{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:46:06Z","timestamp":1787028366237,"version":"build-2736575974"},"reference-count":74,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2023,3,29]],"date-time":"2023-03-29T00:00:00Z","timestamp":1680048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Newton Fund NERC","award":["NE\/P014674\/1"],"award-info":[{"award-number":["NE\/P014674\/1"]}]},{"name":"Newton Fund NERC","award":["RDG6030008"],"award-info":[{"award-number":["RDG6030008"]}]},{"DOI":"10.13039\/501100004396","name":"Thailand Research Fund","doi-asserted-by":"publisher","award":["NE\/P014674\/1"],"award-info":[{"award-number":["NE\/P014674\/1"]}],"id":[{"id":"10.13039\/501100004396","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004396","name":"Thailand Research Fund","doi-asserted-by":"publisher","award":["RDG6030008"],"award-info":[{"award-number":["RDG6030008"]}],"id":[{"id":"10.13039\/501100004396","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Traffic is a major source of particulate pollution in large cities, and particulate matter (PM) level in Bangkok often exceeds the World Health Organisation limits. While PM2.5 and PM10 are both measured in Bangkok regularly, the sub-micron range of PM, of specific interest in regard to possible adverse health effects, is very limited. In the study, particle number concentration (PNC) was measured on public transport in Bangkok. A travel route through Bangkok using the state railway, the mass rapid transport underground system, the Bangkok Mass Transit System (BTS) Skytrain and public buses on the road network, with walking routes between, was taken whilst measuring particle levels with a hand-held concentration particle counter. The route was repeated 19 times covering different seasons during either morning or evening rush hours. The highest particle concentrations were found on the state railway, followed by the bus, the BTS Skytrain and the MRT underground with measured peaks of 350,000, 330,000, 33,000 and 9000 cm\u22123, respectively, though particle numbers over 100,000 cm\u22123 may be an underestimation due to undercounting in the instrument. Inside each form of public transport, particle numbers would peak when stopping to collect passengers (doors opening) and decay with a half-life between 2 and 3 min. There was a weak correlation between particle concentration on bus, train and BTS and Skytrain with carbon monoxide concentration, as measured at a fixed location in the city.<\/jats:p>","DOI":"10.3390\/ijerph20075316","type":"journal-article","created":{"date-parts":[[2023,3,30]],"date-time":"2023-03-30T02:23:46Z","timestamp":1680143026000},"page":"5316","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Particle Number Concentration Measurements on Public Transport in Bangkok, Thailand"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5908-0610","authenticated-orcid":false,"given":"James C.","family":"Matthews","sequence":"first","affiliation":[{"name":"Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, Cantock\u2019s Close, Bristol BS8 1TS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chalida","family":"Chompoobut","sequence":"additional","affiliation":[{"name":"Chulabhorn Research Institute, 54 Kamphaeng-Phet 6 Road, Laksi, Bangkok 10210, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panida","family":"Navasumrit","sequence":"additional","affiliation":[{"name":"Chulabhorn Research Institute, 54 Kamphaeng-Phet 6 Road, Laksi, Bangkok 10210, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7836-3344","authenticated-orcid":false,"given":"M. Anwar H.","family":"Khan","sequence":"additional","affiliation":[{"name":"Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, Cantock\u2019s Close, Bristol BS8 1TS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew D.","family":"Wright","sequence":"additional","affiliation":[{"name":"Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, Cantock\u2019s Close, Bristol BS8 1TS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mathuros","family":"Ruchirawat","sequence":"additional","affiliation":[{"name":"Chulabhorn Research Institute, 54 Kamphaeng-Phet 6 Road, Laksi, Bangkok 10210, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dudley E.","family":"Shallcross","sequence":"additional","affiliation":[{"name":"Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, Cantock\u2019s Close, Bristol BS8 1TS, UK"},{"name":"Department of Chemistry, University of the Western Cape, Robert Sobukwe Road, Bellville 7375, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1093\/neuonc\/nox163","article-title":"Long-term exposure to ambient air pollution and incidence of brain tumor: The European Study of Cohorts for Air Pollution Effects (ESCAPE)","volume":"20","author":"Andersen","year":"2018","journal-title":"Neuro-oncology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.neuro.2016.06.003","article-title":"Long-term