144805"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145835455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracking the transformations and by-products of antimicrobials in soil by means of high-resolution mass spectrometry","authors":"I. Vergara-Luis ,&nbsp;J.C. Báez-Millán ,&nbsp;E. Anakabe ,&nbsp;O. Zuloaga ,&nbsp;M. Olivares ,&nbsp;A. Prieto","doi":"10.1016/j.chemosphere.2025.144773","DOIUrl":"10.1016/j.chemosphere.2025.144773","url":null,"abstract":"<div><div>Beyond soil composition, several critical factors—such as organic matter content, soil pH, and the concentration of antimicrobial substances (AMs)—significantly influence both the adsorption and persistence of AMs, as well as the potential development of AM transformation products (TPs) in soil. Although AMs and their TPs contribute to soil environmental pollution, there is still a lack of research on the degradation of AMs and the identification of TPs. In this context, this study investigated the degradation of four AMs from different families—sulfamethoxazole (SMX), oxytetracycline (OTC), enrofloxacin (ENRO), and trimethoprim (TMP)—in a soil:compost mixture (97.2:2.8 w/w). The analysis was carried out at two concentration levels (1 mg kg⁻¹ and 150 mg kg⁻¹) under controlled light and humidity conditions. The results showed a higher degradation rate for SMX, regardless of the initial concentration, and a higher persistence in soil for the fluoroquinolone ENRO. In addition, nineteen potential TPs were identified using a suspect screening analysis approach, many of which, to our knowledge, have not been previously identified in soil:compost samples. The higher degradation rate observed for SMX coincided with the highest recorded abundances of TPs of SMX. Conversely, the highest diversity of identified TPs was observed for TMP. This work also extends the information on the transformation mechanism leading to the detected TPs. However, there is still a large gap regarding the possible activity of the TPs and their influence on resistance propagation. Further research is therefore needed in this area, combining chemical and biological assays.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144773"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the acute toxicity of binary and ternary mixtures of Cu, Zn, As and Se to Daphnia magna: a component-based approach using isobologram analyses and ternary diagrams","authors":"Wijdane Limouni ,&nbsp;Valentin Dupraz ,&nbsp;Patrice Couture ,&nbsp;Carmen Mihaela Neculita ,&nbsp;Vincent Cloutier ,&nbsp;Eric Rosa","doi":"10.1016/j.chemosphere.2025.144791","DOIUrl":"10.1016/j.chemosphere.2025.144791","url":null,"abstract":"<div><div>The acute toxicity of binary and ternary combinations of Cu, Zn, As and Se to <em>Daphnia magna</em> was investigated. The aim was to provide a detailed characterization of the interactive effects of these elements in relation to aquatic toxicity. The binary and ternary combinations were evaluated using isobolograms, the concentration addition (CA) model, the independent action (IA) model, and the Hewlett model. They were also implemented using the MixModel package in R. This approach facilitated the identification of potential synergism, additivity, and antagonism, in addition to the characterization of binary and ternary interactions within a mixture composition space. For the binary combinations, <span><math><mrow><mtext>Cu</mtext><mo>−</mo><mtext>Zn</mtext></mrow></math></span> and <span><math><mrow><mtext>Zn</mtext><mo>−</mo><mtext>Se</mtext></mrow></math></span> had the most robust evidence for synergism with EC₅₀ estimates &lt;1 toxicity unit (TU), as low as 0.27 TU for <span><math><mrow><mtext>Cu</mtext><mo>−</mo><mtext>Zn</mtext></mrow></math></span>, and 0.30 TU for <span><math><mrow><mtext>Zn</mtext><mo>−</mo><mtext>Se</mtext></mrow></math></span>. Combinations of <span><math><mrow><mtext>As</mtext><mo>−</mo><mtext>Cu</mtext></mrow></math></span>, <span><math><mrow><mtext>As</mtext><mo>−</mo><mtext>Se</mtext></mrow></math></span>, <span><math><mrow><mtext>Cu</mtext><mo>−</mo><mtext>Se</mtext></mrow></math></span>, and <span><math><mrow><mtext>As</mtext><mo>−</mo><mtext>Zn</mtext></mrow></math></span> were