Indoor-to-outdoor levels of size-segregated particulate matter in urban microenvironments
Title: Indoor-to-outdoor levels of size-segregated particulate matter in urban microenvironments
Summary: Martins V., Faria T., Diapouli E., Manousakas M., Eleftheriadis K., Viana M., Almeida S.M.
Airborne particulate matter (PM) is an issue of increasing importance due to its effects on human health , especially to children who represent a vulnerable group, with developing immune and respiratory systems. The harmful potential of particles is related to their ability in crossing the respiratory system, depositing in the deepest and most defenceless regions of the lung, carrying several toxic compounds .
This study aimed to evaluate the relationship between indoor and outdoor size distributions of particles and its chemical constituents affecting children exposure. This characterization was carried out in homes and schools located in Lisbon city centre.
The aerosol size distribution was obtained using a Personal Cascade Impactor Sampler (PCIS). Particles were separated in five aerodynamic diameter ranges: <0.25; 0.25–0.5; 0.5–1.0; 1.0–2.5; and >2.5 μm. Moreover, the data collected simultaneously by a medium volume sampler, for the coarser size fraction (2.5–10 μm), was used to complement the results obtained by the PCIS. The samples were representative of weekly (5-day) occupied-hours. Major and trace elements were analysed by X-Ray Fluorescence. Organic (OC) and elemental carbon (EC) concentrations were determined by thermo-optical method.
The highest indoor PM10 levels were registered in the schools (33–97 μg/m3), while the lowest values were measured in the homes (11–38 μg/m3). In general, PM10 concentrations inside the homes were lower than those measured outside, while the opposite was observed in the schools. On average, PM mass in homes was more concentrated in the smallest size range, while in the schools the coarser particles represented most of the PM mass (Fig.1).
OC represented the major component in the indoor of both homes and schools for all size ranges, accounting on average for 14.0–68.7% of the total mass. EC represented the second largest component for PM0.25. For the remaining size ranges, the second most abundant specie was the Ca in the case of the schools, which could be related to the use of chalk on blackboards. For homes, this characterization depended largely on the particle size.
The sources of carbonaceous aerosols can be determined by analysing the correlation between OC and EC. A significant correlation was observed for PM2.5-10 (R2 = 0.79), PM1.0-2.5 (R2 = 0.69) and PM0.5-1.0 (R2 = 0.59), suggesting that they come from related sources or are transported to the site together.
The sea salt and mineral dust were present dominantly in the coarse mode, as expected.
The mass size distribution of the particles and its chemical constituents was very heterogeneous, not only among locations (home vs. school) but also between indoor and outdoor microenvironments.
This work was supported by LIFE Index-Air project (LIFE15 ENV/PT/000674). Authors acknowledge the FCT support through the UID/Multi/04349/2013 project and the PhD grant SFRH/BD/129149/2017. This work reflects only the authors’ view.
 Shaughnessy, W.J., et al (2015). Atmos. Environ. 123: 102-111.
 Valavanidis, A., et al. (2008). J. Environ. Sci. Heal. Part C, 26:339-62.
Type of publication: Oral Abstract of ICEH 2019 (Lisbon, Portugal, 25-27 September)
How to cite: Martins V., Faria T., Diapouli E., Manousakas M., Eleftheriadis K., Viana M., Almeida S.M. (2019) Indoor-to-outdoor levels of size-segregated particulate matter in urban microenvironments. ICEH 2019 – 4th International Congress on Environmental Health, Lisbon, Portugal, 25-27 September.
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