@article {18185,
	title = {A controlled trial of acute effects of human exposure to traffic particles on pulmonary oxidative stress and heart rate variability},
	journal = {Particle and Fibre Toxicology},
	volume = {11},
	year = {2014},
	note = {Laumbach, Robert JKipen, Howard MKo, SusanKelly-McNeil, KathieCepeda, ClarimelPettit, AshleyOhman-Strickland, PamelaZhang, LinZhang, JunfengGong, JichengVeleeparambil, ManojGow, Andrew JengR01 HL086621/HL/NHLBI NIH HHS/T32 ES007148/ES/NIEHS NIH HHS/P30 ES005022/ES/NIEHS NIH HHS/P30 ES013508/ES/NIEHS NIH HHS/ES005022/ES/NIEHS NIH HHS/T32ES007148/ES/NIEHS NIH HHS/Clinical TrialRandomized Controlled TrialResearch Support, N.I.H., ExtramuralEnglandPart Fibre Toxicol. 2014 Nov 1;11:45. doi: 10.1186/s12989-014-0045-5.},
	month = {Nov 1},
	pages = {45},
	edition = {2014/11/02},
	abstract = {BACKGROUND: For many individuals, daily commuting activities on roadways account for a substantial proportion of total exposure, as well as peak-level exposures, to traffic-related air pollutants (TRAPS) including ultrafine particles, but the health impacts of these exposures are not well-understood. We sought to determine if exposure to TRAPs particles during commuting causes acute oxidative stress in the respiratory tract or changes in heart rate variability (HRV), a measure of autonomic activity. METHODS: We conducted a randomized, cross-over trial in which twenty-one young adults took two 1.5-hr rides in a passenger vehicle in morning rush-hour traffic. The subjects wore a powered-air-purifying respirator, and were blinded to high-efficiency particulate air (HEPA) filtration during one of the rides. At time points before and after the rides, we measured HRV and markers of oxidative stress in exhaled breath condensate (EBC) including nitrite, the sum of nitrite and nitrate, malondialdehyde, and 8-isoprostane. We used mixed linear models to evaluate the effect of exposure on EBC and HRV outcomes, adjusting for pre-exposure response levels. We used linear models to examine the effects of particle concentrations on EBC outcomes at post-exposure time points. RESULTS: Mean EBC nitrite and the sum of nitrite and nitrate were increased from baseline at immediately post-exposure comparing unfiltered to filtered rides (2.11 muM vs 1.70 muM, p = 0.02 and 19.1 muM vs 10.0 muM, p = 0.02, respectively). Mean EBC malondialdehyde (MDA) concentrations were about 10\% greater following the unfiltered vs. filtered exposures, although this result was not statistically significant. We found no significant associations between exposure to traffic particles and HRV outcomes at any of the time points. At immediately post-exposure, an interquartile range increase in particle number concentration was associated with statistically significant increases in nitrite (99.4\%, 95\% CI 32.1\% to 166.7\%) and nitrite + nitrate (75.7\%, 95\% CI 21.5\% to 130.0\%). CONCLUSIONS: Increases in markers of oxidative stress in EBC may represent early biological responses to widespread exposures to TRAPs particles that affect passengers in vehicles on heavily trafficked roadways.},
	keywords = {Adolescent, Adult, Air Pollutants/chemistry/*toxicity, Arrhythmias, Cardiac/*chemically induced/metabolism, Biomarkers/metabolism, Breath Tests, Cross-Over Studies, Female, Heart Rate/drug effects, Humans, Inhalation Exposure/*adverse effects, Lung/drug effects/metabolism, Male, Motor Vehicles, New Jersey, Nitrates/metabolism, Nitrites/metabolism, Oxidative Stress/*drug effects, Particulate Matter/administration \& dosage/chemistry/*toxicity, Respiratory Mucosa/*drug effects/metabolism, Single-Blind Method, Vehicle Emissions/*toxicity, Young Adult},
	isbn = {1743-8977 (Electronic)1743-8977 (Linking)},
	author = {Laumbach, R. J. and Kipen, H. M. and Ko, S. and Kelly-McNeil, K. and Cepeda, C. and Pettit, A. and Ohman-Strickland, P. and L. Zhang and J. Zhang and Gong, J. and Veleeparambil, M. and Gow, A. J.}
}