mostly additive, with EC₅₀ estimates ∼1 TU for all evaluated ratios. In all of the tested ternary combinations, Cu was identified the most toxic component. Emergent effects, which were defined as toxicity responses arising from combinations of toxicity which were not dependent on binary combinations, were observed in some ternary combinations. Synergism was observed in the <span><math><mrow><mtext>As</mtext><mo>−</mo><mtext>Cu</mtext><mo>−</mo><mtext>Se</mtext></mrow></math></span> and <span><math><mrow><mtext>As</mtext><mo>−</mo><mtext>Cu</mtext><mo>−</mo><mtext>Zn</mtext></mrow></math></span> mixtures, suggesting that binary combinations alone are insufficient for predicting interactions involving more than two components. Ternary diagrams also showed potential areas of high toxicity (<span><math><mrow><mtext>TU</mtext><mspace></mspace><mo>&gt;</mo><mspace></mspace><mn>3</mn></mrow></math></span>), mostly in the Cu-dominated mixtures. These observations suggest that the toxicity assessment of trace metals and metalloids commonly found in mining and metallurgical effluents (in this case Cu, Zn, As, and Se) must take into account the effect of mixtures and not rely on substance-by-substance assessments.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144791"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-reactivity hydrated lime prevents de novo dioxin formation in the 200–400 °C flue-gas window via chlorine scavenging and Damköhler-based design","authors":"Yasuro Fuse ,&nbsp;Sho Kanada ,&nbsp;Kako Shinohara ,&nbsp;Xue Chu ,&nbsp;Takashi Kasamatsu ,&nbsp;Takashi Nakai","doi":"10.1016/j.chemosphere.2026.144833","DOIUrl":"10.1016/j.chemosphere.2026.144833","url":null,"abstract":"<div><div>Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the de novo window (∼200–400 °C) remains a barrier to combining strict emission control with efficient waste-to-energy operation. We evaluated high-reactivity hydrated lime (HR-Ca(OH)₂) as a dual-purpose reagent for mechanistic suppression of de novo PCDD/F formation under simulated municipal solid waste incineration flue-gas conditions. A bench-scale laminar-flow reactor was operated with phenol/p-chlorophenol precursors and Cu-bearing fly ash under compositions representative of full-scale stacks. Across five configurations spanning lab- and stack-relevant geometries, positioning HR-Ca(OH)₂ upstream of Cu-active fly-ash phases (\"lime-first\") reproducibly reduced TeCDD formation and total PCDD/F TEQ by up to one order of magnitude. Kinetic behavior was consistent with full-scale observations: conversions of phenol to chlorophenols (∼1.4 %) and <em>p</em>-chlorophenol to TeCDDs (∼5.2 %) matched reported ranges, supporting external validity. A chlorine mass balance showed that when the Ca:Cu mass ratio was maintained at ≥10, gas-phase HCl was effectively scavenged and chlorine availability for de novo chemistry was strongly depleted. A mechanistic design framework based on an effective Damköhler number, Da = keff·τ, was developed; achieving Da ≥3 yielded ≥95 % suppression under all tested conditions. Sensitivity analyses for SO₂, NOx, H₂O and other stack-relevant interferents indicated that these species modify keff and accessibility but do not shift the Ca:Cu or Da thresholds within typical operating ranges. These results provide quantitative criteria (Ca:Cu ≥ 10; Da ≥3) for low-dioxin, high-efficiency operation and support HR-Ca(OH)₂ as a practical route to in-window suppression in waste-to-energy facilities.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"395 ","pages":"Article 144833"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145999688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A national-scale preliminary overview study of poly- and perfluoroalkyl substances (PFAS) occurrence in aquatic environments of England, UK","authors":"R.J. Patel ,&nbsp;D.C. Gooddy ,&nbsp;B. Marchant ,&nbsp;D.J. Lapworth ,&nbsp;A. James ,&nbsp;M. Cook ,&nbsp;K. Darby ,&nbsp;T. Besien","doi":"10.1016/j.chemosphere.2025.144804","DOIUrl":"10.1016/j.chemosphere.2025.144804","url":null,"abstract":"<div><div>Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) are