Hemodynamic, autonomic, and vascular effects of exposure to coarse particulate matter air pollution from a rural location

• Published in: Environmental health perspectives 2014-06, Vol.122 (6), p.624-630
• Main Authors: Brook, Robert D, Bard, Robert L, Morishita, Masako, Dvonch, J Timothy, Wang, Lu, Yang, Hui-Yu, Spino, Catherine, Mukherjee, Bhramar, Kaplan, Mariana J, Yalavarthi, Srilakshmi, Oral, Elif A, Ajluni, Nevin, Sun, Qinghua, Brook, Jeffrey R, Harkema, Jack, Rajagopalan, Sanjay
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Air Pollutants - toxicity; Air pollution; Air Pollution - statistics & numerical data; Back propagation; Blood circulation disorders; Blood pressure; Blood Pressure - drug effects; Body mass index; Cardiovascular Physiological Phenomena - drug effects; Coal-fired power plants; Cross-Over Studies; Double-Blind Method; Electrocardiography; Exposure; Female; Health; Health aspects; Health risk assessment; Health risks; Heart; Heart rate; Heart Rate - drug effects; Hemodynamics; Humans; Inhalation; Inhalation Exposure - statistics & numerical data; Male; Middle Aged; Mortality; Outdoor air quality; Particle Size; Particles; Particulate emissions; Particulate matter; Particulate Matter - toxicity; Position (location); Risk factors; Rural; Rural areas; Rural Population; Software packages; Studies; Veins & arteries; Wave velocity; Young Adult
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.1306595

Fine particulate matter (PM) air pollution is associated with numerous adverse health effects, including increased blood pressure (BP) and vascular dysfunction. Coarse PM substantially contributes to global air pollution, yet differs in characteristics from fine particles and is currently not regulated. However, the cardiovascular (CV) impacts of coarse PM exposure remain largely unknown. Our goal was to elucidate whether coarse PM, like fine PM, is itself capable of eliciting adverse CV responses. We performed a randomized double-blind crossover study in which 32 healthy adults (25.9 ± 6.6 years of age) were exposed to concentrated ambient coarse particles (CAP; 76.2 ± 51.5 μg/m(3)) in a rural location and filtered air (FA) for 2 hr. We measured CV outcomes during, immediately after, and 2 hr postexposures. Both systolic (mean difference = 0.32 mmHg; 95% CI: 0.05, 0.58; p = 0.021) and diastolic BP (0.27 mmHg; 95% CI: 0.003, 0.53; p = 0.05) linearly increased per 10 min of exposure during the inhalation of coarse CAP when compared with changes during FA exposure. Heart rate was on average higher (4.1 bpm; 95% CI: 3.06, 5.12; p < 0.0001) and the ratio of low-to-high frequency heart rate variability increased (0.24; 95% CI: 0.07, 0.41; p = 0.007) during coarse particle versus FA exposure. Other outcomes (brachial flow-mediated dilatation, microvascular reactive hyperemia index, aortic hemodynamics, pulse wave velocity) were not differentially altered by the exposures. Inhalation of coarse PM from a rural location is associated with a rapid elevation in BP and heart rate during exposure, likely due to the triggering of autonomic imbalance. These findings add mechanistic evidence supporting the biological plausibility that coarse particles could contribute to the triggering of acute CV events.