Fig. 1. The location of the air cleaner and measurement instruments in the classrooms (a) without an air cleaner, (b) with an air cleaner and (c) with two air cleaners.
Fig. 5. Average (a) PM2.5 and (b) PM10 in classrooms with 1 or 2 air cleaners at different outdoor PM2.5 and PM10 for five air cleaners with CADRs between 13.5 and 14.4 m3/min.
Fig. 7. CO2 concentrations in classrooms without an air cleaner, with an air cleaner and two air cleaners (Model F).
Fig. 8. Average CO2 concentrations in classrooms of 2nd grade students without an air cleaner, with an air cleaner and two air cleaners in the (a) S school and (b) W school.
Fig. 2. (a) PM2.5 and PM10 changes in a classroom of S elementary school and (b) the size distributions of particles in the empty and occupied classroom in class and lunch time.
Fig. 3. (a) PM2.5 and (b) PM10 changes with time in classrooms without an air cleaner, with an air cleaner and two air cleaners (F model).
Fig. 6. (a) PM2.5 and (b) PM10 in/out concentration ratio for classrooms without air cleaner, with one air cleaner and two air cleaners.
Fig. 4. (a) Average PM2.5 and (b) PM10 in classrooms without an air cleaner, with an air cleaner and two air cleaners for eight air cleaners.
Table 1. Specification of the tested air cleaners.
Table 2. Experimental data and weather information based on the average of class hours.
References
- Agarwal, N., and Nagendra, S.S. (2016). Modelling of particulate matters distribution inside the multilevel urban classrooms in tropical climate for exposure assessment, Building and Environment, 102, 73-82. https://doi.org/10.1016/j.buildenv.2016.03.015
- Anderson, J.O., Thundiyil, J.G., and Stolbach, A. (2012). Clearing the air: a review of the effects of particulate matter air pollution on human health, Journal of Medical Toxicology, 8(2), 166-175. https://doi.org/10.1007/s13181-011-0203-1
- Bonjour, S., Adair-Rohani, H., Wolf, J., Bruce, N.G., Mehta, S., Pruss-Ustun, A., Lahiff, M., Rehfuess, E.A., Mishra, V., and Smith, K.R. (2013). Solid fuel use for household cooking: country and regional estimates for 1980-2010, Environmental Health Perspectives, 121(7), 784-790. https://doi.org/10.1289/ehp.1205987
- Buonanno, G., Fuoco, F.C., Morawska, L., and Stabile, L. (2013). Airborne particle concentrations at schools measured at different spatial scales, Atmospheric Environment, 67, 38-45. https://doi.org/10.1016/j.atmosenv.2012.10.048
- Chithra, V.S., and Nagendra, S.M.S. (2012). Indoor air quality investigations in a naturally ventilated school building located close to an urban roadway in Chennai, India, Building and Environment, 54, 159-167. https://doi.org/10.1016/j.buildenv.2012.01.016
- Chithra V.S., and Shiva N.S.M. (2018). A review of scientific evidence on indoor air of school building: pollutants, sources, health effects and management, Asian Journal of Atmospheric Environment, 12(2), 87-108. https://doi.org/10.5572/ajae.2018.12.2.87
- Choi J., Park, R., Lee, H.M., Lee, S., Jo, D., Jeong, J., Henze, D.K., Woo, J.H., Ban, S.J., Lee, M.D., Lim, C.S., Park, M.K., Shin, H.J., Cho, S., Peterson, D., and Song, C.K. (2019). Impacts of local vs. trans-boundary emissions from drifferent sectors on PM2.5 exposure in South Korea during the KORUS-AQ campaign, Atmospheric Environment, 203, 196-205. https://doi.org/10.1016/j.atmosenv.2019.02.008
- Diapouli, E., Chaloulakou, A., Mihalopoulos, N., and Spyrellis, N. (2008). Indoor and outdoor PM mass and number concentrations at schools in the Athens area, Environmental Monitoring and Assessment, 136(1-3), 13-20. https://doi.org/10.1007/s10661-007-9724-0
- Fromme, H., Twardella, D., Dietrich, S., Heitmann, D., Schierl, R., Liebl, B., and Ruden, H. (2007). Particulate matter in the indoor air of classrooms-exploratory results from Munich and surrounding area, Atmospheric Environment, 41(4), 854-866. https://doi.org/10.1016/j.atmosenv.2006.08.053
- Gaidajis, G., and Angelakoglou, K. (2009). Indoor air quality in university classrooms and relative environment in terms of mass concentrations of particulate matter, Journal of Environmental Science and Health, Part A, 44(12), 1227-1232. https://doi.org/10.1080/10934520903139936
- Godwin, C., and Batterman, S. (2007). Indoor air quality in Michigan schools, Indoor Air, 17(2), 109-121. https://doi.org/10.1111/j.1600-0668.2006.00459.x
- Guo, H., Morawska, L., He, C., Zhang, Y.L., Ayoko, G., and Cao, M. (2010). Characterization of particle number concentrations and PM2.5 in a school: influence of outdoor air pollution on indoor air, Environmental Science and Pollution Research, 17(6), 1268-1278. https://doi.org/10.1007/s11356-010-0306-2
- Hajat, A., Hsia, C., and O'Neill, M.S. (2015). Socioeconomic disparities and air pollution exposure: a global review, Current Environmental Health Reports, 2(4), 440-450. https://doi.org/10.1007/s40572-015-0069-5
- Jang, C.S., Lee, T.J., and Kim, D.S. (2006). Classification of pollution patterns in high school classrooms using disjoint principal component analysis, Journal of Korean Society for Atmospheric Environment, 22(6), 808-820. (in Korean with English abstract)
- Janssen, N.A., van Vliet, P.H., Aarts, F., Harssema, H., and Brunekreef, B. (2001). Assessment of exposure to traffic related air pollution of children attending schools near motorways, Atmospheric Environment, 35(22), 3875-3884. https://doi.org/10.1016/S1352-2310(01)00144-3
- Jeong, J., and Lee, H. (2010). Study on the characteristics of air quality in the classroom of elementary school and its control methods, Journal of Korean Society of Environmental Engineers, 32(4), 311-322. (in Korean with English abstract)
- KACA (2018). Room Air Cleaner Standard, Seoul, Korea, Korea Air Cleaning Association (SPS-KACA002-132).
- Klepeis, N.E., Nelson, W.C., Ott, W.R., Robinson, J.P., Tsang, A.M., Switzer, P., Behar, J.V., Hern, S.C., and Engelmann, W.H. (2001). The national human activity pattern survey (NHAPS): a resource for assessing exposure to environmental pollutants, Journal of Exposure Science and Environmental Epidemiology, 11, 231-252. https://doi.org/10.1038/sj.jea.7500165
- Lee, S.C., Guo, H., Li, W.M., and Chan, L.Y. (2002). Inter-comparison of air pollutant concentrations in different indoor environments in Hong Kong, Atmospheric Environment, 36(12), 1929-1940. https://doi.org/10.1016/S1352-2310(02)00176-0
- Lippmann, M. (2013). Exposure science in the 21st century: a vision and a strategy, Journal of Exposure Science and Environmental Epidemiology, 23(1), 1. https://doi.org/10.1038/jes.2012.109
- Madureira, J., Paciencia, I., and Fernandes, E.O. (2012). Levels and indoor-outdoor relationships of size-specific particulate matter in naturally ventilated Portuguese schools, Journal of Toxicology and Environmental Health, Part A, 75(22-23), 1423-1436. https://doi.org/10.1080/15287394.2012.721177
- Oeder, S., Dietrich, S., Weichenmeier, I., Schober, W., Pusch, G., Jorres, R.A., Schierl, R., Nowak, D., Fromme, H., Behrendt, H., and Buters, J.T.M. (2012). Toxicity and elemental composition of particulate matter from outdoor and indoor air of elementary schools in Munich, Germany, Indoor Air, 22(2), 148-158. https://doi.org/10.1111/j.1600-0668.2011.00743.x
- Pegas, P.N., Nunes, T., Alves, C.A., Silva, J.R., Vieira, S.L.A., Caseiro, A., and Pio, C.A. (2012). Indoor and outdoor characterisation of organic and inorganic compounds in city centre and suburban elementary schools of Aveiro, Portugal, Atmospheric Environment, 55, 80-89. https://doi.org/10.1016/j.atmosenv.2012.03.059
- Pope, C.A. III, Renlund, D.G., Kfoury, A.G., May, H.T., and Horne, B.D. (2008). Relation of heart failure hospitalization to exposure to fine particulate air pollution, American Journal of Cardiology, 102(9), 1230-1234. https://doi.org/10.1016/j.amjcard.2008.06.044
- Souza, D.Z., Vasconcellos, P.C., Lee, H., Aurela, M., Saarnio, K., Teinila, T., and Hillamo, R. (2014). Composition of PM2.5 and PM10 collected at urban sites in Brazil, Aerosol and Air Quality Research, 14, 168-176. https://doi.org/10.4209/aaqr.2013.03.0071