emerging contaminants, where some are known to harm ecological and human health. Due to their widespread use, PFAS have become commonly detected in aquatic environments, which serve both as pathways and as reservoirs for these pollutants. This study provides the first full quantitative national overview of 41 PFAS compounds in English waterbodies (surface water, groundwater, coastal, and estuarine; n = 850), using High-Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry (HPLC-QQQ). Individual PFAS concentrations at 475 sites ranged from 0.0052 to 480 ng/L while ΣPFAS concentrations per site ranged from 0.024 to 2021 ng/L. Monitoring detected the highest concentrations near large distinct urban areas, though PFAS were also present in rural and undeveloped regions, highlighting the importance of detections across different land use. PFOA was one of the most frequently detected PFAS across all waterbodies, consistent with other studies. No clear correlations were found between PFAS physiochemical properties (chain length and functional group) and concentrations, this may be due to the sampling approach focused which focused on an assessment of background concentrations, rather than point-source, pollution. However, shorter chain PFAS compounds dominated detections in surface waters compared to groundwater. Physical properties and PFAS exposure in waterbodies may play a large role in PFAS detections, as higher concentrations were found in surface water relative to groundwater. Future research should explore PFAS trends over time, consider groundwater sampling depths, examine a broader range of land uses, and assess transboundary PFAS transport to better understand PFAS flux in aquatic systems.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144804"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging and legacy pollutants in abyssal sediments of the world’s largest enclosed waterbody","authors":"Peygham Ghaffari ,&nbsp;Bert van Bavel ,&nbsp;Ali Mehdinia ,&nbsp;Madeline Jefroy ,&nbsp;Reza Rahnama ,&nbsp;Davoud Jahedi Vaighan ,&nbsp;Evgeniy Yakushev ,&nbsp;Mehrshad Taheri ,&nbsp;Ali Hamzehpoor ,&nbsp;Parisa Habibi ,&nbsp;Muna Hosseindoost ,&nbsp;Xie Haichao ,&nbsp;Hamid A.K. Lahijani","doi":"10.1016/j.chemosphere.2025.144802","DOIUrl":"10.1016/j.chemosphere.2025.144802","url":null,"abstract":"<div><div>This study provides the first integrated assessment of emerging (microplastics, MPs) and legacy (organochlorine pesticides, OCPs; polychlorinated biphenyls, PCBs; and polycyclic aromatic hydrocarbons, PAHs) contaminants in abyssal sediments (<span><math><mo>&gt;</mo></math></span>700 m) of the southern Caspian Sea. Vertically resolved cores (0–6 cm) were analyzed to determine compound-specific distributions and persistence. MPs were found only in the surface layer (0–2 cm) at 16 items kg⁻¹ dw, composed exclusively of polyethylene (PE) and polyethylene terephthalate (PET) fibers, indicating restricted downward transport. OCPs such as 4,4<span><math><msup><mrow></mrow><mrow><mo>′</mo></mrow></msup></math></span>-DDT and Dieldrin declined sharply with depth, whereas transformation products (4,4<span><math><msup><mrow></mrow><mrow><mo>′</mo></mrow></msup></math></span>-DDE) and recalcitrant compounds persisted. PCBs were confined to surface sediments, while total PAHs (<span><math><mo>∑</mo></math></span>PAHs) increased with depth (49–68 ng g⁻¹), reflecting stronger contributions from natural petrogenic sources associated with pre-industrial conditions. These results show that the southern Caspian abyss functions as a long-term sink for both emerging and legacy contaminants, governed by hydrographic isolation, weak bottom circulation, and sediment focusing. The co-occurrence of MPs and persistent hydrocarbons underscores the role of enclosed basins in global contaminant storage and long-term pollutant fate.