Environmental Monitoring and Assessment最新文献

{"title":"From source to distribution channel: A baseline study of microplastic occurrence in drinking water in Ogun State, Nigeria","authors":"Oluwatosin Sarah Shokunbi,&nbsp;Favour Makanju,&nbsp;Joshua Nneoma,&nbsp;Olutayo Sunday Shokunbi","doi":"10.1007/s10661-025-13929-3","DOIUrl":"10.1007/s10661-025-13929-3","url":null,"abstract":"<div><p>Microplastics (MPs) are emerging contaminants known to have contaminated not only surface and groundwater but also drinking water treatment plants (DWTPs) and tap water. Little is known about the occurrence of MPs in DWTPs in Africa, particularly in developing countries like Nigeria. To address this knowledge gap, this study investigated the prevalence and estimated daily intake of MPs in raw water, DWTPs, and tap water in a semi-urban area in Ogun State, Nigeria. Using Rose Bengal staining and optical microscopy, MPs in water samples were identified and characterised using standard methods. The abundances of MPs were 16.13 ± 3.83 particles/L in raw water, 10.74 ± 3.76 particles/L in treated water, and 12.43 ± 3.92 particles/L in tap water. Most of the MPs found in the water samples were classified as fibres, followed by fragments, with a size of &lt; 1 mm. This study showed that the drinking water treatment plant reduced microplastics from raw water by 40%, however, there was an increase in the abundance of MPs in tap water. Residents estimated daily consumption of MPs from tap water varied between 0.31 and 0.44 particles for adults and between 1.2 and 1.69 particles for children. This study addresses a critical gap in understanding microplastic pollution in the water distribution systems and DWTPs. The results also indicated that MPs were not effectively removed, requiring a more sophisticated treatment method to lower human exposure to MPs through drinking water from DWTPs.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Menstrual wastes: a Sri Lankan perspective on quantities, characteristics, and issues","authors":"Ranil Kavindra Asela Kularatne","doi":"10.1007/s10661-025-13663-w","DOIUrl":"10.1007/s10661-025-13663-w","url":null,"abstract":"<div><p>The importance of good menstruation hygiene management (MHM) practices has gained considerable attention in Sri Lanka, but least attention is given to menstrual wastes regarding the types, quantities, characteristics, disposal practices, and potential environmental impacts due to haphazard disposal. An understanding of the types, quantities, and characteristics of menstrual wastes is crucial to formulate and implement safer collection and environmentally acceptable disposal strategies. Therefore, this paper provides a preliminary viewpoint regarding menstrual wastes generated in Sri Lanka with an overview on source separation (SS), disposal methods, and the legal requirements regarding disposal. Commercially available single-use sanitary pads (100% in Colombo capital city; 17–91% in other regions) and reusable cotton cloths (3–83% in other regions, except in Colombo—0%) are the widely used menstrual hygiene products (MHPs). SS is very low, and overall disposal practices are environmentally unfriendly (e.g., 8–84% flushing into toilets). Pad quantities generated from one menstruator/month are 288.4 g (259.6 g plastic), 360.5 g (324.5 g plastic), and 432.6 g (389.3 g plastic) (from a 5 mL blood-soaked 5 g pad); 436.8 g (393.1 g plastic), 546 g (491.4 g plastic), and 655.2 g (589.7 g plastic) (from a 10 mL blood-soaked 5 g pad); and 568.4 g (511.6 g plastic), 710.5 g (639.5 g plastic), and 852.6 g (767.3 g plastic) (from a 5 mL blood-soaked 15 g pad), and cloths/menstruator/month are 199.4 g, 249.2 g, and 299 g (from a 5 g material) at changing frequencies of 4, 5, and 6 times/day, respectively. Nevertheless, cloth waste quantities that get disposed for any given year are substantially less (due to reuse) compared with sanitary pad wastes. Soiled MHPs are not categorized as infectious wastes or household hazardous wastes in Sri Lanka. Legislative changes with planning of proper SS, collection, and disposal and the use of cotton cloths and/or other environmentally friendly MHPs are suggested.