Impact of personal and ambient-level exposures to nitrogen dioxide and particulate matter on cardiovascular function

This work explored the association between nitrogen dioxide (NO₂) and PM_2.5 components with changes in cardiovascular function in an adult non-smoking cohort. The cohort consisted of 65 volunteers participating in the US EPA's Detroit Exposure and Aerosol Research Study (DEARS) and a University of Michigan cardiovascular sub-study. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), brachial artery diameter (BAD), brachial artery flow-mediated dilatation (FMD) and nitroglycerin-mediated arterial dilatation (NMD) were collected by in-home examinations. A maximum of 336 daily environmental and health effect observations were obtained. Daily potassium air concentrations were associated with significant decreases in DBP (−0.0447 mmHg/ng/m³ ± 0.0132, p = 0.0016, lag day 0) among participants compliant with the personal monitoring protocol. Personal NO₂ exposures resulted in significant changes in BAD (e.g., 0.0041 mm/ppb ± 0.0019, p = 0.0353, lag day 1) and FMD (0.0612 ± 0.0235, p = 0.0103, lag day 0) among other findings.

Keywords:

• air pollutant concentrations
• exposure assessment
• particulate matter
• epidemiology

Acknowledgments

The US Environmental Protection Agency through its Office of Research and Development funded and conducted the research described here under contract 68-D-00-012 (RTI International), EP-D-04-068 (Battelle Columbus Laboratory), 68-D-00-206 and EP-05-D-065 (Alion Science and Technology). It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. This study was also supported by the Electric Power Research Institute (Contract EP-P15887/C7915) and from a National Institutes of Health General Clinical Research Center Grant: M01-RR000042. Dennis Williams and Robert Kellogg of Alion Science and Technology are acknowledged for their technical contributions in NO₂ or PM_2.5 component analyses. Gary Norris and Rachelle Duvall (US EPA) kindly provided the discussion concerning possible sources of ambient potassium. Carry Croghan and Alan Vette (US EPA) assisted in exposure data tabulation. Charles Rodes and Jonathan Thornburg along with the field staff of RTI International were responsible for performing the field data collections.