Background: Ambient coarse, fine, and ultrafine particles have been associated with mortality and morbidity. Few studies have compared how various particle size fractions affect systemic biomarkers.

Objectives: We examined changes of blood and urinary biomarkers following exposures to three particle sizes.

Methods: Fifty healthy nonsmoking volunteers, mean age of 28 years, were exposed to coarse (2.5–10 μm; mean, 213 μg/m³) and fine (0.15–2.5 μm; mean, 238 μg/m³) concentrated ambient particles (CAPs), and filtered ambient and/or medical air. Twenty-five participants were exposed to ultrafine CAP (< 0.3 μm; mean, 136 μg/m³) and filtered medical air. Exposures lasted 130 min, separated by ≥ 2 weeks. Blood/urine samples were collected preexposure and 1 hr and 21 hr postexposure to determine blood interleukin-6 and C-reactive protein (inflammation), endothelin-1 and vascular endothelial growth factor (VEGF; vascular mediators), and malondialdehyde (lipid peroxidation); as well as urinary VEGF, 8-hydroxy-deoxy-guanosine (DNA oxidation), and malondialdehyde. Mixed-model regressions assessed pre- and postexposure differences.

Results: One hour postexposure, for every 100-μg/m³ increase, coarse CAP was associated with increased blood VEGF (2.41 pg/mL; 95% CI: 0.41, 4.40) in models adjusted for O_3, fine CAP with increased urinary malondialdehyde in single- (0.31 nmol/mg creatinine; 95% CI: 0.02, 0.60) and two-pollutant models, and ultrafine CAP with increased urinary 8-hydroxydeoxyguanosine in single- (0.69 ng/mg creatinine; 95% CI: 0.09, 1.29) and two-pollutant models, lasting < 21 hr. Endotoxin was significantly associated with biomarker changes similar to those found with CAPs.

Conclusions: Ambient particles with various sizes/constituents may influence systemic biomarkers differently. Endotoxin in ambient particles may contribute to vascular mediator changes and oxidative stress.

Citation: Liu L, Urch B, Poon R, Szyszkowicz M, Speck M, Gold DR, Wheeler AJ, Scott JA, Brook JR, Thorne PS, Silverman FS. 2015. Effects of ambient coarse, fine, and ultrafine particles and their biological constituents on systemic biomarkers: a controlled human exposure study. Environ Health Perspect 123:534–540;  http://dx.doi.org/10.1289/ehp.1408387

Address correspondence to L. Liu, Health Canada, A.L. 1907A, 200 Eglantine Driveway, Ottawa, Ontario, Canada K1A 0K9. Telephone: (613) 410-2502. E-mail: ling.liu@hc-sc.gc.ca

We thank the staff at the Gage for their technical work on controlled exposures and M. Rigden and K.L. Ku at Health Canada for their work on biomarkers.

The study was funded by Health Canada’s Clean Air Regulatory Agenda, the U.S. Environmental Protection Agency (RD-83241601), Environment Canada, and AllerGen NCE Inc. Infrastructure for concentrated ambient particle exposure facility was provided by SOCAAR (the Southern Ontario Centre for Atmospheric Aerosol Research) through funding from the Canada Foundation for Innovation.

The contents of this publication are solely the responsibility of the grantee and do not necessarily represent the official views of the funding agencies. The funding agencies do not endorse the purchase of any commercial products or services mentioned in the publication.

The authors declare they have no actual or potential competing financial interests.

Received: 7 March 2014 Accepted: 14 January 2015 Advance Publication: 16 January 2015 Final Publication: 1 June 2015