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Ecological response of green spaces to land use change in the Mu Us Desert-Loess Plateau transition zone, China, since the twenty-first century","authors":"Xuegang Gong,&nbsp;Yunzhi Zhang,&nbsp;Jing Ren,&nbsp;Yahui Chen,&nbsp;Keifeng Wang,&nbsp;Runliang He","doi":"10.1007/s10661-025-13906-w","DOIUrl":"10.1007/s10661-025-13906-w","url":null,"abstract":"<div><p>The Mu Us Desert-Loess Plateau transition zone in China, a fragile ecosystem prone to desertification, has undergone substantial ecological restoration since the early twenty-first century. This study utilized land use/cover data from 2000 to 2023 to assess the ecological response of green spaces to these efforts. A comprehensive set of ecological indices—including the green ecosystem index (GEI), equivalent ecological quality (EEQ) index, and green ecological contribution (GEC) rate—was used to quantify changes in green space extent and ecosystem quality. The study results showed a 5.83% increase in green space area, corresponding to an addition of 1979.7 km², along with a notable rise in the GEI across 20.18% of the region, reflecting improved ecosystem function and resilience. The conversion of barren into productive green spaces has mitigated land degradation and supported ecological recovery. The EEQ of regional green spaces improved by 1.16%, and the GEC from land use changes was 1.15%. However, challenges remain, including the degradation of 3114.5 km² of high-quality green spaces and the encroachment of 428.2 km² by non-green land uses. Ongoing monitoring, targeted interventions, and adaptive management strategies are essential for further improving land greening and ecological quality. This study provides valuable insights for sustainable land management and ecological restoration in similar fragile environments.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Microclimate determines the diversity patterns, biomass, and water storage capacity of bryophytes in the alpine ecosystem: a case study in Kashmir Himalaya","authors":"Ramya Ranjan Paul,&nbsp;Soumit Kumar Behera,&nbsp;Krishna Kumar Rawat,&nbsp;Sonik Anto,&nbsp;Vinay Sahu,&nbsp;C. P. Singh,&nbsp;Anzar Ahmad Khuroo","doi":"10.1007/s10661-025-13844-7","DOIUrl":"10.1007/s10661-025-13844-7","url":null,"abstract":"<div><p>The majority of studies on alpine vegetation have focused on higher plants, while relatively little is known about how lower plants, such as bryophytes, respond to microclimate in the alpine ecosystem. Microclimate critically influences the distribution and growth of bryophytes in alpine ecosystems, and therefore, understanding the functional role of microclimate on bryophyte’s physiological adaptation is critical for understanding the climate change response. To fill this knowledge gap, the present study investigated the patterns of species richness, biomass accumulation, and water storage capacity in bryophytes in alpine ecosystems of the Kashmir Himalaya. We conducted stratified systematic field sampling of bryophytes in two major alpine vegetation zones: open meadow above the timberline (AT) and under forest canopy cover below the timberline (BT) in Kashmir Himalaya, along with measurement of five microclimate variables: photosynthetically active radiation (PAR, µmol m⁻² s⁻¹), air temperature (AT, °C), soil temperature (ST, °C), ambient CO₂ concentration (μmol mol⁻¹), and absolute humidity (AH, mmol mol⁻¹). We found a total of 30 bryophyte species, including 3 liverworts and 27 mosses in the two zones with 10 species common. AT zone with greater species richness and more homogenous distribution of bryophytes exhibited higher biomass. Canonical correspondence analysis (CCA) identified PAR and air temperature (AT) as key microclimatic drivers influencing community structure, biomass accumulation, and water storage capacity in above the timberline, while humidity (AH) emerged as the primary factor shaping bryophyte dynamics in below the timberline. This study provides an insight into the ecological dynamics of bryophyte communities and relationships among microclimates with community structure, biomass, and water storage capacity of bryophytes in alpine ecosystems and highlights the need for continuous long-term monitoring to unravel these complex interactions.