exposure to ambient air pollution and incidence of brain tumours: The Danish Nurse Cohort","volume":"55","author":"Johansen","year":"2016","journal-title":"Neurotoxicology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1034","DOI":"10.1164\/rccm.200807-1043OC","article-title":"Concentrated ambient ultrafine particle exposure induces cardiac changes in young healthy volunteers","volume":"179","author":"Samet","year":"2009","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1093\/toxsci\/kfu063","article-title":"Controlled exposure of humans with metabolic syndrome to concentrated ultrafine ambient particulate matter causes cardiovascular effects","volume":"140","author":"Devlin","year":"2014","journal-title":"Toxicol. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1097\/EDE.0000000000000798","article-title":"Exposure to ambient ultrafine particles and nitrogen dioxide and incident hypertension and diabetes","volume":"29","author":"Bai","year":"2018","journal-title":"Epdemiology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1186\/s12989-015-0084-6","article-title":"Size-fractioned ultrafine particles and black carbon associated with autonomic dysfunction in subjects with diabetes or impaired glucose tolerance in Shanghai, China","volume":"12","author":"Sun","year":"2015","journal-title":"Part. Fibre Toxicol."},{"key":"ref_7","unstructured":"(2023, January 23). World Health Organisation Health Topics Air Pollution. Available online: https:\/\/www.who.int\/health-topics\/air-pollution."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1016\/S1470-2045(13)70487-X","article-title":"The carcinogenicity of outdoor pollution","volume":"14","author":"Loomis","year":"2013","journal-title":"Lancet Oncol."},{"key":"ref_9","first-page":"813","article-title":"Long-term concentrations of ambient air pollutants and incident lung cancer in California adults: Results from the AHSMOG study. Adventist Health Study on smog","volume":"106","author":"Beeson","year":"1998","journal-title":"Environ. Health Perspect."},{"key":"ref_10","first-page":"81","article-title":"Air pollution and lung cancer incidence in 17 European cohorts: Prospective analyses from the European Study of Cohorts for Air Pollution Effects (ESCAPE)","volume":"14","author":"Andersen","year":"2013","journal-title":"Lancet Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Consonni, D., Carugno, M., De Matteis, S., Nordio, F., Randi, G., Bazzano, M., Caporaso, N.E., Tucker, M.A., Bertazzi, P.A., and Pesatori, A.C. (2018). Outdoor particulate matter (PM10) exposure and lung cancer risk in the EAGLE study. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0203539"},{"key":"ref_12","first-page":"1030","article-title":"Long-term exposure to PM10 increases lung cancer risks: A cohort analysis","volume":"54","author":"Lee","year":"2022","journal-title":"Cancer Res. Treat. Off. J. Korean Cancer Assoc."},{"key":"ref_13","unstructured":"Krewski, D., Jerrett, M., Burnett, R.T., Ma, R., Hughes, E., Shi, Y., Turner, M.C., Pope III, C.A., Thurston, G., and Calle, E.E. (2009). Extended Follow-Up and Spatial Analysis of the American Cancer Society Study Linking Particulate Air Pollution and Mortality, Health Effects Institute."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1958","DOI":"10.1002\/ijc.30255","article-title":"Long-term exposure to fine particulate matter air pollution and the risk of lung cancer among participants of the Canadian National Breast Screening Study","volume":"139","author":"Tomczak","year":"2016","journal-title":"Int. J. Cancer"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1289\/EHP124","article-title":"The association between ambient fine particulate air pollution and lung cancer incidence: Results from the AHSMOG-2 study","volume":"125","author":"Gharibvand","year":"2017","journal-title":"Environ. Health Perspect."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1136\/thoraxjnl-2019-213722","article-title":"Association between particulate matter air pollution and lung cancer","volume":"75","author":"Zhang","year":"2020","journal-title":"Thorax"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1164\/rccm.202011-4063OC","article-title":"Air pollution, genetic factors, and the risk of lung cancer: A prospective study in the UK Biobank","volume":"204","author":"Huang","year":"2021","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1102","DOI":"10.1080\/10473289.2002.10470845","article-title":"Roadside particulate air pollution in Bangkok","volume":"52","author":"Jinsart","year":"2002","journal-title":"J. Air Waste Manag. Assoc."