Title: | Traffic-related air pollution and acute changes in heart rate variability and respiratory function in urban cyclists |
Author(s): | Weichenthal S; Kulka R; Dubeau A; Martin C; Wang D; Dales R; |
Address: | "Air Health Sciences Division, Health Canada, Ottawa, Canada. scott.weichenthal@hc-sc.gc.ca" |
ISSN/ISBN: | 1552-9924 (Electronic) 0091-6765 (Print) 0091-6765 (Linking) |
Abstract: | "BACKGROUND: Few studies have examined the acute health effects of air pollution exposures experienced while cycling in traffic. OBJECTIVES: We conducted a crossover study to examine the relationship between traffic pollution and acute changes in heart rate variability. We also collected spirometry and exhaled nitric oxide measures. METHODS: Forty-two healthy adults cycled for 1 hr on high- and low-traffic routes as well as indoors. Health measures were collected before cycling and 1-4 hr after the start of cycling. Ultrafine particles (UFPs; = 0.1 mum in aerodynamic diameter), particulate matter = 2.5 mum in aerodynamic diameter (PM2.5), black carbon, and volatile organic compounds were measured along each cycling route, and ambient nitrogen dioxide (NO2) and ozone (O3) levels were recorded from a fixed-site monitor. Mixed-effects models were used to estimate associations between air pollutants and changes in health outcome measures relative to precycling baseline values. RESULTS: An interquartile range increase in UFP levels (18,200/cm3) was associated with a significant decrease in high-frequency power 4 hr after the start of cycling [beta = -224 msec2; 95% confidence interval (CI), -386 to -63 msec2]. Ambient NO2 levels were inversely associated with the standard deviation of normal-to-normal (NN) intervals (beta = -10 msec; 95% CI, -20 to -0.34 msec) and positively associated with the ratio of low-frequency to high-frequency power (beta = 1.4; 95% CI, 0.35 to 2.5) 2 hr after the start of cycling. We also observed significant inverse associations between ambient O3 levels and the root mean square of successive differences in adjacent NN intervals 3 hr after the start of cycling. CONCLUSIONS: Short-term exposures to traffic pollution may contribute to altered autonomic modulation of the heart in the hours immediately after cycling" |
Keywords: | Adult Air Pollution/*adverse effects Cross-Over Studies Environmental Monitoring Female Forced Expiratory Volume/drug effects Heart Rate/*drug effects Humans Male Maximal Midexpiratory Flow Rate/drug effects Middle Aged Nitrogen Dioxide/toxicity Ozone/tox; |
Notes: | "MedlineWeichenthal, Scott Kulka, Ryan Dubeau, Aimee Martin, Christina Wang, Daniel Dales, Robert eng Clinical Trial 2011/06/16 Environ Health Perspect. 2011 Oct; 119(10):1373-8. doi: 10.1289/ehp.1003321. Epub 2011 Jun 14" |