Environmental Science and Pollution Research

, Volume 17, Issue 6, pp 1268–1278 | Cite as

Characterization of particle number concentrations and PM2.5 in a school: influence of outdoor air pollution on indoor air

  • Hai Guo
  • Lidia Morawska
  • Congrong He
  • Yanli L. Zhang
  • Godwin Ayoko
  • Min Cao
Research Article


Background, Aim and Scope

The impact of air pollution on school children’s health is currently one of the key foci of international and national agencies. Of particular concern are ultrafine particles which are emitted in large quantities, contain large concentrations of toxins and are deposited deeply in the respiratory tract.

Materials and methods

In this study, an intensive sampling campaign of indoor and outdoor airborne particulate matter was carried out in a primary school in February 2006 to investigate indoor and outdoor particle number (PN) and mass concentrations (PM2.5), and particle size distribution, and to evaluate the influence of outdoor air pollution on the indoor air.


For outdoor PN and PM2.5, early morning and late afternoon peaks were observed on weekdays, which are consistent with traffic rush hours, indicating the predominant effect of vehicular emissions. However, the temporal variations of outdoor PM2.5 and PN concentrations occasionally showed extremely high peaks, mainly due to human activities such as cigarette smoking and the operation of mower near the sampling site. The indoor PM2.5 level was mainly affected by the outdoor PM2.5 (r = 0.68, p < 0.01), whereas the indoor PN concentration had some association with outdoor PN values (r = 0.66, p < 0.01) even though the indoor PN concentration was occasionally influenced by indoor sources, such as cooking, cleaning and floor polishing activities. Correlation analysis indicated that the outdoor PM2.5 was inversely correlated with the indoor to outdoor PM2.5 ratio (I/O ratio; r = −0.49, p < 0.01), while the indoor PN had a weak correlation with the I/O ratio for PN (r = 0.34, p < 0.01).

Discussion and conclusions

The results showed that occupancy did not cause any major changes to the modal structure of particle number and size distribution, even though the I/O ratio was different for different size classes. The I/O curves had a maximum value for particles with diameters of 100–400 nm under both occupied and unoccupied scenarios, whereas no significant difference in I/O ratio for PM2.5 was observed between occupied and unoccupied conditions. Inspection of the size-resolved I/O ratios in the preschool centre and the classroom suggested that the I/O ratio in the preschool centre was the highest for accumulation mode particles at 600 nm after school hours, whereas the average I/O ratios of both nucleation mode and accumulation mode particles in the classroom were much lower than those of Aitken mode particles.

Recommendations and perspectives

The findings obtained in this study are useful for epidemiological studies to estimate the total personal exposure of children, and to develop appropriate control strategies for minimising the adverse health effects on school children.


I/O ratios Particle number concentration PM2.5 Aitken mode particles School 



We would like to thank Mr. Mick Dobbyn, the principal of the school, for his support during the whole sampling campaign period. We are grateful to the representatives of the Parents and Citizens Association of the school, for their valuable suggestions on the project. The technical assistance received from Dr. Rohan Jayaratne and Dr. Graham Johnson was greatly appreciated. This project was funded by Queensland Transport and the data analysis was supported by Research Grants 87PK and PB0G from the Hong Kong Polytechnic University.


