AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Relation Between Carbonaceous Aerosol Characterization and Lung Injury Endpoints in an In Vivo Model
ANDRÉS HENRÍQUEZ, Matías Tagle, Felipe Reyes, Thomas Kuhlbusch, Bryan Hellack, Claudio Hetz, Pedro Oyola, Centro Mario Molina
Abstract Number: 254 Working Group: Health Related Aerosols
Abstract Particulate air pollution is a major problem to public health (Brunekreef and Holgate. 2002). Lately, the carbonaceous compounds of aerosols have attracted interest not only for their implications in the adverse health effects, but also for the contribution to global climate change. The carbonaceous aerosol is a dominant component of fine particle matter (PM$_2.5), and consists of both elemental and organic carbon. Elemental carbon (EC) is produced by incomplete combustion and comprises graphitic carbon particles, otherwise organic carbon (OC) is a mixture of many compounds; several of them with known health hazard. Nevertheless, there are still gaps in knowledge about how the carbonaceous components induce pulmonary toxic responses.
We collected samples of PM$_2.5 in the two most populated cities in Chile (Santiago and Concepción) during summer and winter in 2010. Samples were analyzed for mass concentration, EC, OC, monosaccharides, $^(14)C/$^(12)C, among others at NILU (Norwegian Institute for Air Research) and Lund University. With these measurements, a source apportionment of fossil and non-fossil (Biomass) OC and EC was done using Latin Hypercube Sampling Method (Szidat et al. 2009).
Additionally to the aerosol characterization and PM$_2.5 sampling, toxic responses of constant doses of PM$_2.5 in an in vivo model were measured using acute lung injury endpoints as lactate dehydrogenase (LDH), total protein and cell count in the bronchoalveolar lavage of Sprague Dawley rats exposed by intratracheal instillation. Also, we analyzed the relation with oxidative stress measuring the intrinsic PM$_2.5 potential to produce hydroxyl radical generation detected by Electron Paramagnetic Resonance spectrometry (EPR).
The results point out that PM$_2.5 concentration does not correlate with in vivo endpoints but with EPR. Levoglucosan concentrations, a widely used wood smoke tracer (Naeher et al. 2007), correlate with in vivo endpoints but not with the EPR signals (or concentration). Among sources, non fossil OC and Fossil EC correlated significantly with two in vivo endpoints.
In conclusion, this work highlights the importance of carbonaceous compounds and its relation with health effects of PM$_2.5.