Exposure to combustion-derived air pollution aerosols has been shown to have many adverse effects on human health, including the impact of cellular oxidative stress. In this toxicological study we developed a new method to assess the contribution of different sources of ambient aerosols to the oxidative potential (OP) of particulate mass (PM), using a long time series of PM10 samples.
The OP was measured on filter samples collected over a full year in the Alpine valley city of Chamonix (France), using two OP protocols: ascorbic acid (AA) and dithiothreitol (DTT) assays. We used PMF analysis from an advanced source-receptor model to obtain source apportionment, and inverted the OP measurements in order to attribute both an intrinsic OP to the sources and the evolution of the source contributions to OPs over the year.
Our results highlight the importance of both biomass burning and vehicular sources as the major contributors to OP in both assay methods. Significant differences were observed between the DTT and AA protocols. This emphasizes the chemical specificities of these tests and the need for a standardized approach for future studies of the epidemiology or toxicology of PM.
The article was published in Atmospheric Chemistry and Physics:
An apportionment method for the oxidative potential of atmospheric particulate matter sources: application to a one-year study in Chamonix, France