1.Obesogenic effects of perinatal bisphenol AF exposure on prepubertal male offspring rats
Xi LIU ; Zhengli YANG ; Xueqing CHENG ; Jun YANG ; Jing XU ; Xinyu HONG
Shanghai Journal of Preventive Medicine 2026;38(2):139-145
ObjectiveTo investigate the disruptive effects of perinatal exposure to the environmental endocrine disruptor bisphenol AF (BPAF) on hepatic lipid metabolism in prepubertal (postnatal day 21, PND21) male offspring rats, and to provide scientific evidence for assessing the obesogenic effect of BPAF. MethodsSprague-Dawley (SD) rats aged 8 weeks were used in this study. Pregnant rats were divided into BPAF dose groups (2, 10, 50 mg·kg⁻¹) and a vehicle control group (corn oil), with 6 confirmed pregnant females per group. Gavage administration started from gestational day 0 and continued until the end of lactation. At PND21, one male offspring per litter was randomly selected. Serum concentrations of glucose (GLU), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), leptin (LEP), free fatty acid (FFA), as well as oxidative stress markers superoxide dismutase (SOD) and malondialdehyde (MDA), were measured. Pathological changes in liver and adipose tissues were evaluated, and the expression levels of genes related to hepatic lipid metabolism were measured. ResultsCompared to the vehicle control group, the 50 mg·kg⁻¹ group showed significantly increased serum LEP and MDA levels in male offspring (P<0.05), and significant upregulation of hepatic lipoprotein lipase (Lpl), fatty acid synthetase (Fas), and peroxisome proliferator-activated receptor γ (Pparg) gene expression (P<0.05). The 2 mg·kg⁻¹ group exhibited a significant increase in adipocyte length (P<0.05), while the 50 mg·kg⁻¹ group showed significant increases in both adipocyte area and length (P<0.05). No significant abnormalities were observed in liver histopathological examination. ConclusionPerinatal exposure to 50 mg·kg⁻1 BPAF induced adipocyte hypertrophy, elevated leptin levels, upregulation of lipid synthesis gene expression, and enhanced oxidative stress in prepubertal male offspring, suggesting that BPAF may exert environmental obesogenic effects by disrupting lipid metabolism pathways.
2.MCC950 Targeted Inhibition of TXNIP-NLRP3 Axis-mediated Podocyte Pyroptosis in Diabetic Nephropathy
Hong ZHENG ; Zhong-Cheng MO ; Hang LIU ; Xi-Zhang PAN ; Bing WEI
Progress in Biochemistry and Biophysics 2026;53(2):418-430
Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) globally, representing a major global health burden with limited disease-modifying therapies. Podocyte injury serves as the core pathological hallmark of DN, and conventional treatments targeting metabolic disorders or hemodynamic abnormalities fail to reverse the progressive decline of renal function. Accumulating evidence over the past decade has established that high glucose-induced podocyte pyroptosis—a pro-inflammatory form of programmed cell death—is a key driving force in DN progression. Its core molecular mechanism hinges on the activation of the TXNIP-NLRP3 inflammasome axis. Under sustained hyperglycemic conditions, excessive reactive oxygen species (ROS) are generated via pathways including the polyol pathway, advanced glycation end products (AGEs) accumulation, and mitochondrial dysfunction. Concurrently, methylglyoxal (a glucose metabolite) mediates post-translational modification of thioredoxin-interacting protein (TXNIP). These events collectively trigger the dissociation of TXNIP from thioredoxin (TRX), a redox-regulating protein. The free TXNIP then translocates to the mitochondria, where it binds to The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) and promotes inflammasome assembly. This assembly activates cysteine-aspartic acid protease 1 (caspase-1), which cleaves Gasdermin D (GSDMD) to generate its N-terminal fragment (GSDMD-NT). GSDMD-NT oligomerizes to form membrane pores, leading to podocyte swelling, rupture, and the release of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18). These cytokines amplify local inflammatory responses, induce mesangial cell proliferation, and accelerate extracellular matrix deposition, ultimately exacerbating glomerulosclerosis. MCC950, a highly selective NLRP3 inhibitor, exerts its therapeutic effects through a multi-layered mechanism: it binds to the NACHT domain (NAIP, CIITA, HET-E and TP1 domain) of NLRP3 with nanomolar affinity, forming hydrogen bonds with key residues (Lys-42 and Asp-166) within the ATP-hydrolysis pocket to block ATP hydrolysis, thereby locking NLRP3 in an inactive