Seasonal Variations and Chemical Predictors of Oxidative Potential (OP) of Particulate Matter (PM), for Seven Urban French Sites

Abstract

Epidemiological studies suggest that the main part of chronic effects from air pollution is likely to be linked with particulate matter (PM). Oxidative potential (OP) of PM is gaining strong interest as a promising health exposure metric. This study combined atmospheric detailed composition results obtained for seven different urban background environments over France to examine any possible common feature in OP seasonal variations obtained using two assays (acid ascorbic (AA) and dithiothreitol (DTT)) along a large set of samples ( N > 700 ). A remarkable homogeneity in annual cycles was observed with a higher OP activity in wintertime at all investigated sites. Univariate correlations were used to link the concentrations of some major chemical components of PM and their OP. Four PM components were identified as OP predictors: OC, EC, monosaccharides and Cu. These species are notably emitted by road transport and biomass burning, targeting main sources probably responsible for the measured OP activity. The results obtained confirm that the relationship between OP and atmospheric pollutants is assay- and location-dependent and, thus, the strong need for a standardized test, or set of tests, for further regulation purposes.

The influence of chemical composition, aerosol acidity, and metal dissolution on the oxidative potential of fine particulate matter and redox potential of the lung lining fluid

“…The individual monosaccharides demonstrated similar concentration profiles across the study locations – on average, levoglucosan dominated the profiles, contributing between 76% (in Vancouver) and 85% (in Montreal) to ∑ 3 monosaccharides, followed by mannosan (11–19%) and galactosan (4–7%). Polyols are often used as tracers of primary biogenic emission and they were previously used to probe the contribution of biogenic sources to the intrinsic OP of aerosols ( Weber et al, 2018 , Calas et al, 2019 ). In the present study, polyols (i.e.…”

Oxidative Potential Sensitivity to Metals, Br, P, S, and Se in PM10 Samples: New Insights from a Monitoring Campaign in Southeastern Italy

“…PM OP was found to contribute to oxidative stress and inflammation in cultured human lung carcinoma cells [14]. Significant variations in PM OP levels were reported in the Netherlands and Belgium [15,16], London (UK) [17], Hungary [18], Chamonix (France) [19,20], and Canada [21,22]. Daher et al [23] explained that the differences in the OP levels of PM samples are mostly related to transition metal content.…”

“…They observed, particularly during winter, a strong correlation between DTT activity and transition metals (Cr, Mn, V, Fe, Cu, Cd, and Zn) generally associated with the vehicular traffic source. Calas et al [20] reported the main findings related to the seasonal OP variations from both the DTT and AA acellular assays, as well as their correlations with PM chemical composition over a one-year period in seven French urban background sites. They also found that correlation between volume-normalized OP and metal mass concentration was strongly seasonal-, assay-, and location-dependent.…”

Overview of the French Operational Network for In Situ Observation of PM Chemical Composition and Sources in Urban Environments (CARA Program)

“…Finally, extended datasets and filter collections that have been gathered in the frame of the CARA program are already made available for complementary studies, such as comparison exercises between in situ observations and CTM outputs or remote sensing measurements (e.g., [105]), as well as cross-over studies on adverse health effects [3], [25]. Such initiatives shall be further developed in a broader landscape (e.g., including near-real time data provision to the European Copernicus Programme) while continuous online measurements at multi-sites will also set the basis for achieving long-term investigations, like epidemiological studies and air quality trend analyses.…”

“…When using high-volume samplers, large circular filters (15 cm total diameter, corresponding to a sampled surface area of about 154 cm²) are collected, so that leftover filter surfaces generally remain available after sub-sampling for completion of the analyses mentioned above. These remaining filter parts are saved in freezers, with non-analyzed filters, contributing to enlarge the wide sets of PM10 samples that can be made available for possible further analyses (e.g., for oxidative potential measurements [25], or investigation of the links between PM chemistry and microbiology, [26]).…”