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 first- time study of cyclic volatile methylsiloxanes in wastewater, sludge, lagoon water, sediments and fishes from Africa","authors":"Oluwatoyin Tirenioluwa Fatunsin,&nbsp;Idayat Kikelomo Akinwale,&nbsp;Omobonike Azeezat Akinsanmi,&nbsp;Aderonke Olubukola Oyeyiola,&nbsp;Kehinde Ololade Olayinka","doi":"10.1007/s10661-025-13819-8","DOIUrl":"10.1007/s10661-025-13819-8","url":null,"abstract":"<div><p>Cosmetic and personal care products are used throughout the world in large quantities. Siloxanes are commonly used in the formulation of these products. The use of these products releases siloxane into the environment. This study quantifies for the first time in Africa specifically in Lagos Nigeria, the amount of two cyclicvolatile methylated siloxane (cVMS) compounds namely octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in wastewater and sludge from industries, water, sediments and fishes from the Lagoon. The samples obtained were extracted and analyses were performed using gas chromatography-mass spectrometry (GC–MS). Results showed higher concentrations of D5 compared with D4 across all sample types. Using the estimated daily intake (EDI) and hazard quotient (HQ) to assess the health risks showed minimal risk to adults and children consuming fish from the lagoon. However, biota-sediment accumulation factor (BSAF) and bioaccumulation factor (BAF) exceeded their benchmark values of 1.7 and 5000 respectively for most of the fishes at all the sites showing bioaccumulation potential at these sites for D4 and D5. This study underscores the need for sustainable practices to mitigate cVMS contamination in Nigeria’s aquatic systems.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"How monitoring crops and drought, combined with climate projections, enhances food security: Insights from the Northwestern regions of Bangladesh","authors":"Tahmid Anam Chowdhury,&nbsp;Zia Ahmed,&nbsp;Md. Aminul Haque Laskor,&nbsp;Abdul Kadir,&nbsp;Fei Zhang","doi":"10.1007/s10661-025-13907-9","DOIUrl":"10.1007/s10661-025-13907-9","url":null,"abstract":"<div><p>Crop and drought monitoring are vital for sustainable agriculture, as they ensure optimal crop growth, identify stress factors, and enhance productivity, all of which contribute to food security. However, climate projections are equally important as they provide future adaptation scenarios for agriculture. This study aims to project climatic scenarios for northern Bangladesh, assess agricultural and meteorological drought, and estimate crop yield using remote sensing and field data. Our simulated data from 21 CMIP6 models (ensemble mean) under SSP2-4.5 scenarios reveal that maximum temperatures will rise in northwestern regions such as Nawabganj, Rajshahi, Naogaon, Dinajpur, and Joypurhat. By 2050 and 2060, the areas affected by rising mean temperatures are expected to expand into other districts. Additionally, projected rainfall is expected to increase in northern districts, particularly after 2040. Drought assessments using the TOTRAM model reveal a water deficit in many areas in 2022, with milder conditions in 2023. Applying SPEI (Hargreaves-Zamani method) from 1984 to 2024, Sirajganj faced moderately dry conditions (14.38%), while Dinajpur had near-normal conditions (63.33%). Our crop yield model, incorporating Leaf Area Index (LAI), NDVI, SAVI, and field data, demonstrates successful yield estimation, with a significant correlation between predicted and observed yields. The multiple linear regression model achieved a 0.82 goodness-of-fit value, indicating effective yield estimation. We emphasize that timely, accurate information dissemination and monitoring are often more effective in preventing agricultural losses than structural developments. This study encourages decision-makers to integrate geospatial technologies and share critical information with farmers to strengthen food security.