conformational state. Additionally, MCC950 interferes with the protein-protein interaction between TXNIP and NLRP3 and regulates mitochondrial homeostasis to reduce ROS production. Preclinical studies have demonstrated that MCC950 dose-dependently reduces proteinuria, restores the expression of podocyte-specific markers (nephrin and Wilms tumor 1 protein, WT1), and alleviates podocyte foot process fusion and glomerulosclerosis in both streptozotocin (STZ)-induced type 1 diabetic models (characterized by absolute insulin deficiency) and db/db type 2 diabetic models (driven by insulin resistance). However, discrepancies in therapeutic outcomes exist across different models—some studies report exacerbated renal inflammation and fibrosis in STZ-induced models—which may stem from differences in disease pathogenesis, intervention timing (early vs. mid-stage disease), and dosing duration. Despite its promising preclinical efficacy, MCC950 faces significant translational challenges, including low oral bioavailability, insufficient podocyte targeting, potential hepatotoxicity, and drug-drug interactions with statins (commonly prescribed to diabetic patients for cardiovascular risk management). Furthermore, off-target effects such as the inhibition of carbonic anhydrase 2 have been identified, raising concerns about its safety profile. Nevertheless, its unique mechanism of action—directly blocking podocyte pyroptosis by targeting the TXNIP-NLRP3 axis—endows it with substantial translational value. In the future, strategies to overcome these barriers are expected to advance its clinical application: targeted delivery via nanocarriers (e.g., PLGA-PEG nanoparticles or nephrin antibody-conjugated systems) to enhance renal accumulation and podocyte specificity; precise patient stratification based on biomarkers such as serum IL-18 and renal TXNIP/NLRP3 expression to identify “inflammatory-phenotype” DN patients most likely to benefit; and combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors—whose metabolic benefits synergize with MCC950’s anti-inflammatory effects. These approaches hold great potential to break through clinical translation bottlenecks, offering a novel, precise anti-inflammatory treatment option for DN and addressing an unmet clinical need for therapies targeting the inflammatory underpinnings of the disease.
3.MCC950 Targeted Inhibition of TXNIP-NLRP3 Axis-mediated Podocyte Pyroptosis in Diabetic Nephropathy
Hong ZHENG ; Zhong-Cheng MO ; Hang LIU ; Xi-Zhang PAN ; Bing WEI
Progress in Biochemistry and Biophysics 2026;53(2):418-430
Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) globally, representing a major global health burden with limited disease-modifying therapies. Podocyte injury serves as the core pathological hallmark of DN, and conventional treatments targeting metabolic disorders or hemodynamic abnormalities fail to reverse the progressive decline of renal function. Accumulating evidence over the past decade has established that high glucose-induced podocyte pyroptosis—a pro-inflammatory form of programmed cell death—is a key driving force in DN progression. Its core molecular mechanism hinges on the activation of the TXNIP-NLRP3 inflammasome axis. Under sustained hyperglycemic conditions, excessive reactive oxygen species (ROS) are generated via pathways including the polyol pathway, advanced glycation end products (AGEs) accumulation, and mitochondrial dysfunction. Concurrently, methylglyoxal (a glucose metabolite) mediates post-translational modification of thioredoxin-interacting protein (TXNIP). These events collectively trigger the dissociation of TXNIP from thioredoxin (TRX), a redox-regulating protein. The free TXNIP then translocates to the mitochondria, where it binds to The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) and promotes inflammasome assembly. This assembly activates cysteine-aspartic acid protease 1 (caspase-1), which cleaves Gasdermin D (GSDMD) to generate its N-terminal fragment (GSDMD-NT). GSDMD-NT oligomerizes to form membrane pores, leading to podocyte swelling, rupture, and the release of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18). These cytokines amplify local inflammatory responses, induce mesangial cell proliferation, and accelerate extracellular matrix deposition, ultimately exacerbating glomerulosclerosis. MCC950, a highly selective NLRP3 inhibitor, exerts its therapeutic effects through a multi-layered mechanism: it binds to the NACHT domain (NAIP, CIITA, HET-E and TP1 domain) of NLRP3 with nanomolar affinity, forming