Impact of traffic-related air pollution on acute changes in cardiac autonomic modulation during rest and physical activity: a cross-over study.
People are often exposed to traffic-related air pollution (TRAP) during physical activity (PA), but it is not clear if PA modifies the impact of TRAP on cardiac autonomic modulation. We conducted a panel study among 28 healthy adults in Barcelona, Spain to examine how PA may modify the impact of TRAP on cardiac autonomic regulation. Participants completed four 2-h exposure scenarios that included either rest or intermittent exercise in high- and low-traffic environments. Time- and frequency-domain measures of heart rate variability (HRV) were monitored during each exposure period along with continuous measures of TRAP. Linear mixed-effects models were used to estimate the impact of TRAP on HRV as well as potential effect modification by PA. Exposure to TRAP was associated with consistent decreases in HRV; however, exposure-response relationships were not always linear over the broad range of exposures. For example, each 10 μg/m(3) increase in black carbon was associated with a 23% (95% CI: -31, -13) decrease in high frequency power at the low-traffic site, whereas no association was observed at the high-traffic site. PA modified the impact of TRAP on HRV at the high-traffic site and tended to weaken inverse associations with measures reflecting parasympathetic modulation (P ≤ 0.001). Evidence of effect modification at the low-traffic site was less consistent. The strength and direction of the relationship between TRAP and HRV may vary across exposure gradients. PA may modify the impact of TRAP on HRV, particularly at higher concentrations.
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
Tom
T
Cole-Hunter
Air Health Effects Science Division, Health Canada, Ottawa, Canada.
Scott
S
Weichenthal
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
Nadine
N
Kubesch
Swiss Tropical and Public Health Institute, Basel, Switzerland.
Maria
M
Foraster
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
Glòria
G
Carrasco-Turigas
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
Laura
L
Bouso
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
David
D
Martínez
Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA.
Dane
D
Westerdahl
Centre for Environmental Policy, Imperial College London, London, England.
Audrey
A
de Nazelle
Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
Mark
M
Nieuwenhuijsen
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D001336:Automobiles; D001341:Autonomic Nervous System / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D018592:Cross-Over Studies; D004784:Environmental Monitoring; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010316:Particle Size; D052638:Particulate Matter; D012146:Rest; D053260:Soot / Q000009:adverse effects; D013030:Spain; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions