{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T15:41:19Z","timestamp":1776181279096,"version":"3.50.1"},"reference-count":18,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2014,7,3]],"date-time":"2014-07-03T00:00:00Z","timestamp":1404345600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>This study demonstrates an application of cluster analysis to constant ambient air monitoring data of four pollutants in the Kanto region: NOx, photochemical oxidant (Ox), suspended particulate matter, and non-methane hydrocarbons. Constant ambient air monitoring can provide important information about the surrounding atmospheric pollution. However, at the same time, ambient air monitoring can place a significant financial burden on some autonomous communities. Thus, it has been necessary to reduce both the number of monitoring stations and the number of chemicals monitored. To achieve this, it is necessary to identify those monitoring stations and pollutants that are least significant,  while minimizing the loss of data quality and mitigating the effects on the determination of any spatial and temporal trends of the pollutants. Through employing cluster analysis,  it was established that the ambient monitoring stations in the Kanto region could be clustered topologically for NOx and Ox into eight groups. From the results of this analysis,  it was possible to identify the similarities in site characteristics and pollutant behaviors.<\/jats:p>","DOI":"10.3390\/ijerph110706844","type":"journal-article","created":{"date-parts":[[2014,7,3]],"date-time":"2014-07-03T11:13:17Z","timestamp":1404385997000},"page":"6844-6855","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["A Cluster Analysis of Constant Ambient Air Monitoring Data from the Kanto Region of Japan"],"prefix":"10.3390","volume":"11","author":[{"given":"Atsushi","family":"Iizuka","sequence":"first","affiliation":[{"name":"Research Center for Sustainable Science and Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan"},{"name":"Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo,  5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shintaro","family":"Shirato","sequence":"additional","affiliation":[{"name":"Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo,  5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsushi","family":"Mizukoshi","sequence":"additional","affiliation":[{"name":"Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo,  5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan"},{"name":"Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku,  Tokyo 135-0064, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miyuki","family":"Noguchi","sequence":"additional","affiliation":[{"name":"Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo,  5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan"},{"name":"Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akihiro","family":"Yamasaki","sequence":"additional","affiliation":[{"name":"Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yukio","family":"Yanagisawa","sequence":"additional","affiliation":[{"name":"Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo,  5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2014,7,3]]},"reference":[{"key":"ref_1","first-page":"607","article-title":"Application of multiple regression analysis to pollutant concentrations from roadside and ambient air quality monitoring stations","volume":"29","author":"Ito","year":"2007","journal-title":"JARI Res. J."},{"key":"ref_2","first-page":"55","article-title":"Alteration of the SPM pollution in Pref.Yamanashi compared with the south Kanto area","volume":"50","author":"Shimizu","year":"2006","journal-title":"Annu. Rep. Yamanashi Inst. Public Health"},{"key":"ref_3","first-page":"74","article-title":"Results of air pollution monitoring for 1988\u20132007 in Pref. Yamanashi","volume":"52","author":"Shimizu","year":"2008","journal-title":"Annu. Rep. Yamanashi Inst. Public Health"},{"key":"ref_4","unstructured":"Everitt, B.S. (1993). Cluster Analysis, Heinemann Education. [3rd ed.]."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/S0266-9838(96)00017-2","article-title":"The ozone patterns in the aerological basin of Milan (Italy)","volume":"11","author":"Lavecchia","year":"1996","journal-title":"Environ. Software"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"5464","DOI":"10.1016\/j.atmosenv.2006.03.062","article-title":"Examination of pollution trends in Santiago de Chile with cluster analysis of PM10 and ozone data","volume":"40","author":"Gramsch","year":"2006","journal-title":"Atmos. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1452","DOI":"10.1016\/j.atmosenv.2005.10.051","article-title":"Classification of PM10 distributions in Taiwan","volume":"40","author":"Lu","year":"2006","journal-title":"Atmos. Environ."},{"key":"ref_8","first-page":"684","article-title":"Cluster analysis applied to atmospheric PM10 concentration data for determination of sources and spatial patterns in ambient air-quality of Kathmandu valley","volume":"93","author":"Giri","year":"2007","journal-title":"Curr. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1039\/b210172f","article-title":"Cluster analysis of Delhi's ambient air quality data","volume":"5","author":"Saksena","year":"2003","journal-title":"J. Environ. Monit."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"672","DOI":"10.1002\/env.946","article-title":"Analysis of air quality monitoring networks by functional clustering","volume":"19","author":"Ignaccolo","year":"2008","journal-title":"Environmetrics"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"366","DOI":"10.3402\/tellusb.v57i5.16561","article-title":"Atmospheric transport of carbon dioxide to a baseline monitoring station in northern Finland","volume":"57","author":"Eneroth","year":"2005","journal-title":"Tellus"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s10453-007-9081-z","article-title":"Spatial variation of airborne pollen over south-east France: Characterization and implications for monitoring networks management","volume":"24","author":"Rieux","year":"2008","journal-title":"Aerobiologia"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1293","DOI":"10.1007\/s00216-007-1711-3","article-title":"Study of traffic-emitted lead pollution of soil and plants using different fuzzy clustering algorithms","volume":"390","author":"Einax","year":"2008","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_14","unstructured":"Ministry of the Environment of Japan Available online: http:\/\/www.env.go.jp\/air\/osen\/manual_5th\/."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6099","DOI":"10.5194\/acp-7-6099-2007","article-title":"A climatology of surface ozone in the extra tropics: Cluster analysis of observations and model results","volume":"7","author":"Tarasova","year":"2007","journal-title":"Atmos. Chem. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1134\/S0001433808040087","article-title":"Seasonal and daily cycles of surface ozone in the extratropical latitudes","volume":"44","author":"Zvyagintsev","year":"2007","journal-title":"Izv. Atmos. Ocean. Phys."},{"key":"ref_17","unstructured":"The Ministry of Land, Infrastructure and Transport, Kanto Regional Development Bureau Road Investor Relations Site. Available online: http:\/\/www.mlit.go.jp\/road\/ir\/ir-data\/ir-data.html."},{"key":"ref_18","first-page":"313","article-title":"Meteorological factors which causes high SPM concentrations in wide area in rainy season\u2014Analysis of the case in July 1997","volume":"20","author":"Kaneyasu","year":"2005","journal-title":"Earozoru Kenkyu"}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/11\/7\/6844\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:13:15Z","timestamp":1760217195000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/11\/7\/6844"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,7,3]]},"references-count":18,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2014,7]]}},"alternative-id":["ijerph110706844"],"URL":"https:\/\/doi.org\/10.3390\/ijerph110706844","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,7,3]]}}}