  1. Afshari A, Matson U, Ekberg LE (2005) Characterization of indoor sources of fine and ultrafine particles: a study conducted in a full-scale chamber. Indoor Air 15:141–150CrossRefGoogle Scholar
  2. Andersen ZJ, Wahlin P, Raaschou-Nielsen O, Ketzel M, Scheike T, Loft S (2008) Size distribution and total number concentration of ultrafine and accumulation mode particles and hospital admissions in children and the elderly in Copenhagen, Denmark. Occup Environ Med 65(7):458–466CrossRefGoogle Scholar
  3. Annesi-Maesano I, Moreau D, Caillaud D, Lavaud F, Le Moullec Y, Taytard A, Pauli G, Charpin D (2007) Residential proximity fine particles related to allergic sensitisation and asthma in primary school children. Respir Med 101(8):1721–1729CrossRefGoogle Scholar
  4. Baron PA, Willeke K (2001) Aerosol measurement: principles, techniques, and applications, 2nd edn. Wiley, New YorkGoogle Scholar
  5. Blondeau P, Lordache V, Poupard O, Genin D, Allard F (2004) Relationship between outdoor and indoor air quality in eight French schools. Indoor Air 15:2–12CrossRefGoogle Scholar
  6. Branis M, Rezacova M, Domasova M (2005) The effect of outdoor air and indoor human activity on mass concentrations of PM10, PM2.5, and PM1 in a classroom. Environ Res 99(2):143–149CrossRefGoogle Scholar
  7. Branis M, Safranek J, Hytychova A (2009) Exposure of children to airborne particulate matter of different size fractions during indoor physical education at school. Build Environ 44(6):1246–1252CrossRefGoogle Scholar
  8. Chao CYH, Wan MP, Cheng ECK (2003) Penetration coefficient and deposition rate as a function of particle size in non-smoking naturally ventilated residences. Atmos Environ 37:4233–4241CrossRefGoogle Scholar
  9. Chen LC, Wu CY, Qu QS et al (1995) Number concentration and mass concentration as determinants of biological response to inhaled irritant particles. Inhal Toxicol 7:577–588CrossRefGoogle Scholar
  10. Cleland V, Timperio A, Salmon J, Hume C, Baur LA, Crawford D (2009) Predictors of time spent outdoors among children: 5-year longitudinal findings. J Epidemiol Community Health. doi: 10.1136/jech.2009.087460 Google Scholar
  11. Department of the Environment, Water, Heritage and the Arts (DEWHA) (2001) Air toxics and indoor air quality in Australia. State of Knowledge Report, Environment Australia, Canberra, AustraliaGoogle Scholar
  12. Diapouli E, Chaloulakou A, Spyrellis N (2007) Levels of ultrafine particles in different microenvironments—implications to children exposure. Sci Total Environ 388(1–3):128–136Google Scholar
  13. Finlayson-Pitts BJ, Finlayson-Pitts JN Jr (2000) Chemistry of the upper and lower atmosphere: theory, experiments and applications. Academic, OrlandoGoogle Scholar
  14. Franck U, Herbarth O, Wehner B, Wiedensohler A, Manjarrez M (2003) How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions? Indoor Air 13(2):174–181CrossRefGoogle Scholar
  15. Franck U, Tuch T, Manjarrez M, Wiedensohler A, Herbarth O (2006) Indoor and outdoor submicrometer particles: exposure and epidemiologic relevance (“the 3 indoor Ls”). Environ Toxicol 21(6):606–613CrossRefGoogle Scholar
  16. Fromme H, Twardella D, Dietrich S, Heitmann D, Schierl R, Liebl B, Ruden H (2007) Particulate matter in the indoor air of classrooms—exploratory results from Munich and surrounding area. Atmos Environ 41(4):854–866CrossRefGoogle Scholar
  17. Fromme H, Diemer J, Dietrich S, Cyrys J, Heinrich J, Lang W, Kiranoglu M, Twardella D (2008) Chemical and morphological properties of particulate matter (PM10, PM2.5) in school classrooms and outdoor air. Atmos Environ 42(27):6597–6605CrossRefGoogle Scholar
  18. Gehin E, Ramalho O, Kirchner S (2008) Size distribution and emission rate measurement of fine and ultrafine particle from indoor human activities. Atmos Environ 42(35):8341–8352CrossRefGoogle Scholar
  19. Godish T (2004) Air quality, 4th edn. Lewis, Boca RatonGoogle Scholar