hydrogen bonds with key residues (Lys-42 and Asp-166) within the ATP-hydrolysis pocket to block ATP hydrolysis, thereby locking NLRP3 in an inactive conformational state. Additionally, MCC950 interferes with the protein-protein interaction between TXNIP and NLRP3 and regulates mitochondrial homeostasis to reduce ROS production. Preclinical studies have demonstrated that MCC950 dose-dependently reduces proteinuria, restores the expression of podocyte-specific markers (nephrin and Wilms tumor 1 protein, WT1), and alleviates podocyte foot process fusion and glomerulosclerosis in both streptozotocin (STZ)-induced type 1 diabetic models (characterized by absolute insulin deficiency) and db/db type 2 diabetic models (driven by insulin resistance). However, discrepancies in therapeutic outcomes exist across different models—some studies report exacerbated renal inflammation and fibrosis in STZ-induced models—which may stem from differences in disease pathogenesis, intervention timing (early vs. mid-stage disease), and dosing duration. Despite its promising preclinical efficacy, MCC950 faces significant translational challenges, including low oral bioavailability, insufficient podocyte targeting, potential hepatotoxicity, and drug-drug interactions with statins (commonly prescribed to diabetic patients for cardiovascular risk management). Furthermore, off-target effects such as the inhibition of carbonic anhydrase 2 have been identified, raising concerns about its safety profile. Nevertheless, its unique mechanism of action—directly blocking podocyte pyroptosis by targeting the TXNIP-NLRP3 axis—endows it with substantial translational value. In the future, strategies to overcome these barriers are expected to advance its clinical application: targeted delivery via nanocarriers (e.g., PLGA-PEG nanoparticles or nephrin antibody-conjugated systems) to enhance renal accumulation and podocyte specificity; precise patient stratification based on biomarkers such as serum IL-18 and renal TXNIP/NLRP3 expression to identify “inflammatory-phenotype” DN patients most likely to benefit; and combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors—whose metabolic benefits synergize with MCC950’s anti-inflammatory effects. These approaches hold great potential to break through clinical translation bottlenecks, offering a novel, precise anti-inflammatory treatment option for DN and addressing an unmet clinical need for therapies targeting the inflammatory underpinnings of the disease.
4.Role of Innate Trained Immunity in Diseases
Chuang CHENG ; Yue-Qing WANG ; Xiao-Qin MU ; Xi ZHENG ; Jing HE ; Jun WANG ; Chao TAN ; Xiao-Wen LIU ; Li-Li ZOU
Progress in Biochemistry and Biophysics 2025;52(1):119-132
The innate immune system can be boosted in response to subsequent triggers by pre-exposure to microbes or microbial products, known as “trained immunity”. Compared to classical immune memory, innate trained immunity has several different features. Firstly, the molecules involved in trained immunity differ from those involved in classical immune memory. Innate trained immunity mainly involves innate immune cells (e.g., myeloid immune cells, natural killer cells, innate lymphoid cells) and their effector molecules (e.g., pattern recognition receptor (PRR), various cytokines), as well as some kinds of non-immune cells (e.g., microglial cells). Secondly, the increased responsiveness to secondary stimuli during innate trained immunity is not specific to a particular pathogen, but influences epigenetic reprogramming in the cell through signaling pathways, leading to the sustained changes in genes transcriptional process, which ultimately affects cellular physiology without permanent genetic changes (e.g., mutations or recombination). Finally, innate trained immunity relies on an altered functional state of innate immune cells that could persist for weeks to months after initial stimulus removal. An appropriate inducer could induce trained immunity in innate lymphocytes, such as exogenous stimulants (including vaccines) and endogenous stimulants, which was firstly discovered in bone marrow derived immune cells. However, mature bone marrow derived immune cells are short-lived cells, that may not be able to transmit memory phenotypes to their offspring and provide long-term protection. Therefore, trained immunity is more likely to be relied on long-lived cells, such as epithelial stem cells, mesenchymal stromal cells and non-immune cells such as fibroblasts. Epigenetic reprogramming is one of the key molecular mechanisms