{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T22:32:51Z","timestamp":1791066771474,"version":"4.1.0"},"reference-count":50,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,10]],"date-time":"2025-09-10T00:00:00Z","timestamp":1757462400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Faculty of Medicine Ramathibodi Hospital, Mahidol University, and the ThaiHealth Promotion Foundation","award":["66-P1-0472"],"award-info":[{"award-number":["66-P1-0472"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Background: Since the emergence of e-cigarettes on the market in the early 2000s, the prevalence of e-cigarette use has increased globally. The health risks of using e-cigarettes have been increasingly revealed; however, the health effects on non-users exposed to e-cigarettes are less known. Methods: A systematic review was conducted of peer-reviewed articles from 2004 to October 2024 from PubMed and Embase. We focused on the studies that described health outcome measures among non-smokers\/vapers exposed to secondhand e-cigarettes. We excluded animal studies and those that did not include human participants. We also omitted studies with financial conflicts of interest with the tobacco industry. Results: Of the 8635 studies we found in our search, 16 were included in the final review. Study designs included in our review included a case study, a cohort, eight experimental, four cross-sectional studies, and two observational studies. Health outcome measures were self-reported health symptoms and biomarkers. Ten out of fourteen studies examined respiratory health risks, six described immunological effects, two examined cardiovascular risks, and one explored mental health effects. Self-reported health symptoms such as bronchitis, shortness of breath, asthma, throat irritations, ear infections, and mental health disorders were observed among secondhand e-cigarette exposures when compared with controls. Biomarker measures varied among studies, except for cotinine concentrations of non-smokers\/vapers exposed to secondhand e-cigarettes, which were likely to be higher than non-exposed. However, all studies encountered potential limitations. Conclusions: Our review found that secondhand e-cigarette exposure is not harmless and may have negative health consequences. However, higher-quality prospective studies remain essential to examine long-term secondhand exposure.<\/jats:p>","DOI":"10.3390\/ijerph22091408","type":"journal-article","created":{"date-parts":[[2025,9,10]],"date-time":"2025-09-10T08:43:54Z","timestamp":1757493834000},"page":"1408","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Health Effects from Secondhand Exposure to E-Cigarettes: A Systematic Review of Peer-Reviewed Articles from 2004\u20132024"],"prefix":"10.3390","volume":"22","author":[{"given":"Roengrudee","family":"Patanavanich","sequence":"first","affiliation":[{"name":"Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chawaphat","family":"Thatasawakul","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kamolnut","family":"Youngcharoen","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Veerapattra","family":"Soponvashira","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panpetch","family":"Pichetsin","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"100506","DOI":"10.1016\/j.puhip.2024.100506","article-title":"The global prevalence of E-cigarettes in youth: A comprehensive systematic review and meta-analysis","volume":"7","author":"Salari","year":"2024","journal-title":"Public Health Pract."},{"key":"ref_2","first-page":"1","article-title":"E-cigarettes evolution over the past 10 years: From the generation to the 5th generation or \u201cToy pod\u201d and cartoon-based marketing strategy targeting younger smokers","volume":"6","author":"Lapyai","year":"2024","journal-title":"J. Public Health Health Sci. Res."},{"key":"ref_3","first-page":"147","article-title":"Vaping associated with healthy food words: A content analysis of Twitter","volume":"8","author":"Majmundar","year":"2018","journal-title":"Addict. Behav. Rep."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1972","DOI":"10.1161\/CIRCULATIONAHA.114.007667","article-title":"E-cigarettes: A scientific review","volume":"129","author":"Grana","year":"2014","journal-title":"Circulation"},{"key":"ref_5","first-page":"125","article-title":"The science of flavour in tobacco products","volume":"1015","author":"Green","year":"2019","journal-title":"World Health Organ. Tech. Rep. Ser."