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

作者：Delfino Ralph J^*; Staimer Norbert; Tjoa Thomas; Arhami Mohammad; Polidori Andrea; Gillen Daniel L; George Steven C; Shafer Martin M; Schauer James J; Sioutas Constantinos

来源：Epidemiology, 2010, 21(6): 892-902.

DOI：10.1097/EDE.0b013e3181f20e6c

Background: Exposure-response information about particulate air-pollution constituents is needed to protect sensitive populations. Particulate matter <2.5 mm (PM(2.5)) 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). PM(2.5) mass fractions were PM(0.25) (<0.25 mu m) and PM(0.25-2.5) (0.25-2.5 mu m). Primary organic markers included PM(2.5) primary organic carbon, and PM(0.25) polycyclic aromatic hydrocarbons and hopanes. Secondary organic markers included PM(2.5) secondary organic carbon, and PM(0.25) water soluble organic carbon and n-alkanoic acids. Gaseous pollutants included carbon monoxide (CO) and nitrogen oxides (NO(x); combustion emissions markers), and ozone (O(3); photochemistry marker). To assess PM oxidative potential, we exposed rat alveolar macrophages in vitro to aqueous extracts of PM(0.25) filters and measured reactive-oxygen-species production. Biomarker associations with exposures were evaluated with mixed-effects models.
Results: Secondary organic markers, PM(0.25-2.5), and O(3) were positively associated with exhaled NO. Primary organic markers, PM(0.25), CO, and NO x 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.

• 出版日期2010-11