TY - JOUR
T1 - ECG parameters and exposure to carbon ultrafine particles in young healthy subjects
AU - Zareba, Wojciech
AU - Couderc, Jean Philippe
AU - Oberdorster, Gunter
AU - Chalupa, David
AU - Cox, Christopher
AU - Huang, Li Shan
AU - Peters, Annette
AU - Utell, Mark J.
AU - Frampton, Mark W.
N1 - Funding Information:
Received 3 July 2008; accepted 13 September 2008. This study was supported by grants R01ES13394, P30ES01247, and RR00044 from the National Institutes of Health, assistance agreement RD 832415 from the US Environmental Protection Agency, and contract 98-19 from the Health Effects Institute. Research described in this article was conducted under contract to the Health Effects Institute (HEI), an organization jointly funded by the US Environmental Protection Agency (EPA) (assistance agreement X-812059) and automotive manufacturers. The contents of this article do not necessarily reflect the views of the HEI, nor do they necessarily reflect the policies of the US EPA or of automotive manufacturers. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. Address correspondence to Mark W. Frampton, MD, Pulmonary and Critical Care, University of Rochester Medical Center, Box 692, Rochester, NY 14642, USA. E-mail: mark frampton@urmc.rochester.edu
PY - 2009/2
Y1 - 2009/2
N2 - The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 μg/m3 (∼2 × 106 particles/cm3, count median diameter ∼25 nm, geometric standard deviation ∼1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 μg/m3 UFP (∼7 × 106 particles/cm3), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10-25 μg/m3 ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium.
AB - The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 μg/m3 (∼2 × 106 particles/cm3, count median diameter ∼25 nm, geometric standard deviation ∼1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 μg/m3 UFP (∼7 × 106 particles/cm3), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10-25 μg/m3 ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium.
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U2 - 10.1080/08958370802492407
DO - 10.1080/08958370802492407
M3 - Article
C2 - 18991063
AN - SCOPUS:60749133801
SN - 0895-8378
VL - 21
SP - 223
EP - 233
JO - Inhalation Toxicology
JF - Inhalation Toxicology
IS - 3
ER -