that induces trained immunity, including DNA modifications, non-coding RNAs, histone modifications and chromatin remodeling. In addition to epigenetic reprogramming, different cellular metabolic pathways are involved in the regulation of innate trained immunity, including aerobic glycolysis, glutamine catabolism, cholesterol metabolism and fatty acid synthesis, through a series of intracellular cascade responses triggered by the recognition of PRR specific ligands. In the view of evolutionary, trained immunity is beneficial in enhancing protection against secondary infections with an induction in the evolutionary protective process against infections. Therefore, innate trained immunity plays an important role in therapy against diseases such as tumors and infections, which has signature therapeutic effects in these diseases. In organ transplantation, trained immunity has been associated with acute rejection, which prolongs the survival of allografts. However, trained immunity is not always protective but pathological in some cases, and dysregulated trained immunity contributes to the development of inflammatory and autoimmune diseases. Trained immunity provides a novel form of immune memory, but when inappropriately activated, may lead to an attack on tissues, causing autoinflammation. In autoimmune diseases such as rheumatoid arthritis and atherosclerosis, trained immunity may lead to enhance inflammation and tissue lesion in diseased regions. In Alzheimer’s disease and Parkinson’s disease, trained immunity may lead to over-activation of microglial cells, triggering neuroinflammation even nerve injury. This paper summarizes the basis and mechanisms of innate trained immunity, including the different cell types involved, the impacts on diseases and the effects as a therapeutic strategy to provide novel ideas for different diseases.
5.Correlation between driver gene mutation and environmental exposure factors in patients with non-small cell lung cancer in Xi'an City
Yang HU ; Qianrong WANG ; Mengxue WANG ; Na CHENG ; Meijuan WU ; Xianna WU ; Juanhua SUN
Journal of Public Health and Preventive Medicine 2025;36(1):114-117
Objective To understand the driver gene mutation status in patients with non-small cell lung cancer (NSCLC) in Xi'an City, and to analyze the association with environmental exposure factors. Methods A total of 305 NSCLC patients admitted to the First Affiliated Hospital of the Air Force Medical University from January 2019 to December 2023 were included. The driver gene mutation status was observed, and the relationship with environmental exposure factors was analyzed. Results The driver gene mutation rate of 305 patients was 46.89%, with EGFR gene mutation accounting for the highest proportion, and 4 cases of gene co-mutations were detected. There was a difference in gender among patients with different single drive gene mutations (P<0.05), and the proportion of EGFR in women was significantly higher (P<0.05). Univariate analysis showed that there were statistical differences in family history, smoking history, long-term cooking history, and fried smoked food intake between patients with driver gene mutation and patients without driver gene mutation (P<0.05). Logistic regression analysis suggested that long-term cooking history (OR=2.392), and fried smoked food intake (OR=2.849) were the environmental exposure factors affecting EGFR gene mutation (P<0.05), and smoking history (OR=1.377) was an environmental exposure factor of KRAS gene mutation (P<0.05). Conclusion EGFR gene mutation accounts for the highest proportion of NSCLC patients in Xi'an City, and is mainly female. Long-term cooking history, and fried smoked food intake are related to EGFR gene mutation. There is a certain association between smoking history and KRAS gene mutation.
6.Introduction of the main addition and revision of the Chinese Pharmacopoeia 2025 Edition(Volume Ⅱ)
ZHOU Yi ; WANG Zhijun ; YUE Zhihua ; CHENG Qilei ; YUE Ruiqi ; YANG Xi ; GUO Wei ; MA Shuangcheng
Drug Standards of China 2025;26(1):023-027
The Pharmacopeia of the People’s Republic of China 2025 Edition (referred to as the Chinese Pharmacopoeia 2025 Edition, ChP 2025) will be promulgated and implemented. This article introduces the process of development of ChP 2025 Edition (Volume Ⅱ), including the selection, the revision of general notices,the addition and revision of drug monographs, etc., and provides some analysis and examples to illustrate,which can facilitate the readers to understand and implement the ChP 2025 Edition (Volume Ⅱ).