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Fold, N.R., Allison, M.R., Wood, B.C., Thao, P.T., Bonnet, S., Garivait, S., Kamens, R., and Pengjan, S. (2020). An assessment of annual mortality attributable to ambient PM2.5 in Bangkok, Thailand. Int. J. Environ. Res. Public Health, 17.","DOI":"10.3390\/ijerph17197298"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1007\/s00038-019-01202-7","article-title":"Health effects of ultrafine particles: A systematic literature review update of epidemiological evidence","volume":"64","author":"Ohlwein","year":"2019","journal-title":"Int. J. Public Health"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1038\/s12276-020-0403-3","article-title":"The health effects of ultrafine particles","volume":"52","author":"Schraufnagel","year":"2020","journal-title":"Exp. Mol. Med."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1007\/s11869-015-0356-1","article-title":"The importance of the exposure metric in air pollution epidemiology studies: When does it matter, and why?","volume":"9","author":"Dionisio","year":"2016","journal-title":"Air Qual. Atmos. Health"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.envint.2014.01.013","article-title":"Ultrafine particles in cities","volume":"66","author":"Kumar","year":"2014","journal-title":"Environ. Int."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"106135","DOI":"10.1016\/j.envint.2020.106135","article-title":"Ambient ultrafine particle concentrations and incidence of childhood cancers","volume":"145","author":"Lavigne","year":"2020","journal-title":"Environ. Int."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"012029","DOI":"10.1088\/1742-6596\/1322\/1\/012029","article-title":"Atmospheric potential gradient measurements from a rooftop in Bangkok","volume":"1322","author":"Matthews","year":"2019","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"79025","DOI":"10.1007\/s11356-022-20806-w","article-title":"Aerosol mass and size-resolved metal content in urban Bangkok, Thailand","volume":"29","author":"Matthews","year":"2022","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"281","DOI":"10.5194\/acp-4-281-2004","article-title":"Particle size distribution and particle mass measurements at urban, near-city and rural level in the Copenhagen area and Southern Sweden","volume":"4","author":"Ketzel","year":"2004","journal-title":"Atmos. Chem. Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5334","DOI":"10.1021\/es100008x","article-title":"Near-roadway air quality: Synthesizing the findings from real-world data","volume":"44","author":"Karner","year":"2010","journal-title":"Environ. Sci. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.atmosenv.2007.09.057","article-title":"Measurements and predictors of on-road ultrafine particle concentrations and associated pollutants in Los Angeles","volume":"42","author":"Fruin","year":"2008","journal-title":"Atmos. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"735","DOI":"10.1007\/s10661-022-10453-6","article-title":"Exposure characteristics of ultrafine particles on urban streets and its impact on pedestrians","volume":"194","author":"He","year":"2022","journal-title":"Environ. Monit. Assess."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2948","DOI":"10.1007\/s11356-015-5877-5","article-title":"Assessment of selected metals in the ambient air PM10 in urban sites of Bangkok (Thailand)","volume":"23","author":"Pongpiachan","year":"2016","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_32","unstructured":"Matthews, J., Navasumrit, P., Chaisatra, K., Chompoobut, C., Wright, M., Ruchirawat, M., and Shallcross, D. (2022, January 4\u20138). Aerosol size distribution and metal constituents in three sites in Bangkok. Proceedings of the EGU General Assembly Conference Abstracts, Vienna, Austria."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"10797","DOI":"10.1073\/pnas.1605941113","article-title":"Magnetite pollution nanoparticles in the human brain","volume":"113","author":"Maher","year":"2016","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4557","DOI":"10.1016\/S1352-2310(01)00194-7","article-title":"Determinants of fine particle (PM2.5) personal exposure levels in transport microenvironments, London, UK","volume":"35","author":"Adams","year":"2001","journal-title":"Atmos Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4781","DOI":"10.1016\/j.atmosenv.2007.02.002","article-title":"Fine particulate matter and carbon monoxide exposure concentrations in urban street transport microenvironments","volume":"41","author":"Kaur","year":"2007","journal-title":"Atmos. Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.atmosenv.2017.03.006","article-title":"Exposure to fine particulate, black carbon, and particle number concentration in transportation microenvironments","volume":"157","author":"Betancourt","year":"2017","journal-title":"Atmos. Environ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.atmosenv.2003.09.036","article-title":"Personal exposure to particulate air pollution in transport microenvironments","volume":"38","author":"Gulliver","year":"2004","journal-title":"Atmos. