Acute increase in blood pressure during inhalation of coarse particulate matter air pollution from an urban location

Particulate matter (PM) air pollution is a leading global risk factor for cardiovascular mortality. Although exposure to fine PM <2.5 μm raises arterial blood pressure (BP), few studies have evaluated the impact of coarse PM which differs in size (2.5-10 μm), sources, and chemistry. Twenty-nine healthy adults (30.4 ± 8.2 years) underwent a randomized double-blind crossover study involving 2-hour exposures to concentrated ambient coarse PM (164.2 ± 80.4 μg/m3) at an urban location (Dearborn, Michigan) versus filtered air. Cardiovascular outcomes were measured during, immediately, and 2 hours after exposures. Both systolic (1.9 mm Hg; 95% confidence interval: 0.96, 2.8; P < .001) and diastolic (1.9 mm Hg; 95% confidence interval: 1.1, 2.7; P < .001) BP levels were higher throughout coarse PM compared with filtered air exposures by mixed-model analyses. Heart rate variability, endothelial function, and arterial compliance were not significantly affected. Brief exposure to coarse PM in an urban environment raises arterial BP. These findings add mechanistic support to the contention that coarse PM may be capable of promoting cardiovascular events.