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Measurement and daily consumption of microplastics in drinking water from a Small Island Developing State—Fiji: from freshwater to groundwater sources","authors":"Roselyn Lata,&nbsp;Timaima Waqainabete,&nbsp;Steven Aru,&nbsp;David Rohindra","doi":"10.1007/s10661-025-13877-y","DOIUrl":"10.1007/s10661-025-13877-y","url":null,"abstract":"<div><p>The occurrence of microplastics (MPs) in drinking water has emerged as a significant source of this contaminant, posing an increased risk to human health. These MPs are now of extreme concern, especially on the possible harmful effects it may have on human health. This study is the first baseline MPs data in drinking water from Fiji. Raw, treated, tap, rain, ground, and bottled water were investigated for the presence of MPs and the ingestion rate by the different age groups. The analytical procedure was validated by determining recovery rates and analyses of blanks. The detection limit of the MPs was 10 µm, while fibers and particles ≥ 100 µm were analyzed on 100% of the filter area. The abundance of MPs in drinking water was source-dependent. Percentage removal of MPs from water treatment plants was 45–67%, resulting in the presence of 0.10 ± 0.03 to 2.90 ± 0.57 MPs L⁻¹ in tap water. The presence of MPs in bottled, rain, and groundwater was in the range of 0 to 2.20 ± 0.41 MPs L⁻¹. Fiber MPs predominated in all water sources except for bottled water. Main types of polymer identified were polyethylene, polypropylene, and poly(ethylene terephthalate). Estimated daily intake of MPs in tap water by children and adults were 0.0031–0.1813 and 0.0021–0.0829 MPs/kg bw/day, respectively. Information from this work in combination with information from the health sector will help to fully understand microplastic impact on human health and the actions that are required to mitigate it.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Single-quad gas chromatography estimation of a few selected pesticides as residues in spices of the National Capital Region of Delhi","authors":"Okram Zenita Devi,&nbsp;Sudeep Mishra,&nbsp;Samsul Alam,&nbsp;L. K. Thakur","doi":"10.1007/s10661-025-13895-w","DOIUrl":"10.1007/s10661-025-13895-w","url":null,"abstract":"<div><p>In India, spices play a vital role not only in enhancing the taste and flavor of food but also in offering medicinal properties that help reduce the risk of chronic diseases. However, the extensive and non-judicious use of pesticides in agricultural practices results in the presence of their metabolites in food commodities (fruits, vegetables, spices, cereals) and soil, leading to environmental contamination. Organochlorine (OC) and Synthetic Pyrethroid (SP) pesticides are commonly used for pest control but pose environmental and health risks. These compounds are known for their high toxicity, slow degradation, and bioaccumulation. The present study assessed pesticide residue (OC and SP) levels in 21 spice samples, representing eight condiments—cumin, coriander, chili, fenugreek, black pepper, mustard, ajwain, and dry ginger powder—collected from Delhi-NCR markets, using Gas Chromatography-Mass Spectrometry (GC–MS) and the QuEChERS method. Lambda-cyhalothrin (0.056–0.088 mg/kg), pendimethalin (0.059 mg/kg), γ-HCH (0.089 mg/kg), fenpropathrin (0.062 mg/kg), and hexaconazole (0.050 mg/kg) were detected in some samples. Specifically, cumin was contaminated with lambda-cyhalothrin and hexaconazole, coriander with cyfluthrin, fenugreek with lambda-cyhalothrin, mustard with pendimethalin, and ajwain with γ-HCH, hexaconazole, and lambda-cyhalothrin. Chili, black pepper, and ginger were free from residues. Average recoveries were 75–90% for ten organochlorine pesticides and 72–85% for seven synthetic pyrethroids, and the RSD% was below 5%. All detected residues were below the maximum residue limits set by FSSAI.