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.1093\/ntr\/ntae123","article-title":"A Review of the Toxicity of Ingredients in e-Cigarettes, Including Those Ingredients Having the FDA\u2019s \u201cGenerally Recognized as Safe (GRAS)\u201d Regulatory Status for Use in Food","volume":"26","author":"Kassem","year":"2024","journal-title":"Nicotine Tob. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e119","DOI":"10.1136\/tobaccocontrol-2018-054537","article-title":"Health claims made in vape shops: An observational study and content analysis","volume":"28","author":"Wagoner","year":"2019","journal-title":"Tob. Control"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"107741","DOI":"10.1016\/j.addbeh.2023.107741","article-title":"Perceptions of e-cigarettes among Australian adolescents, young adults, and adults","volume":"144","author":"Thoonen","year":"2023","journal-title":"Addict. Behav."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"E41","DOI":"10.5888\/pcd14.160567","article-title":"Perceptions of Harm to Children Exposed to Secondhand Aerosol From Electronic Vapor Products, Styles Survey, 2015","volume":"14","author":"Nguyen","year":"2017","journal-title":"Prev. Chronic Dis."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.ypmed.2016.10.019","article-title":"Adolescents\u2019 attitudes towards e-cigarette ingredients, safety, addictive properties, social norms, and regulation","volume":"94","author":"Gorukanti","year":"2017","journal-title":"Prev. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1136\/tobaccocontrol-2019-055368","article-title":"It\u2019s Just Steam: A qualitative analysis of New Zealand ENDS users\u2019 perceptions of secondhand aerosol","volume":"30","author":"Haggart","year":"2021","journal-title":"Tob. Control"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2621617","DOI":"10.17061\/phrp2621617","article-title":"A systematic review of the health risks from passive exposure to electronic cigarette vapour","volume":"26","author":"Hess","year":"2016","journal-title":"Public Health Res. Pract."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.envres.2014.09.005","article-title":"Cigarettes vs. e-cigarettes: Passive exposure at home measured by means of airborne marker and biomarkers","volume":"135","author":"Sureda","year":"2014","journal-title":"Environ. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"91","DOI":"10.3109\/08958378.2012.758197","article-title":"Acute impact of active and passive electronic cigarette smoking on serum cotinine and lung function","volume":"25","author":"Flouris","year":"2013","journal-title":"Inhal. Toxicol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3600","DOI":"10.1016\/j.fct.2012.07.025","article-title":"Acute effects of electronic and tobacco cigarette smoking on complete blood count","volume":"50","author":"Flouris","year":"2012","journal-title":"Food Chem. Toxicol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"300","DOI":"10.1186\/s12931-020-01569-9","article-title":"Use of electronic cigarettes and secondhand exposure to their aerosols are associated with asthma symptoms among adolescents: A cross-sectional study","volume":"21","author":"Alnajem","year":"2020","journal-title":"Respir. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1601","DOI":"10.1111\/ina.12841","article-title":"Environmental and individual exposure to secondhand aerosol of electronic cigarettes in confined spaces: Results from the TackSHS Project","volume":"31","author":"Amalia","year":"2021","journal-title":"Indoor Air"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"158668","DOI":"10.1016\/j.scitotenv.2022.158668","article-title":"Exposure to secondhand aerosol from electronic cigarettes at homes: A real-life study in four European countries","volume":"854","author":"Amalia","year":"2023","journal-title":"Sci. Total Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"114490","DOI":"10.1016\/j.envres.2022.114490","article-title":"Passive exposure to electronic cigarette aerosol in pregnancy: A case study of a family","volume":"216","author":"Fu","year":"2023","journal-title":"Environ. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.chest.2018.10.005","article-title":"Secondhand Exposure to Aerosols From Electronic Nicotine Delivery Systems and Asthma Exacerbations Among Youth With Asthma","volume":"155","author":"Bayly","year":"2019","journal-title":"Chest"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Costantino, S., Torre, A., Foti Randazzese, S., Mollica, S.A., Motta, F., Busceti, D., Ferrante, F., Caminiti, L., Crisafulli, G., and Manti, S. (2024). Association between Second-Hand Exposure to E-Cigarettes at Home and Exacerbations in Children with Asthma. Children, 11.","DOI":"10.3390\/children11030356"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Farrell, K.R., Weitzman, M., Karey, E., Lai, T.K.Y., Gordon, T., and Xu, S. (2022). Passive exposure to e-cigarette emissions is associated with worsened mental health. BMC Public Health, 22.","DOI":"10.1186\/s12889-022-13470-9"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1136\/thoraxjnl-2021-217041","article-title":"Secondhand nicotine vaping at home and respiratory symptoms in young adults","volume":"77","author":"Islam","year":"2022","journal-title":"Thorax"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1018","DOI":"10.1177\/00034894221129013","article-title":"Association of e-Cigarette Exposure with Pediatric Otitis Media Recurrence","volume":"132","author":"Lam","year":"2023","journal-title":"Ann. Otol. Rhinol. Laryngol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e033","DOI":"10.1097\/EE9.0000000000000033","article-title":"Cardiac Autonomic Effects of Secondhand Exposure to Nicotine from Electronic Cigarettes: An Exploratory Study","volume":"3","author":"Lee","year":"2019","journal-title":"Environ. Epidemiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"943","DOI":"10.4187\/respcare.08596","article-title":"The Immediate Physiological Effects of E-Cigarette Use and Exposure to Secondhand E-Cigarette Vapor","volume":"66","author":"McClelland","year":"2021","journal-title":"Respir. Care"},{"key":"ref_27","first-page":"1861580","article-title":"An RCT of acute health effects in COPD-patients after passive vape exposure from e-cigarettes","volume":"8","author":"Bendstrup","year":"2020","journal-title":"Eur. Clin. Respir. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"108963","DOI":"10.1016\/j.envres.2019.108963","article-title":"Passive exposure of non-smokers to E-Cigarette aerosols: Sensory irritation, timing and association with volatile organic compounds","volume":"182","author":"Tzortzi","year":"2020","journal-title":"Environ. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"882","DOI":"10.1016\/j.envpol.2018.08.069","article-title":"The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real-world conditions","volume":"243","author":"Volesky","year":"2018","journal-title":"Environ. Pollut."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1772","DOI":"10.1093\/ntr\/ntaa094","article-title":"Indoor Air Quality and Passive E-cigarette Aerosol Exposures in Vape-Shops","volume":"22","author":"Son","year":"2020","journal-title":"Nicotine Tob. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1146\/annurev-publhealth-040119-094043","article-title":"Effects of Electronic Cigarettes on Indoor Air Quality and Health","volume":"41","author":"Li","year":"2020","journal-title":"Annu. Rev. Public Health"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"171829","DOI":"10.1016\/j.scitotenv.2024.171829","article-title":"Characteristics of second-hand exposure to aerosols from e-cigarettes: A literature review since 2010","volume":"926","author":"Cui","year":"2024","journal-title":"Sci. Total Environ."},{"key":"ref_33","unstructured":"Eaton, D.L., Kwan, L.Y., and Stratton, K. (2018). Public Health Consequences of E-Cigarettes, National Academies Press."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"10","DOI":"10.18332\/tpc\/131111","article-title":"A review of constituents identified in e-cigarette liquids and aerosols","volume":"7","author":"Eshraghian","year":"2021","journal-title":"Tob. Prev. Cessat."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1111\/add.13183","article-title":"Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes","volume":"111","author":"Havel","year":"2016","journal-title":"Addiction"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"4654","DOI":"10.1007\/s11356-018-3975-x","article-title":"Influence of electronic cigarette vaping on the composition of indoor organic pollutants, particles, and exhaled breath of bystanders","volume":"26","author":"Marco","year":"2019","journal-title":"Environ. Sci. Pollut. Res. Int."