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144802"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145770216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling new abilities of actinobacteria: Proficiency in the bioremoval of the emerging contaminant ivermectin","authors":"Victoria Guadalupe González Holc ,&nbsp;María Alejandra Small ,&nbsp;Gonzalo Arnau ,&nbsp;Claudia Susana Benimeli ,&nbsp;Juan Daniel Aparicio ,&nbsp;Marta Alejandra Polti","doi":"10.1016/j.chemosphere.2025.144806","DOIUrl":"10.1016/j.chemosphere.2025.144806","url":null,"abstract":"<div><div>Emerging contaminants are synthetic or natural compounds that remain largely unregulated in the environment but may pose ecological and health risks. Among them is ivermectin, widely used to treat bovine parasitosis and, more recently, human viral infections. Bioremediation using actinobacteria represents a promising strategy for removing such compounds, given their remarkable metabolic versatility and ability to detoxify contaminants. This study aimed to evaluate the ability of actinobacteria to remove ivermectin. A qualitative screening assay was conducted using 12 strains on solid media. Nine of them showed tolerance and were subsequently cultured in liquid medium supplemented with ivermectin (0.1 g L⁻¹), either as the sole carbon source or in combination with glucose, at 30 °C for 7 days under agitation. In parallel, a robust and validated HPLC-based method for ivermectin extraction and quantification was established. The strains showed differential performance when cultured with either ivermectin or ivermectin plus glucose. Notably, five strains showed growth using ivermectin as the sole carbon source. Among them, <em>Streptomyces</em> spp. ER1 and SG1 achieved the highest rates of ivermectin removal in the presence of glucose, reaching 84 % and 61 % elimination, respectively. This study provides the first evidence of <em>Streptomyces</em> strains capable of utilizing IVM as a sole carbon source and achieving high removal rates via co-metabolism, highlighting their unique potential for bioremediation applications.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144806"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145776506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species-specific benefits in bioremediation of oil refinery sludge via large-scale vermicomposting process: a detailed comparison between Eisenia fetida and Eudrilus eugeniae","authors":"Snigdha Nath,&nbsp;Subhasish Das","doi":"10.1016/j.chemosphere.2025.144782","DOIUrl":"10.1016/j.chemosphere.2025.144782","url":null,"abstract":"<div><div>Bioremediation of oil refinery sludge (ORS) with earthworms offers a sustainable prospect in its pollution mitigation, however species-specific detoxification of ORS remains understudied. We conducted a 90-day mesocosm experiment to study the efficacy of two species, <em>Eisenia fetida</em> (EF) and <em>Eudrilus eugeniae</em> (EE), in ORS valorisation. Changes in physicochemical properties, heavy metal speciation (in gut and compost), and carbon fractions of the vermi-treated ORS composts were evaluated. EE yielded a 1.5-fold higher N increment than EF. EE reduced Ni's bioavailable fraction and residual fraction by 55.9 % and 39.4 %, respectively. EE showed an 11 % higher reduction in labile C pool than EF, with 1.95 % increment in its humic acid fraction. The gut bioaccumulation was 20–47 % higher in EE than EF across heavy metals. Moreover, the removal efficiency of heavy metals with EE was 24 % higher than EF. The higher vermiremediation benefit index (VBI) for EE (1.68) compared to EF (1.45) confirmed EE's efficient NPK mineralization and metal detoxification. Principal component analysis attributed earthworm growth, gut accumulation, and metal reduction to EE's higher VBI. Our findings underline the species-specific potential of <em>E. eugeniae</em> over <em>E. fetida</em> in ORS detoxification, while addressing the need to assess the long-term stability of vermiremediated ORS compost for safer agricultural use.