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 performance of random forest, support vector machine, gradient tree boost, and CART for improved crop-type monitoring using greenest pixel composite in Google Earth Engine","authors":"Chirasmayee Savitha,&nbsp;Reshma Talari","doi":"10.1007/s10661-025-13880-3","DOIUrl":"10.1007/s10661-025-13880-3","url":null,"abstract":"<div><p>The development of machine learning algorithms, along with high-resolution satellite datasets, aids in improved agriculture monitoring and mapping. Nevertheless, the use of high-resolution optical satellite datasets is usually constrained by clouds and shadows, which do not capture complete crop phenology, thus limiting map accuracy. Moreover, the identification of a suitable classification algorithm is essential, as the performance of each machine learning algorithm depends on input datasets, hyperparameter tuning, training, and testing samples, among other factors. To overcome the limitation of clouds and shadow in optical data, this study employs Sentinel-2 greenest pixel composite to generate a nearly accurate crop-type map for an agricultural watershed in Tadepalligudem, India. To identify a suitable machine learning model, the study also evaluates and compares the performance of four machine learning algorithms: gradient tree boost, classification and regression tree, support vector machine, and random forest (RF). Crop-type maps are generated for two cropping seasons, Kharif and Rabi, in Google Earth Engine (GEE), a robust cloud computing platform. Further, to train and test these algorithms, ground truth data is collected and divided in the ratio of 70:30, for training and testing, respectively. The results of the study demonstrated the ability of the greenest pixel composite method to identify and map crop types in small watersheds even during the Kharif season. Further, among the four machine learning algorithms employed, RF is shown to outperform other classification algorithms in both Kharif and Rabi seasons, with an average overall accuracy of 93.21% and a kappa coefficient of 0.89. Furthermore, the study showcases the potential of the cloud computing platform GEE in enhancing automatic agricultural monitoring through satellite datasets while requiring minimal computational storage and processing.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Concurrent measurements of indoor and outdoor airborne bacteria in university classrooms at a tropical megacity: concentration and bacterial composition","authors":"Dang Diep Yen Nga,&nbsp;Vuong Hong Nhung,&nbsp;Nguyen Thanh Tam,&nbsp;Hieu Tran-Van,&nbsp;To Thi Hien","doi":"10.1007/s10661-025-13885-y","DOIUrl":"10.1007/s10661-025-13885-y","url":null,"abstract":"<div><p>Airborne microbial concentrations in educational buildings are a growing concern due to their impact on student health and learning. This study determined atmospheric bacterial concentrations and composition in indoor and outdoor environments at a university in Ho Chi Minh City, Vietnam. Samples were collected from schoolyards, mechanically and naturally ventilated classrooms, during student presence and absence, March to December 2023. Plate Count Agar was used for bacterial concentration, while 16S rRNA sequencing determined bacterial composition. Indoor concentrations of cultured bacteria ranged 158–541 CFU/m³ , generally lower than outdoor levels 174–718 CFU/m³. Concentrations were higher in occupied rooms than vacant ones and lower indoors compared to outdoors. Most indoor samples were below standards such as the European Commission, WHO and Vietnam (less than 500–1000 CFU/m³). Temperature and relative humidity showed a positive and negative correlation with bacterial concentration (r = 0.348 and -0.628, respectively). Sequencing revealed 37 phyla, 1115 genera, and 1183 species, with Actinobacteriota (32.4%), Proteobacteria (30.6%), and Firmicutes (24.1%) dominating. Alpha diversity showed no significant difference between mechanically (10.36) and naturally ventilated (10.87) rooms. Our findings indicate that human activity may contribute to an increase in bacterial concentrations, whereas mechanical ventilation appears to mitigate this trend. Mechanical ventilation was effective in controlling bacterial concentrations; however, it did not result in significant changes to the bacterial community composition compared to natural ventilation. The findings in this study could contribute to the increasing awareness of the need to maintain optimal air quality in university classrooms, both in the region and nationwide.</p></div>","PeriodicalId":544,"journal":{"name":"Environmental Monitoring and Assessment","volume":"197 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}