2007 Progress Report: Cardiovascular Responses to Particulate ExposureEPA Grant Number: R830838
Title: Cardiovascular Responses to Particulate Exposure
Investigators: Christiani, David , Eisen, Ellen , Magari, Shannon , Schwartz, Joel
Institution: Harvard T.H. Chan School of Public Health
EPA Project Officer: Chung, Serena
Project Period: May 5, 2003 through May 4, 2006 (Extended to May 4, 2009)
Project Period Covered by this Report: May 5, 2007 through May 4,2008
Project Amount: $1,017,689
RFA: Airborne Particulate Matter Health Effects: Cardiovascular Mechanisms (2002) RFA Text | Recipients Lists
Research Category: Air , Health Effects , Particulate Matter
Objective:The overall objective of this proposal is to investigate the role of exposure to ambient airborne particulates in the development of adverse cardiovascular responses with the primary objective of identifying possible mechanisms of action. These relationships will be investigated in a community cohort living in close proximity to a large Boston bus terminal. Specific objectives include examining cardiovascular changes in healthy individuals and those with predisposing risk factors such as chronic bronchitis, chronic obstructive pulmonary disease and asthma. Serum fibrinogen and C-reactive protein levels will also be investigated in this group.
- Linear mixed-effects models were fit (both for heart rate and heart rate variability – here, 5-min SDNN); models included fixed effects for calibrated real-time fine particulate, indicator variables for the presence of a chronic health condition and smoking during the monitoring period, natural splines controlling for age, time of day and environmental factors (wind direction and temperature), and random effects for individual slopes and intercepts.
- Results were similar for various exposure averaging times and lag intervals up to two hours, although effects attenuated at averaging times above 2 hours, suggesting that the averaging time seen at higher, occupational exposure levels may be inconsistent with that seen in non-occupational cohorts.
- Potential confounders or effect modifiers (tobacco, alcohol consumption, reported use of personal or public transportation, cooking, cleaning) in models containing a fixed effect of exposure, chronic health condition, environmental factors, time of day, and age. Most factors were not important to the analysis as confounders or effect modifiers, regardless of whether a time-varying or indicator variable was used; however, time-varying cooking behavior may merit further study at intermediate exposure averaging lengths like 30-minutes to 1 hour (results were sensitive to the exposure averaging period considered).
- The effect of chronic health conditions was explored with models including factors for chronic health condition (pulmonary, cardiovascular, or both; number of conditions), specific condition, and treatment factors were fit. Results for various exposure averaging times between 5-minutes and 2-hours indicated no significant effect modification by chronic health condition. Preliminary results indicated significant modification of the effect of fine particulate on heart rate variability among those taking beta-adrenergic blocking agents, showing a 1.79 msec decrease (p=0.0119) in heart rate variability for each 10 μg/m3 of fine particulate. Preliminary results indicate that the effect of exposure to fine particulate appeared potentially to be associated with use of beta-adrenergics and statistically insignificant (p=0.87) in those not taking the drugs.
These data will be incorporated into draft manuscripts for submission to peer-reviewed journals.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
|Other project views:||All 5 publications||3 publications in selected types||All 3 journal articles|
||Kim JY, Prouty LA, Fang SC, Rodrigues EG, Magari SR, Modest GA, Christiani DC. Association between fine particulate matter and oxidative DNA damage may be modified in individuals with hypertension. Journal of Occupational and Environmental Medicine 2009;51(10):1158-1166.||
||Lee MS, Eum KD, Fang SC, Rodrigues EG, Modest GA, Christiani DC. Oxidative stress and systemic inflammation as modifiers of cardiac autonomic responses to particulate air pollution. International Journal of Cardiology 2014;176(1):166-170.||
||Lee MS, Eum KD, Rodrigues EG, Magari SR, Fang SC, Modest GA, Christiani DC. Effects of personal exposure to ambient fine particulate matter on acute change in nocturnal heart rate variability in subjects without overt heart disease. American Journal of Cardiology 2016;117(1):151-156.||