10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Exposure of Children to Particulate Matter and Chemical Elements in Urban Environment
Tiago Faria, Marina Almeida-Silva, VÂNIA MARTINS, Inês Cunha-Lopes, Carolina Correia, Catarina Galinha, Célia Alves, Susana Marta Almeida, C2TN, IST, Universidade de Lisboa, Portugal
Abstract Number: 1500 Working Group: Aerosol Exposure
Abstract Introduction Particulate matter (PM) is a concern due to the adverse health effects it causes on human health. These effects are linked to the chemical components particles contain and their size and the efficiency of pulmonary deposition. Children spend more than 80% of their time indoors. Therefore, it is necessary to develop the best strategies to reduce PM exposure in various microenvironments in order to reduce health effects. The objective of this study was to quantify the daily exposure of children to PM and their chemical compounds considering different size fractions.
Methodology Ten children aged 5 to 9 living and studying in the city of Lisbon were selected to be part of this study using personal particle samplers for 3 days.
The particles were collected on Teflon filters using a personal cascade impactor (PCIS) connected to a Leland Legacy SKC pump which sampled particles in the size ranges <0.25, 0.25-0.5, 0.5-1, 1-2.5 and > 2.5 μm. The mass concentrations of the particles were determined gravimetrically. All samples were chemically analyzed by ICP-MS in order to determine the concentration of major and trace elements present in PM. In addition to this sampler, the children carried a monitor to make real-time measurements of PM2.5 concentrations, a particle number counter to measure the number concentration of particles between 10nm and 1μm, and a microaethalometer to measure black carbon concentrations. These equipments were accompanied by a GPS that registered the coordinates of the routes of the children. At the same time, the children fill a logbook every 15 minutes, indicating the main activities carried out indoors and outdoors, as well as the activities carried out by others that can affect the exposure, such as food confection or smoking.
Results The results of activity logs and GPS were combined with the mass and numerical concentrations of PM and black carbon in order to identify the microenvironments that contributed most to children's exposure. The analysis of the filters allowed to evaluate the size distribution of the particles and to calculate the children's exposure to different chemical elements. The inhaled dose was calculated considering the measured concentrations, the time activity patterns of each child and the inhalation rate. The results showed the importance of the indoor environment, especially of the house and the classroom, for children's exposure to particles.
Conclusions This study allowed understanding the children exposure to PM in the various microenvironments where they remain and the respective inhaled dose. The study of the particle size distribution and their chemical constituents was an essential input for dosimetry models that aim to evaluate the particles that reach the different regions of the body and thus estimate potential health effects.
Acknowledgements This work was funded by the European Union through the LIFE Index-Air Project (LIFE15 ENV/PT/000674). C2TN/IST authors gratefully acknowledge the FCT support through the UID/Multi/04349/2013 project.