Reactive Oxygen Species Generation Linked to Sources of Atmospheric Particulate Matter and Cardiorespiratory Effects

Abstract

Exposure to atmospheric fine particulate matter (PM2.5) is associated with cardiorespiratory morbidity and mortality, but the mechanisms are not well understood. We assess the hypothesis that PM2.5 induces oxidative stress in the body via catalytic generation of reactive oxygen species (ROS). A dithiothreitol (DTT) assay was used to measure the ROS-generation potential of water-soluble PM2.5. Source apportionment on ambient (Atlanta, GA) PM2.5 was performed using the chemical mass balance method with ensemble-averaged source impact profiles. Linear regression analysis was used to relate PM2.5 emission sources to ROS-generation potential and to estimate historical levels of DTT activity for use in an epidemiologic analysis for the period of 1998-2009. Light-duty gasoline vehicles (LDGV) exhibited the highest intrinsic DTT activity, followed by biomass burning (BURN) and heavy-duty diesel vehicles (HDDV) (0.11 ± 0.02, 0.069 ± 0.02, and 0.052 ± 0.01 nmol min(-1) μg(-1)source, respectively). BURN contributed the largest fraction to total DTT activity over the study period, followed by LDGV and HDDV (45, 20, and 14%, respectively). DTT activity was more strongly associated with emergency department visits for asthma/wheezing and congestive heart failure than PM2.5. This work provides further epidemiologic evidence of a biologically plausible mechanism, that of oxidative stress, for associations of adverse health outcomes with PM2.5 mass and supports continued assessment of the utility of the DTT activity assay as a measure of ROS-generating potential of particles.

In vitro Evaluation of Oxidative Stress Caused by Fine Particles (PM2.5) Exhausted from Heavy-Duty Vehicles Using Diesel/Biodiesel Blends under Real World Conditions

“…So far, we have not found reported DTT loss rate values for diesel/biodiesel exhausted particles. However, as it can be observed from Table 5, other studies used similar particle 24 and the reported results from Verma et al, 35 and McWhinney et al 50 (also see Figure 3). We can also conclude oxidative potential of particles emitted from the burning of diesel/biodiesel blends is comparable to fossil diesel-emitted particles.…”

“…However, it is still uncertain if biodiesel-exhausted particles (BEP) would be more or less toxic than DEP. Despite the fact some studies have tried to address this issue, 4,16,17,23,24 the toxicity of traffic-related urban PM is still not completely understood and more studies are needed.…”

“…6,29,30 ROS may either be primarily transported on particles and/or be catalytically generated by other particle components through redox chemistry producing healthrelated issues. 24,25 For instance, some transition metals (such as Fe and Cu) and organic species (e.g. polycyclic aromatic compounds and quinones or quinone-like compounds) as well as humic-like substances (HULIS), black and brown carbon (BC and BrC) within PM are known to increase the production of ROS either in vitro or in vivo, especially if they are present in fine and ultrafine size range, [4][5][6]24,[30][31][32][33][34][35] since they are able to go more profoundly in the respiratory system.…”

“…24,25 For instance, some transition metals (such as Fe and Cu) and organic species (e.g. polycyclic aromatic compounds and quinones or quinone-like compounds) as well as humic-like substances (HULIS), black and brown carbon (BC and BrC) within PM are known to increase the production of ROS either in vitro or in vivo, especially if they are present in fine and ultrafine size range, [4][5][6]24,[30][31][32][33][34][35] since they are able to go more profoundly in the respiratory system. Meanwhile, considering diesel/biodiesel blends exhausts are substantially composed by ever small size PM, such as nanoparticles and/or ultrafine particles rich in semi-volatile organic compounds and trace metals, 1,7,16 it is likely ROS may be contributing to the adverse health effects caused by DEP or even BEP.…”

An apportionment method for the Oxydative Potential to the atmospheric PM sources: application to a one-year study in Chamonix, France

“…Previous studies (Bates et al, 2015;Fang et al, 2016;Verma et al, 2014) also highlighted the importance of this source to explain the OP AA and DTT. We may explain such high intrinsic OP by the presence of metals in this source -notably the copper (Charrier et al, 2015).…”