RT Journal Article
SR Electronic
T1 Toxic potential of ambient particulate matter in various urban areas of the world and its relation to chemical composition and emission sources
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4132
VO 44
IS Suppl 58
A1 Arian Saffari
A1 Nancy Daher
A1 Martin Shafer
A1 James Schauer
A1 Constantinos Sioutas
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P4132.abstract
AB Generation of reactive oxygen species (ROS) upon the interaction of toxic PM components with cells is believed to be one of the major pathways of oxidative stress induction. This study provides a global insight on the oxidative potential of ambient PM in different urban areas and size fractions. A cell-based (in-vitro) ROS assay is used to assess PM-induced oxidative potential and PM toxicity data from several previous studies in different urban locations (including Los Angeles, Long Beach, Riverside and Denver (USA), Milan (Italy), Beirut (Lebanon), Lahore (Pakistan) and Thessaloniki (Greece)) and in three different size ranges (i.e. quasi-ultrafine (PM0.25), fine (PM2.5) and coarse (PM2.5-10)) are combined and analyzed. As part of the analysis, the association of chemical components and corresponding PM sources with ROS activity is investigated. Moreover, the impact of particle size and possible effects of atmospheric aging on PM-induced redox activity are discussed. The results indicate overall higher levels of PM toxicity in developing areas of the world compared to developed countries. Smaller size ranges are generally associated with higher levels of PM toxicity, primarily due to the higher fraction of redox-active components in smaller size fractions. Transition metals (most notably Ni, V, Fe and Cu) as well as water soluble organic carbon (WSOC) are the species with highest and most frequent correlations with ROS activity, indicating the dominant effect of traffic emission sources, residual/fuel oil combustion and secondary organic aerosol generation on the induction of oxidative potential.