{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T08:28:20Z","timestamp":1787041700178,"version":"build-2736575974"},"reference-count":33,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T00:00:00Z","timestamp":1786492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"CMU Presidential Scholarship, Master\u2019s Degree Program in Health Sciences Research, School of Health Sciences Research, Chiang Mai University, Thailand","award":["8393(25)\/922"],"award-info":[{"award-number":["8393(25)\/922"]}]},{"DOI":"10.13039\/501100025469","name":"Research Institute for Health Sciences, Chiang Mai University","doi-asserted-by":"crossref","award":["035\/2568"],"award-info":[{"award-number":["035\/2568"]}],"id":[{"id":"10.13039\/501100025469","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Ambient fine particulate matter (PM2.5) is associated with oxidative stress, metabolic dysregulation, and cardiometabolic disease. However, systemic metabolic responses to contrasting real-world ambient air pollution exposure environments remain poorly characterized. In this cross-sectional study, untargeted proton nuclear magnetic resonance (1H-NMR)-based urinary metabolomics was used to investigate metabolic signatures associated with contrasting ambient air pollution exposure environments in Thailand. Adults residing in Chiang Mai (high-exposure region; n = 51) and Songkhla (low-exposure region; n = 52) were recruited during a period of elevated regional air pollution, with long-term residence serving as a proxy for differential exposure to ambient air pollution environments. Partial least squares-discriminant analysis (PLS-DA) demonstrated separation between exposure groups (R2 = 0.873, Q2 = 0.447), indicating good model fit but only modest predictive ability. Eight urinary metabolites differed significantly (p &lt; 0.05), implicating pathways related to tryptophan metabolism, nucleotide metabolism, energy metabolism, and host\u2013microbial co-metabolism. L-arginine and L-cystathionine showed lower relative abundance in the high-exposure group, and six metabolites remained significant after Benjamini\u2013Hochberg false discovery rate correction. Following covariate adjustment, L-tryptophan, hippuric acid, xanthine, and 5-hydroxyindoleacetic acid (5-HIAA) remained significantly associated with the high-exposure group. Contrasting ambient air pollution exposure environments, indexed by regional PM2.5 concentrations, were associated with coordinated urinary metabolic alterations. Because long-term regional residence served as a proxy for individual-level exposure and diet and lifestyle differences between regions were not fully controlled, these findings should be interpreted as associations with contrasting regional exposure environments. Metabolite annotations remain putative and require validation in longitudinal studies with comprehensive pollutant characterization and individual-level exposure assessment.<\/jats:p>","DOI":"10.3390\/ijms27167193","type":"journal-article","created":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T07:57:26Z","timestamp":1786521446000},"page":"7193","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Urinary Metabolomic Alterations Associated with Contrasting Ambient Air Pollution Exposure in Thai Adults: An Untargeted 1H-NMR Study"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-7434-4859","authenticated-orcid":false,"given":"Blecious","family":"Zinan\u2019dala","sequence":"first","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Faculty of Clinical Sciences, Malawi College of Health Sciences, Lilongwe 3, Lilongwe P.O. Box 30368, Malawi"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anupon","family":"Iadnut","sequence":"additional","affiliation":[{"name":"Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Faculty of Medicine, Nation University, Chiang Mai 50210, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-7043-2922","authenticated-orcid":false,"given":"Chikondi","family":"Maluwa","sequence":"additional","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Faculty of Clinical Sciences, Malawi College of Health Sciences, Lilongwe 3, Lilongwe P.O. Box 30368, Malawi"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-7746-0106","authenticated-orcid":false,"given":"Puriwat","family":"Fakfum","sequence":"additional","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9262-0404","authenticated-orcid":false,"given":"Churdsak","family":"Jaikang","sequence":"additional","affiliation":[{"name":"Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Metabolomic Research Group for Forensic Medicine and Toxicology, Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giatgong","family":"Konguthaithip","sequence":"additional","affiliation":[{"name":"Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Metabolomic Research Group for Forensic Medicine and Toxicology, Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kanokwan","family":"Kulprachakarn","sequence":"additional","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wason","family":"Parklak","sequence":"additional","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hataichanok","family":"Chuljerm","sequence":"additional","affiliation":[{"name":"School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"638","DOI":"10.1080\/09603123.2025.2538500","article-title":"The burden of stroke attributable to ambient particulate matter pollution in China: Findings from the Global Burden of Disease Study 2021","volume":"36","author":"Wang","year":"2025","journal-title":"Int. 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