Articles | Volume 14, issue 9
Atmos. Chem. Phys., 14, 4459–4472, 2014
Atmos. Chem. Phys., 14, 4459–4472, 2014

Research article 07 May 2014

Research article | 07 May 2014

Indoor/outdoor relationships and mass closure of quasi-ultrafine, accumulation and coarse particles in Barcelona schools

M. Viana1, I. Rivas1,2,3,4,7, X. Querol1, A. Alastuey1, J. Sunyer2,3,4,5, M. Álvarez-Pedrerol2,3,4, L. Bouso2,3,4, and C. Sioutas6 M. Viana et al.
  • 1Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
  • 2Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
  • 3Universitat Pompeu Fabra (UFP), Barcelona, Spain
  • 4CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
  • 5Hospital del Mar Research Institute (IMIM), Barcelona, Spain
  • 6University of Southern California, Los Angeles, CA, USA
  • 7Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona (UAB), Edifici C Campus de la UAB, 08193 Bellaterra Cerdanyola, Spain

Abstract. The mass concentration, chemical composition and sources of quasi-ultrafine (quasi-UFP, PM0.25), accumulation (PM0.25–2.5) and coarse mode (PM2.5–10) particles were determined in indoor and outdoor air at 39 schools in Barcelona (Spain). Quasi-UFP mass concentrations measured (25.6 μg m−3 outdoors, 23.4 μg m−3 indoors) are significantly higher than those reported in other studies, and characterised by higher carbonaceous and mineral matter contents and a lower proportion of secondary inorganic ions. Results suggest that quasi-UFPs in Barcelona are affected by local sources in the schools, mainly human activity (e.g. organic material from textiles, etc., contributing 23–46% to total quasi-UFP mass) and playgrounds (in the form of mineral matter, contributing about 9% to the quasi-UFP mass). The particle size distribution patterns of toxicologically relevant metals and major aerosol components was characterised, displaying two modes for most elements and components, and one mode for inorganic salts (ammonium nitrate and sulfate) and elemental carbon (EC). Regarding metals, Ni and Cr were partitioned mainly in quasi-UFPs and could thus be of interest for epidemiological studies, given their high redox properties. Exposure of children to quasi-UFP mass and chemical species was assessed by comparing the concentrations measured at urban background and traffic areas schools. Finally, three main indoor sources across all size fractions were identified by assessing indoor / outdoor ratios (I / O) of PM species used as their tracers: human activity (organic material), cleaning products, paints and plastics (Cl source), and a metallic mixed source (comprising combinations of Cu, Zn, Co, Cd, Pb, As, V and Cr). Our results support the need to enforce targeted legislation to determine a minimum "safe" distance between major roads and newly built schools to reduce exposure to traffic-derived metals in quasi-UFPs.

Final-revised paper