7.Clinical value of intraoperative ultrasound in etiological diagnosis and prognostic evaluation of acute encephalocele in patients with severe traumatic brain injury
Journal of Apoplexy and Nervous Diseases 2025;42(11):1008-1011
Objective To apply bedside ultrasound for real-time monitoring of intracranial conditions in patients with severe traumatic brain injury experiencing acute encephalocele during large craniotomy, and to investigate the clinical value of intraoperative bedside ultrasound in the diagnosis and prognostic evaluation of acute encephalocele. Methods A retrospective analysis was performed for 32 adult patients with severe traumatic brain injury, and according to whether intraoperative ultrasound was performed, they were divided into ultrasound group with 17 patients and CT group with 15 patients. The two groups were compared in terms of time of operation, accuracy, mortality rate, and postoperative Glasgow Outcome Scale (GOS) score. The chi-square test was used for comparison of categorical data between groups, and the independent samples t-test was used for comparison of continuous data between groups. Results Both ultrasound and CT could provide an accurate basis for diagnosis, with no significant difference in diagnostic accuracy; however, compared with the CT group, the ultrasound group had significantly shorter time of operation and diagnostic time. Based on GOS score and grading results at 6 months after surgery, the patients undergoing ultrasound examination had a significantly better prognosis than those undergoing CT examination. Conclusion Intraoperative ultrasound for patients with severe traumatic brain injury enables rapid and accurate identification of etiology, facilitates dynamic intracranial monitoring, and shortens the time for rescue, showing an important clinical significance in improving prognosis and reducing mortality rate. Therefore, it holds promise for clinical application.
8.Novel CD19 Fast-CAR-T cells vs. CD19 conventional CAR-T cells for the treatment of relapsed/refractory CD19-positive B-cell acute lymphoblastic leukemia.
Xu TAN ; Jishi WANG ; Shangjun CHEN ; Li LIU ; Yuhua LI ; Sanfang TU ; Hai YI ; Jian ZHOU ; Sanbin WANG ; Ligen LIU ; Jian GE ; Yongxian HU ; Xiaoqi WANG ; Lu WANG ; Guo CHEN ; Han YAO ; Cheng ZHANG ; Xi ZHANG
Chinese Medical Journal 2025;138(19):2491-2497
BACKGROUND:
Treatment with chimeric antigen receptor-T (CAR-T) cells has shown promising effectiveness in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), although the process of preparing for this therapy usually takes a long time. We have recently created CD19 Fast-CAR-T (F-CAR-T) cells, which can be produced within a single day. The objective of this study was to evaluate and contrast the effectiveness and safety of CD19 F-CAR-T cells with those of CD19 conventional CAR-T cells in the management of R/R B-ALL.
METHODS:
A multicenter, retrospective analysis of the clinical data of 44 patients with R/R B-ALL was conducted. Overall, 23 patients were administered with innovative CD19 F-CAR-T cells (F-CAR-T group), whereas 21 patients were given CD19 conventional CAR-T cells (C-CAR-T group). We compared the rates of complete remission (CR), minimal residual disease (MRD)-negative CR, leukemia-free survival (LFS), overall survival (OS), and the incidence of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) between the two groups.