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6496","DOI":"10.1016\/j.atmosenv.2008.04.015","article-title":"Relative exposure to fine particulate matter and VOCs between transport microenvironments in Dublin: Personal exposure and uptake","volume":"42","author":"McNabola","year":"2008","journal-title":"Atmos Environ."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1289\/ehp.0901622","article-title":"Commuters\u2019 exposure to particulate matter air pollution is affected by mode of transport, fuel type, and route","volume":"118","author":"Zuurbier","year":"2010","journal-title":"Environ. Health Perspect."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.envint.2007.06.011","article-title":"Effects of travel mode on exposures to particulate air pollution","volume":"34","author":"Briggs","year":"2008","journal-title":"Environ. Int."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"e23","DOI":"10.1016\/S2468-2667(16)30021-4","article-title":"Levels of ambient air pollution according to mode of transport: A systematic review","volume":"2","author":"Cepeda","year":"2017","journal-title":"Lancet Public Health"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1080\/10473289.2011.622854","article-title":"Driver exposure to particulate matter in Bangkok","volume":"62","author":"Jinsart","year":"2012","journal-title":"J. Air Waste Manag. Assoc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"102470","DOI":"10.1016\/j.scs.2020.102470","article-title":"Personal exposure to airborne particles in transport micro-environments and potential health impacts: A tale of two cities","volume":"63","author":"Tran","year":"2020","journal-title":"Sustain. Cities Soc."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1396","DOI":"10.1016\/j.apr.2020.05.021","article-title":"The influence of school bus ventilation scenarios over in-cabin PM number concentration and air exchange rates","volume":"11","author":"Chaudhry","year":"2020","journal-title":"Atmos. Pollut. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1002\/asl.211","article-title":"Short range dispersion experiments using fixed and moving sources","volume":"10","author":"Shallcross","year":"2009","journal-title":"Atmos. Sci. Letts."},{"key":"ref_46","first-page":"99","article-title":"Air quality in enclosed railway stations","volume":"170","author":"Thornes","year":"2017","journal-title":"Proc. Inst. Civ. Eng.-Transp."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"4579","DOI":"10.1021\/acs.est.8b06980","article-title":"Exposure to air pollution inside electric and diesel-powered passenger trains","volume":"53","author":"Andersen","year":"2019","journal-title":"Environ. Sci. Technol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2511","DOI":"10.1080\/10643389.2012.685348","article-title":"Particle emissions from rail traffic: A literature review","volume":"43","author":"Abbasi","year":"2013","journal-title":"Crit. Rev. Environ. Sci. Technol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.envpol.2017.03.072","article-title":"Ultrafine particle air pollution inside diesel-propelled passenger trains","volume":"226","author":"Abramesko","year":"2017","journal-title":"Environ. Pollut."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.atmosenv.2017.02.015","article-title":"Exposure to ultrafine particles and black carbon in diesel-powered commuter trains","volume":"155","author":"Jeong","year":"2017","journal-title":"Atmos. Environment."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"7995","DOI":"10.1016\/j.atmosenv.2007.08.002","article-title":"Levels of particulate air pollution, its elemental composition, determinants and health effects in metro systems","volume":"41","author":"Nieuwenhuijsen","year":"2007","journal-title":"Atmos. Environment."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Vichiensan, V., Wasuntarasook, V., Hayashi, Y., Kii, M., and Prakayaphun, T. (2022). Urban rail transit in Bangkok: Chronological development review and impact on residential property value. Sustainability, 14.","DOI":"10.3390\/su14010284"},{"key":"ref_53","unstructured":"(2021, May 28). Thailand Ministry of Transport Data Catalogue Home Page. Available online: https:\/\/stat.mot.go.th."},{"key":"ref_54","unstructured":"(2021, September 29). Thailand Office of Transport and Traffic Policy and Planning. Available online: http:\/\/www.otp.go.th\/uploads\/tiny_uploads\/ProjectOTP\/2560\/Projcet01\/2.2-TDS_Exsum_EN_Final_20180515.pdf."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1741","DOI":"10.4209\/aaqr.2012.11.0305","article-title":"Temporal and spatial variations in ambient air quality during 1996\u20132009 in Bangkok, Thailand","volume":"13","author":"Watcharavitoon","year":"2013","journal-title":"Aerosol Air Qual. Res."