  20. Gold DR, Gamokosh AI, Pope CA, Dockery DW, McDonnell WF, Serrano P, Retama A, Castillejos M (1999) Particulate and ozone pollutant effects on the respiratory function of children in southwest Mexico City. Epidemiology 10(1):8–16CrossRefGoogle Scholar
  21. Guo H, Morawska L, He CR, Gilbert D (2008) Impact of ventilation scenario on air exchange rates and on indoor particle number concentrations in an air-conditioned classroom. Atmos Environ 42:757–768CrossRefGoogle Scholar
  22. He C, Morawska L, Hitchins J, Gilbert D (2004) Contribution from indoor sources to particle number and mass concentrations in residential houses. Atmos Environ 38:3405–3415CrossRefGoogle Scholar
  23. He C, Morawska L, Gilbert D (2005) Particle deposition rates in residential houses. Atmos Environ 39(21):3891–3899CrossRefGoogle Scholar
  24. Hinds WC (1999) Aerosol technology, 2nd edn. Wiley, New YorkGoogle Scholar
  25. Hussein T, Hameri K, Heikkinen MSA, Kulmala M (2005) Indoor and outdoor particle size characterization at a family house in Espoo-Finland. Atmos Environ 39:3697–3709CrossRefGoogle Scholar
  26. Hussein T, Glytsos T, Ondracek J, Dohanyosova P, Zdimal V, Hameri K, Lazaridis M, Smolik J, Kulmala M (2006) Particle size characterization and emission rates during indoor activities in a house. Atmos Environ 40:4285–4307CrossRefGoogle Scholar
  27. Jamriska M, Morawska L, Clark B (2000) The effect of ventilation and filtration on submicormeter particulates in an indoor environment. Indoor Air 10:19–26CrossRefGoogle Scholar
  28. Jenkins PL, Phillips TJ, Mulberg JM, Hui SP (1992) Activity patterns of Californians: use of and proximity to indoor pollutant sources. Atmos Environ 26A:2141–2148Google Scholar
  29. John K, Karnae S, Crist K, Kim M, Kulkarni A (2007) Analysis of trace elements and ions in ambient fine particulate matter at three elementary schools in Ohio. JAWMA 57(4):394–406Google Scholar
  30. Jones AP (1999) Indoor air quality and health. Atmos Environ 33:4535–4564CrossRefGoogle Scholar
  31. Kingham S, Durand M, Harrison J, Cavanagh J, Epton M (2008) Temporal variations in particulate exposure to wood smoke in a residential school environment. Atmos Environ 42(19):4619–4631CrossRefGoogle Scholar
  32. Koponen IK, Asmi A, Keronen P, Puhto K, Kulmala M (2001) Indoor air measurement campaign in Helsinki, Finland 1999—the effect of outdoor air pollution on indoor air. Atmos Environ 35:1465–1477CrossRefGoogle Scholar
  33. Kousa A, Kukkonen J, Karppinen A, Aarnio P, Koskentalo T (2002) A model for evaluating the population exposure to ambient air pollution in an urban area. Atmos Environ 36:2109–2119CrossRefGoogle Scholar
  34. Lee SC, Guo H, Li WM, Chan LY (2002) Inter-comparison of air pollutant concentrations in different indoor environments in Hong Kong. Atmos Environ 36:1929–1940CrossRefGoogle Scholar
  35. Leickly FE (2003) Children, their school environment, and asthma. Ann Allergy Asthma Immun 90:3–5CrossRefGoogle Scholar
  36. Martuzievicius D, Grinshpun SA, Lee T, Hu SH, Biswas P, Reponen T, LeMasters G (2008) Traffic-related PM2.5 aerosol in residential houses located near major highways: indoor versus outdoor concentrations. Atmos Environ 42:6575–6585CrossRefGoogle Scholar
  37. Mathews TG (1987) Environmental chamber test methodology for characterizing organic vapors from solid emission sources. Atmos Environ 21:321–329CrossRefGoogle Scholar
  38. Morawska L, He C, Hitchins J, Mengersen K, Gilbert D (2003) Characteristics of particle number and mass concentrations in residual houses in Brisbane. Australia Atmos Environ 37:4195–4203Google Scholar
  39. Morawska L, He C, Johnson G, Guo H, Uhde E, Ayoko G (2009) Ultrafine particles in indoor air of a school: possible role of secondary organic aerosols. Environ Sci Technol 43:9103–9109CrossRefGoogle Scholar
  40. Oberdorster G, Gelein RM, Ferin J et al (1995) Association of particulate air pollution and acute mortality: involvement of ultrafine particles. Inhal Toxicol 7:111–124CrossRefGoogle Scholar