RESULTS:
Compared with the C-CAR-T group, the F-CAR-T group had significantly higher CR and MRD-negative rates (95.7% and 91.3%, respectively; 71.4% and 66.7%, respectively; P = 0.036 and P = 0.044). No significant differences were observed in the 1-year or 2-year LFS or OS rates between the two groups: the 1-year and 2-year LFS for the F-CAR-T group vs.C-CAR-T group were 47.8% and 43.5% vs. 38.1% and 23.8% (P = 0.384 and P = 0.216), while the 1-year and 2-year OS rates were 65.2% and 56.5% vs. 52.4% and 47.6% (P = 0.395 and P = 0.540). Additionally, among CR patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) following CAR-T-cell therapy, there were no significant differences in the 1-year or 2-year LFS or OS rates: 57.1% and 50.0% vs. 47.8% and 34.8% (P = 0.506 and P = 0.356), 64.3% and 57.1% vs. 65.2% and 56.5% (P = 0.985 and P = 0.883), respectively. The incidence of CRS was greater in the F-CAR-T group (91.3%) than in the C-CAR-T group (66.7%) (P = 0.044). The incidence of ICANS was also greater in the F-CAR-T group (30.4%) than in the C-CAR-T group (9.5%) (P = 0.085), but no treatment-related deaths occurred in the two groups.
CONCLUSION
Compared with C-CAR-T-cell therapy, F-CAR-T-cell therapy has a superior remission rate but also leads to a tolerably increased incidence of CRS/ICANS. Further research is needed to explore the function of allo-HSCT as an intermediary therapy after CAR-T-cell therapy.
9.Advances in the role of protein post-translational modifications in circadian rhythm regulation.
Zi-Di ZHAO ; Qi-Miao HU ; Zi-Yi YANG ; Peng-Cheng SUN ; Bo-Wen JING ; Rong-Xi MAN ; Yuan XU ; Ru-Yu YAN ; Si-Yao QU ; Jian-Fei PEI
Acta Physiologica Sinica 2025;77(4):605-626
The circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.
Protein Processing, Post-Translational/physiology*
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Circadian Rhythm/physiology*
;
Humans
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Animals
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CLOCK Proteins/physiology*
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Circadian Clocks/physiology*
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Phosphorylation
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Acetylation
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Ubiquitination
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Sumoylation
10.Pollution characteristics and health risk analysis of 16 polycyclic aromatic hydrocarbons in atmospheric PM2.5 in two districts of Xi'an City in 2020 - 2022
Yongbing CHENG ; Sicen LIU ; Zhichao LIU ; Zhaowei MENG
Journal of Public Health and Preventive Medicine 2025;36(5):23-27
Objective To analyze the pollution characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 in Yanta District and Lianhu District of Xi'an City, and assess their health risks to exposed populations through inhalation pathways. Methods From 2020 to 2022, monitoring sites were set up in Yanta District and Lianhu District of Xi'an City, and PM2.5 samples were collected regularly every month. The mass concentrations of PAHs were determined. The analysis and evaluation were carried out according to different years, regions, and seasons. The sources of PAHs in the atmosphere were identified by calculating characteristic ratios. Health risk assessments through inhalation routes were conducted for certain polycyclic aromatic hydrocarbons and their total carcinogenic equivalent concentrations. Results The average mass concentrations of PAHs in Yanta District and Lianhu District were 6.38 ng/m3 and 6.06 ng/m3, respectively, with no statistically significant difference (P>0.05). Except for fluoranthene, there was no statistically significant difference in other PAHs between regions (P>0.05). Except for acenaphthylene and anthracene, the concentrations of other PAHs showed a decreasing trend year by year (P<0.05). The total mass concentration of PAHs in both urban areas showed a trend of winter>spring>autumn>summer (P<0.05), and all categories of PAHs showed the highest levels in winter and the lowest levels in summer (P<0.05). The proportion of 5-ring PAHs was the highest in summer, while the proportion of 4-ring PAHs was the highest in winter. The main sources of atmospheric PAHs in the two districts were a mixture of coal combustion, motor vehicle emissions, and biomass burning. The HQ values of benzo[a]pyrene and TEQs in both districts were less than 1. The carcinogenic risk through inhalation pathways for TEQs was 1.15×10-6, exceeding the acceptable level (1×10-6). Conclusion The pollution of PAHs in Yanta District and Lianhu District of Xi'an City continues to decrease, with seasonal differences. The main sources are mixed sources of coal combustion, motor vehicle emissions, and biomass burning, and overall PAHs pose a potential carcinogenic risk to residents.


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