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Relationship between indoor and outdoor size-fractionated particulate matter in urban microenvironments: Levels, chemical composition and sources


Exposure to particulate matter (PM) has been associated with adverse health outcomes, particularly in susceptible population groups such as children. This study aims to characterise children’s exposure to PM and its chemical constituents. Size-segregated aerosol samples (PM0.25, PM0.25–0.5, PM0.5–1.0, PM1.0–2.5 and PM2.5–10) were collected in the indoor and outdoor of homes and schools located in Lisbon (Portugal). Organic and elemental carbon (OC and EC) were determined by a thermo-optical method, whereas major and trace elements were analysed by X-Ray Fluorescence. In school, the children were exposed to higher PM concentrations than in home, which might be associated not only to the elevated human occupancy but also to outdoor infiltration. The pattern of PM mass size distribution was dependent on the location (home vs. school and indoor vs. outdoor). The presence of EC in PM0.25 and OC in PM0.25–0.5 was linked to traffic exhaust emissions. OC and EC in PM2.5–10 may be explained by their adhesion to the surface of coarser particles. Generally, the concentrations of mineral and marine elements increased with increasing PM size, while for anthropogenic elements happened the opposite. In schools, the concentrations of mineral matter, anthropogenic elements and marine aerosol were higher than in homes. High mineral matter concentrations found in schools were related to the close proximity to busy roads and elevated human occupancy. Overall, the results suggest that exposure to PM is relevant and highlights the need for strategies that provide healthier indoor environments, principally in schools.


  • 2.1. Study area
    2.2. Sampling sites
    2.3. Instrumentation and measurements
    2.4. Sample analysis
    2.5. Statistical analysis

  • 3.1. PM mass concentrations
    3.1.1. Size distribution
    3.1.2. Indoor–outdoor interplay
    3.2. PM chemical composition
    3.2.1. Carbonaceous constituents
    3.2.2. Major and trace elements


Date: April 2020

Author : Vânia Martins, Tiago Faria, Evangelia Diapouli, Manousos Ioannis Manousakas, Konstantinos Eleftheriadis, Mar Viana, Susana Marta Almeida

Geographical area: Portugal, Lisbon

Type of publication : Article

Language : EN