An apportionment method for the Oxydative Potential to the atmospheric PM sources: application to a one-year study in Chamonix, France
Atmospheric Chemistry and Physics Discussions
The particulate matter (PM) induces cellular oxidative stress in vivo and so lead to adverse health outcome. The oxidative potential (OP) of the PM appears to be a more relevant proxy of the health impact of the aerosol rather than the total mass concentration. However, the relative contributions of the emission's sources of aerosols to the OP are still poorly known. In order to better quantify the impact of each PM source to the air quality, we sampled aerosols in a French city for one year
... ity for one year (year 2014, 115 samples). A coupled analysis with detailed chemical speciation (more than 100 species, including organic and carbonaceous compounds, ions, metals and aethalomether measurements) and two OP assays (ascorbic acid (AA) and dithiothreitiol (DTT)) in a simulated lung fluid (SLF) were performed in these samples. We developed in this study a new statistical model using a coupled approach with Positive Matrix Factorisation (PMF) and multiple linear regressions to attribute a redox-activity per PM sources. Our results highlight the importance of the Biomass burning and Vehicular sources to explain the observed OP for both assays. In general, we see a different contribution of the sources when considering the OP AA, OP DTT or the mass of the PM10. Moreover, some significant differences are observed between the DTT and AA tests that emphasized the chemical specificities of the two tests and the need of a standardized approach for the future studies on epidemiology or toxicology of the PM.