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144782"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of population density and industrial activity on PM2.5-Related adverse health outcomes: A study of the Quebec–Ontario corridor in Canada","authors":"Hwashin H. Shin ,&nbsp;Muzeyyen Kabasakal ,&nbsp;James G. Owen ,&nbsp;Anna O. Delic ,&nbsp;Katarina Kunarac ,&nbsp;Stéphane Buteau","doi":"10.1016/j.chemosphere.2025.144796","DOIUrl":"10.1016/j.chemosphere.2025.144796","url":null,"abstract":"<div><div>Air quality tends to deteriorate in densely populated and industrialized regions, increasing the risk of hospitalization and mortality. The Quebec City–Windsor Corridor (hereafter “Corridor”) is a region in Canada characterized by high population density and extensive manufacturing and transportation infrastructure. This study compared PM_2.5-related health outcomes in the Corridor and non-Corridor regions to assess the influence of population density and industrial activity on human health. We analyzed data from 89 census divisions (CDs), representing approximately 80 % of the Canadian population, including 41 CDs within the Corridor (58 % of the population). Daily PM_2.5 concentrations were linked to daily counts of all-cause, circulatory, and respiratory hospitalizations and mortality. A two-stage modeling approach was used: CD-specific risks were estimated using over-dispersed generalized Poisson models, followed by Bayesian hierarchical models to estimate regional (Corridor vs. non-Corridor) and national risks. While all-cause health outcomes showed little regional difference, cause-specific health risks indicated some regional differences varying by cause, season, age, and sex. Compared to the non-Corridor, the Corridor exhibited higher risks (per 10 μg/m³ PM_2.5) for respiratory hospitalization during the cold season for both non-seniors, age 1–65 years, (0.98 %, 95 % CI 0.00–1.90 % versus −0.01 %, −1.36–1.34 %) and seniors, age 66 and over, (0.97 %, 0.08–1.86 % versus −0.60 %, −2.01–0.75 %), and for circulatory mortality during the warm season for seniors (1.86 %, 0.74–2.92 % versus 0.17 %, −1.66–1.92 %) and females (2.74 %, 1.23–4.25 % versus 0.30 %, −2.24–2.78 %). These findings suggest that Corridor residents — especially seniors and females— are subject to greater PM_2.5-related health risks.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144796"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Box-modelling of HOx in Mexico City","authors":"Farah Jeba ,&nbsp;Bernhard Rappenglück ,&nbsp;Tanzina Akther ,&nbsp;Morshad Ahmed ,&nbsp;Armando Retama ,&nbsp;Olivia Rivera-Hernández","doi":"10.1016/j.chemosphere.2025.144813","DOIUrl":"10.1016/j.chemosphere.2025.144813","url":null,"abstract":"<div><div>This study presents an analysis of hydroxyl (OH) and hydroperoxyl (HO₂) radicals collectively referred to as HO_x and their role in atmospheric chemistry within the Mexico City Metropolitan Area (MCMA). HO_x radicals are paramount to the oxidative capacity of the atmosphere driving the formation of secondary pollutants such as ozone (O₃) and secondary organic aerosols (SOA). A 0-D chemical box model (AtChem-2) was employed to simulate in situ production of OH and HO₂ constrained by measurements of volatile organic compounds (VOCs), nitrogen oxides (NO_x), O₃, and other trace gases along with meteorological data collected during the campaign during the dry season. The analysis compares two distinct events: a pre-ozone episode with background conditions and an ozone episode characterized by strong photochemical activity confined to the MCMA. The results indicate significantly higher concentrations of OH and HO₂ of 0.49 ppt and 25.95 ppt respectively during the ozone episode driven by enhanced photolysis of O₃, HONO, and HCHO under clear sky conditions. HONO was identified as the dominant contributor with at least 2/3 to HO_x production averaged over daytime, followed by O₃ and HCHO. CO and VOCs have comparable effects on the loss rate of HO_x while NO_x plays the predominant role in the OH reactivity. The study reveals that elevated radical concentrations during the ozone episode corresponded to stronger and more persistent photochemical reactions by facilitating increased ozone formation of about 163 ppb. These findings underscore the importance of understanding radical production mechanisms in polluted urban environments particularly for the development strategies aimed at mitigating ozone and SOA levels.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":"394 ","pages":"Article 144813"},"PeriodicalIF":8.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}