Associations of Primary and Secondary Organic Aerosols With Airway and Systemic Inflammation in an Elderly Panel Cohort

Abstract

Background Exposure-response information about particulate air-pollution constituents is needed to protect sensitive populations. Particulate matter <2.5 mm (PM2.5) components may induce oxidative stress through reactive-oxygen-species generation, including primary organics from combustion sources and secondary organics from photochemically oxidized volatile organic compounds. We evaluated differences in airway versus systemic inflammatory responses to primary versus secondary organic particle components, particle size fractions, and the potential of particles to induce cellular production of reactive oxygen species. Methods A total of 60 elderly subjects contributed up to 12 weekly measurements of fractional exhaled nitric oxide (NO; airway inflammation biomarker), and plasma interleukin-6 (IL-6; systemic inflammation biomarker). PM2.5 mass fractions were PM0.25 (<0.25 µm) and PM0.25–2.5 (0.25–2.5 µm). Primary organic markers included PM2.5 primary organic carbon, and PM0.25 polycyclic aromatic hydrocarbons and hopanes. Secondary organic markers included PM2.5 secondary organic carbon, and PM0.25 water soluble organic carbon and n-alkanoic acids. Gaseous pollutants included carbon monoxide (CO) and nitrogen oxides (NOx; combustion emissions markers), and ozone (O3; photochemistry marker). To assess PM oxidative potential, we exposed rat alveolar macrophages in vitro to aqueous extracts of PM0.25 filters and measured reactive-oxygen-species production. Biomarker associations with exposures were evaluated with mixed-effects models. Results Secondary organic markers, PM0.25–2.5, and O3 were positively associated with exhaled NO. Primary organic markers, PM0.25, CO, and NOx were positively associated with IL-6. Reactive oxygen species were associated with both outcomes. Conclusions Particle effects on airway versus systemic inflammation differ by composition, but overall particle potential to induce generation of cellular reactive oxygen species is related to both outcomes.

A rapid assessment of the impact of hazard reduction burning around Sydney, May 2016

“…For average exposures of 273 ng/m 3 -that is, occupational exposures considerably higher that environmental levels -the RR was 1.64 (95% CI: 1.13-2.38). PAHs were also associated with increased systemic inflammation, which explained the association with quasiultrafine particle mass from traffic emission sources, more so that other organic components of PM (Delfino et al, 2010b). Another study found an association between PM, particle-bound organic compounds (including PAHs) and adverse health symptoms in survivors of myocardial infarctions (Kraus et al, 2011).…”

“…A series of panel studies have reported that while total organic carbon has not been associated with the outcomes, associations have been observed for primary organic carbon (and not secondary organic carbon compounds) (Delfino et al, 2009b;. In one study, primary organic carbon was associated with markers for systemic inflammation, whereas secondary organic carbon was associated with a marker for pulmonary inflammation (Delfino et al, 2010b).…”

“…Airway inflammation has also been examined in a number of panel studies, using exhaled nitric oxide as a non-invasive measure of allergic inflammation. While there appears to be a clear relationship between ozone and health effects in children (Liu et al, 2009;Berhane et al, 2011;Nickmilder et al, 2007;Barraza-Villarreal et al, 2008;Sienra-Monge et al, 2004), the data for adults is mixed (Delfino et al, 2010b;Eiswerth, Douglass Shaw & Yen, 2005). There is little evidence from panel studies to demonstrate this association is stronger in asthmatic children (Berhane et al, 2011;BarrazaVillarreal et al, 2008).…”

Air Pollution, Reactive Oxygen Species (ROS), and Autonomic Nervous System Interactions Modulate Cardiac Oxidative Stress and Electrophysiological Changes

“…Primary particles, organic markers, ultrafine particles, CO, and NO x were positively associated with IL-6. Reactive oxygen species were associated with both outcomes [Delfino et al, 2010].…”

Commuting in Los Angeles: Cancer and Non-cancer Health Risks of Roadway, Light-Rail and Subway Transit Routes

“…Tel. : 1-213-740-6134;Fax: 1-213-744-1426 E-mail address: sioutas@usc.edu size allowing for deep penetration into the lungs and subsequently the bloodstream (Brugge et al, 2007;de Kok et al, 2006;Delfino et al, 2010). PM 2.5 is composed of several chemical species, including carbonaceous materials such as elemental and organic carbon (EC/OC), crustal elements, organic compounds, transition metals, hopanes and steranes, and vehicular abrasion detritus.…”