Effects of ambient coarse, fine, and ultrafine particles and their biological constituents on systemic biomarkers: a controlled human exposure study
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 O3, 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.
History
Publication title
Environmental Health PerspectivesVolume
123Issue
6Pagination
534-540ISSN
0091-6765Department/School
Menzies Institute for Medical ResearchPublisher
Us Dept Health Human Sciences Public Health SciencePlace of publication
Natl Inst Health, Natl Inst Environmental Health Sciences, Po Box 12233, Res Triangle Pk, USA, Nc, 27709-2233Rights statement
Reproduced with permission from Environmental Health PerspectivesRepository Status
- Open