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"051009","DOI":"10.1088\/2515-7620\/ab8f11","article-title":"Long-term trend of regional passenger road transport demand and emission estimation under exhaust emission regulation scenario in Thailand","volume":"2","author":"Cheewaphongphan","year":"2020","journal-title":"Environ. Res. Commun."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"109978","DOI":"10.1016\/j.envres.2020.109978","article-title":"Using miniaturised scanning mobility particle sizers to observe size distribution patterns of quasi-ultrafine aerosols inhaled during city commuting","volume":"191","author":"Moreno","year":"2020","journal-title":"Environ. Res."},{"key":"ref_58","unstructured":"(2022, November 03). Thailand Pollution Control Department Thailand\u2019s Air Quality and Situation Reports. Available online: air4thai.pcd.go.th\/webV2\/."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"3367","DOI":"10.1016\/j.atmosenv.2006.01.050","article-title":"Particulate air pollution in six Asian cities: Spatial and temporal distributions, and associated sources","volume":"40","author":"Oanh","year":"2006","journal-title":"Atmos. Environ."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1016\/j.atmosenv.2013.06.001","article-title":"Characterization of gaseous pollutants and PM2. 5 at fixed roadsides and along vehicle traveling routes in Bangkok Metropolitan Region","volume":"77","author":"Oanh","year":"2013","journal-title":"Atmos. Environ."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1463","DOI":"10.1016\/S0021-8502(02)00090-3","article-title":"The Particle Detection Efficiency of the TSI\u20133007 Condensation Particle Counter","volume":"33","author":"Koponen","year":"2002","journal-title":"J. Aerosol. Sci."},{"key":"ref_62","unstructured":"(2023, March 10). Royal Thai Government Website. Available online: https:\/\/www.thaigov.go.th\/news\/contents\/details\/45401."},{"key":"ref_63","unstructured":"(2023, March 10). BTS Service Timetable. Available online: https:\/\/www.bts.co.th\/service\/timetable.html."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/j.trd.2009.06.002","article-title":"L Levels of ultrafine particles in the Taipei Rapid Transit System","volume":"14","author":"Cheng","year":"2009","journal-title":"Transp. Res. Part D Transp. Environ."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.scitotenv.2014.12.013","article-title":"Exposure to airborne particulate matter in the subway system","volume":"511","author":"Martins","year":"2015","journal-title":"Sci. Total Environ."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1007\/s00508-019-1516-3","article-title":"Fine and ultrafine particle exposure during commuting by subway in Vienna","volume":"131","author":"Posselt","year":"2019","journal-title":"Wien Klin Wochenschr."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"105188","DOI":"10.1016\/j.envint.2019.105188","article-title":"PM2.5 on the London Underground","volume":"134","author":"Smith","year":"2020","journal-title":"Environ. Int."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1016\/S1001-0742(09)60121-2","article-title":"Commuter exposure to BTEX in public transportation modes in Bangkok, Thailand","volume":"22","author":"Ongwandee","year":"2010","journal-title":"J. Environ. Sci."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1177\/09544097JRRT407","article-title":"On-board measurements of particulate matter emissions from a passenger train","volume":"225","author":"Fridell","year":"2011","journal-title":"Proc. Inst. Mech. Eng. Part F J. Rail Rapid Transit."},{"key":"ref_70","doi-asserted-by":"crossref","unstructured":"Khan, M.A.H., Bonifcio, S., Clowes, J.J., Foulds, A., Holland, R., Matthews, J.C., Percival, C.J., and Shallcross, D.E. (2021). Investigation of biofuel as a potential renewable energy source. Atmosphere, 12.","DOI":"10.3390\/atmos12101289"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1016\/j.atmosenv.2015.06.035","article-title":"Chemical characterization of biofuel exhaust emissions","volume":"116","author":"Jedynska","year":"2015","journal-title":"Atmos. Environment."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1080\/02786826.2022.2042467","article-title":"How effective are face coverings in reducing transmission of COVID-19?","volume":"56","author":"Robinson","year":"2022","journal-title":"Aerosol. Sci. Technol."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1038\/d41586-019-02938-1","article-title":"Face masks could raise pollution risks","volume":"574","author":"Huang","year":"2019","journal-title":"Nature"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1080\/02786826.2021.1905149","article-title":"Evaluation of particle filtration efficiency of commercially available materials for homemade face mask usage","volume":"55","author":"Joo","year":"2021","journal-title":"Aerosol. Sci. 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