Association of Biomarkers of Systemic Inflammation with Organic Components and Source Tracers in Quasi-Ultrafine Particles

• Published in: Environmental health perspectives Vol. 118; no. 6; pp. 756 - 762
• Main Authors: Delfino, Ralph J., Staimer, Norbert, Tjoa, Thomas, Arhami, Mohammad, Polidori, Andrea, Gillen, Daniel L., Kleinman, Michael T., Schauer, James J., Sioutas, Constantinos
• Format: Journal Article
• Language: English
• Published: Research Triangle Park, NC National Institute of Environmental Health Sciences 01.06.2010; US Department of Health and Human Services
• Subjects: Aerosols; Aged; Aged, 80 and over; Air pollutants; Air pollution; Analysis of Variance; Biological and medical sciences; Biological markers; Biomarkers - blood; Carbon; Chemical hazards; Coronary artery disease; Coronary heart disease; Diagnosis; Emission; Environment. Living conditions; Environmental Exposure - analysis; Exposure; Female; Health aspects; Humans; Indoor; Inflammation; Inflammation - blood; Inflammation - diagnosis; Interleukin-6 - blood; Longitudinal Studies; Los Angeles; Male; Medical sciences; Organic acids; Organic carbon; Organic pollution; Outdoor; Particle mass; Particle Size; Particulate Matter - analysis; Pollutants; Polyallylamine hydrochloride; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Public health. Hygiene; Public health. Hygiene-occupational medicine; Receptors, Tumor Necrosis Factor, Type II - blood; Risk factors; Toxicology; Tracers; Transition metals; Triterpenes - analysis; Vehicle emissions; Vehicle Emissions - analysis; United States; INE, USA, California, Los Angeles Basin; Data analysis; Cytokine; Biological marker; biomarkers of effect; Inflammation; Air; Ultrafine particle; air toxics; Epidemiology; Source; Association; Health and environment; longitudinal data analysis; cytokines; Public health; Tracers
• ISSN: 0091-6765; 1552-9924; 1552-9924
• DOI: 10.1289/ehp.0901407

Background: Evidence is needed regarding the air pollutant components and their sources responsible for associations between particle mass concentrations and human cardiovascular outcomes. We previously found associations between circulating biomarkers of inflammation and mass concentrations of quasi-ultrafme particles < 0.25 urn in aerodynamic diameter (PM₀.₂₅) in a panel cohort study of 60 elderly subjects with coronary artery disease living in the Los Angeles Basin. Objectives: We reassessed biomarker associations with PM₀.₂₅ using new particle composition data. Methods: Weekly biomarkers of inflammation were plasma interleukin-6 (IL-6) and soluble tumor necrosis factor-α receptor II (sTNF-RJI) (n = 578). Exposures included indoor and outdoor community organic PM₀.₂₅ constituents [polycyclic aromatic hydrocarbons (PAHs), hopanes, n-alkanes, organic acids, water-soluble organic carbon, and transition metals]. We analyzed the relation between biomarkers and exposures with mixed-effects models adjusted for potential confounders. Results: Indoor and outdoor PAHs (low-, medium-, and high-molecular-weight PAHs), followed by hopanes (vehicle emissions tracer), were positively associated with biomarkers, but other organic components and transition metals were not. sTNF-RII increased by 135 pg/mL [95% confidence interval (CI), 45-225 pg/mL], and IL-6 increased by 0.27 pg/mL (95% CI, 0.10-0.44 pg/mL) per interquartile range increase of 0.56 ng/m³ outdoor total PAHs. Two-pollutant models of PM0.25 with PAHs showed that nominal associations of IL-6 and sTNF-RII with PM₀.₂₅ mass were completely confounded by PAHs. Vehicular emission sources estimated from chemical mass balance models were strongly correlated with PAHs (R = 0.71). Conclusions: Traffic emission sources of organic chemicals represented by PAHs are associated with increased systemic inflammation and explain associations with quasi-ultrafme particle mass.