  41. Oravisjarvi K, Rautio A, Ruuskanen J, Tiittanen P, Timonen KL (2008) Air pollution and PEF measurements of children in the vicinity of a steel works. Boreal Environ Res 13(2):93–102Google Scholar
  42. Parker JL, Larson RR, Eskelson E, Wood EM, Veranth JM (2008) Particle size distribution and composition in a mechanically ventilated school building during air pollution epiodes. Indoor Air 18:386–393CrossRefGoogle Scholar
  43. Penttinen P, Timonen KL, Tiittanen P, Mirme A, Ruuskanen J, Pekkanen J (2001) Number concentration and size of particles in urban air: effects on spirometric lung function in adult asthmatic subjects. Environ Health Perspect 109(4):319–323CrossRefGoogle Scholar
  44. Pope CA III (1991) Respiratory hospital admissions associated with PM-10 pollution in Utah, Salt Lake, and Cache Valleys. Arch Environ Health 46:90–97Google Scholar
  45. Pope CA III, Dockery DW (1999) Epidemiology of particle effects. In: Holgate ST, Samet JM, Koren HS, Maynard RL (eds) Air pollution and health. Academic, San DiegoGoogle Scholar
  46. Ritowski ZD, Morawska L, Bofinger ND, Hitchins J (1998) Submicrometer and supermicrometer particulate emission from spark ignition vehicles. Environ Sci Technol 31:3845–3852Google Scholar
  47. Robinson J, Nelson WC (1995) National human activity pattern survey data base. United States Environmental Protection Agency, Research Triangle ParkGoogle Scholar
  48. Samet JM, Speizer FE, Bishop Y et al (1981) The relationship between air pollution and emergency room visits in an industrial community. J Air Pollut Control Assoc 31:236–240Google Scholar
  49. Sanchez DC, Mason M, Norris C (1987) Methods and characterization of organic emissions from an indoor material. Atmos Environ 21:337–345CrossRefGoogle Scholar
  50. Sawant AA, Na K, Zhu X, Cocker K, Butt S, Song C, Cocker DR III (2004) Characterization of PM2.5 and selected gas-phase compounds at multiple indoor and outdoor sites in Mira Loma. California Atmos Environ 38:6269–6278Google Scholar
  51. Schwartz J (1991) Particulate air pollution and daily mortality in Detroit. Environ Res 56:204–213CrossRefGoogle Scholar
  52. Thornburg J, Ensor DS, Rodos CE, Lawless PA, Sparks LE, Mosley RB (2001) Penetration of particles into buildings and associated physical factors. Part I: model development and computer simulations. Aerosol Sci Technol 34:284–296Google Scholar
  53. Vette AF, Rea AW, Lawless PA, Rodes CE, Evans G, Highsmith VR, Sheldon L (2001) Characterization of indoor-outdoor aerosol concentration relationships during the Fresno PM exposure studies. Aerosol Sci Technol 34:118–126Google Scholar
  54. Wallace L (1996) Indoor particles: a review. JAWMA 46:98–126Google Scholar
  55. Wallace L (2000) Real-time monitoring of particles, PAH, and CO in an occupied townhouse. Appl Occup Environ Hyg 15:39–47CrossRefGoogle Scholar
  56. Wallace L (2006) Indoor sources of ultrafine and accumulation mode particles: size distributions, size-resolved concentrations, and source strengths. Aerosol Sci Technol 40(5):348–360CrossRefGoogle Scholar
  57. Weichenthal S, Dufresne A, Infante-Rivard C (2007) Indoor ultrafine particles and childhood asthma: exploring a potential public health concern. Indoor Air 17(2):81–91CrossRefGoogle Scholar
  58. World Health Organization (WHO) (2005) WHO air quality guidelines global update. Report on a working group meeting, Bonn, Germany, 18–20 OctoberGoogle Scholar
  59. Xue J, McCurdy D, Spengler J, Ozkaynak H (2004) Understanding variability in time spent in selected locations for 7-12-year old children. J Expo Anal Environ Epidemiol 14:222–233CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Hai Guo
    • 1
    • 2
  • Lidia Morawska
    • 1
  • Congrong He
    • 1
  • Yanli L. Zhang
    • 2
  • Godwin Ayoko
    • 1
  • Min Cao
    • 1
  1. 1.International Laboratory for Air Quality and HealthQueensland University of TechnologyBrisbaneAustralia
  2. 2.Department of Civil and Structural EngineeringThe Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China

Personalised recommendations