},{"key":"ref_37","first-page":"414","article-title":"Urinary cotinine levels of electronic cigarette (e-cigarette) users","volume":"26","author":"Tamer","year":"2016","journal-title":"Toxicol. Mech. Methods"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e2462544","DOI":"10.1001\/jamanetworkopen.2024.62544","article-title":"Nicotine Exposure From Smoking Tobacco and Vaping Among Adolescents","volume":"8","author":"Hammond","year":"2025","journal-title":"JAMA Netw. Open"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1010","DOI":"10.1289\/ehp.1104413","article-title":"Exposure to secondhand smoke outside of a bar and a restaurant and tobacco exposure biomarkers in nonsmokers","volume":"120","author":"Bernert","year":"2012","journal-title":"Environ. Health Perspect."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1093\/ntr\/ntq237","article-title":"Comparison of urine cotinine and the tobacco-specific nitrosamine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and their ratio to discriminate active from passive smoking","volume":"13","author":"Goniewicz","year":"2011","journal-title":"Nicotine Tob. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1136\/bmj.38146.427188.55","article-title":"Passive smoking and risk of coronary heart disease and stroke: Prospective study with cotinine measurement","volume":"329","author":"Whincup","year":"2004","journal-title":"BMJ"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1665","DOI":"10.1056\/NEJM199306103282303","article-title":"Association between exposure to environmental tobacco smoke and exacerbations of asthma in children","volume":"328","author":"Chilmonczyk","year":"1993","journal-title":"N. Engl. J. Med."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Wang, Y., Huang, Z., Luo, D., Tian, L., Hu, M., and Xiao, S. (2020). Respiratory Symptoms and Urinary Cotinine Levels in Pre-school Children Exposed to Environmental Tobacco Smoke. Front. Public Health, 8.","DOI":"10.3389\/fpubh.2020.587193"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Kim, S. (2016). Overview of Cotinine Cutoff Values for Smoking Status Classification. Int. J. Environ. Res. Public Health, 13.","DOI":"10.3390\/ijerph13121236"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1173","DOI":"10.1016\/j.amepre.2025.02.007","article-title":"Trends in U.S. E-cigarette Sales Measured in Milligrams of Nicotine, 2019\u20132024","volume":"68","author":"Ali","year":"2025","journal-title":"Am. J. Prev. Med."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1355","DOI":"10.1093\/ntr\/ntad033","article-title":"Trends in Nicotine Strength in Electronic Cigarettes Sold in the United States by Flavor, Product Type, and Manufacturer, 2017\u20132022","volume":"25","author":"Wang","year":"2023","journal-title":"Nicotine Tob. Res."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"e88","DOI":"10.1136\/tobaccocontrol-2020-056367","article-title":"Nicotine delivery and cigarette equivalents from vaping a JUULpod","volume":"31","author":"Prochaska","year":"2022","journal-title":"Tob. Control"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1136\/tc-2023-058033","article-title":"Bigger, stronger and cheaper: Growth in e-cigarette market driven by disposable devices with more e-liquid, higher nicotine concentration and declining prices","volume":"34","author":"Diaz","year":"2025","journal-title":"Tob. Control"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"World Health Organization (2025). WHO Report on the Global Tobacco Epidemic, 2025: Warning About the Dangers of Tobacco, World Health Organization. Available online: https:\/\/www.who.int\/publications\/i\/item\/9789240112063.","DOI":"10.2471\/B09466"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1404","DOI":"10.1093\/ntr\/ntae094","article-title":"Are People More Likely to Vape or Smoke Indoors? A Population Survey of Adults in England","volume":"26","author":"Jackson","year":"2024","journal-title":"Nicotine Tob. Res."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/22\/9\/1408\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:42:56Z","timestamp":1760035376000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/22\/9\/1408"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,10]]},"references-count":50,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["ijerph22091408"],"URL":"https:\/\/doi.org\/10.3390\/ijerph22091408","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,10]]}}}