Baccarelli, AndreaBarretta, FrancescoDou, ChangZhang, XiaoMcCracken, John PatrickDíaz, AnaitéBertazzi, Pier AlbertoSchwartz, JoelWang, ShengHou, Lifang2012-04-132011Baccarelli, Andrea, Francesco Barretta, Chang Dou, Xiao Zhang, John Patrick McCracken, Anaité Díaz, Pier Alberto Bertazzi, Joel David Schwartz, Sheng Wang, and Lifang Hou. 2011. Effects of particulate air pollution on blood pressure in a highly exposed population in Beijing, China: A repeated-measure study. Environmental Health 10(1):108.1476-069Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:8579870Background: Particulate Matter (PM) exposure is critical in Beijing due to high population density and rapid increase in vehicular traffic. PM effects on blood pressure (BP) have been investigated as a mechanism mediating cardiovascular risks, but results are still inconsistent. The purpose of our study is to determine the effects of ambient and personal PM exposure on BP. Methods: Before the 2008 Olympic Games (June 15-July 27), we examined 60 truck drivers and 60 office workers on two days, 1-2 weeks apart (n = 240). We obtained standardized measures of post-work BP. Exposure assessment included personal \(PM_{2.5}\) and Elemental Carbon (EC, a tracer of traffic particles) measured using portable monitors during work hours; and ambient \(PM_{10}\) averaged over 1-8 days pre-examination. We examined associations of exposures (exposure group, personal \(PM_{2.5}/EC\), ambient \(PM_{10}\)) with BP controlling for multiple covariates. Results: Mean personal \(PM_{2.5}\) was \(94.6 μg/m^3\) (SD = 64.9) in office workers and 126.8 (SD = 68.8) in truck drivers (p-value < 0.001). In all participants combined, a \(10 μg/m^3\) increase in 8-day ambient \(PM_{10}\) was associated with BP increments of 0.98 (95%CI 0.34; 1.61; p-value = 0.003), 0.71 (95%CI 0.18; 1.24; p-value = 0.01), and 0.81 (95%CI 0.31; 1.30; p-value = 0.002) mmHg for systolic, diastolic, and mean BP, respectively. BP was not significantly different between the two groups (p-value > 0.14). Personal \(PM_{2.5}\) and EC during work hours were not associated with increased BP. Conclusions: Our results indicate delayed effects of ambient \(PM_{10}\) on BP. Lack of associations with exposure groups and personal \(PM_{2.5}/EC\) indicates that PM effects are related to background levels of pollution in Beijing, and not specifically to work-related exposure.en-USparticulate matterpersonal monitoringblood pressuretraffic pollutionChinaJournal Article2012-04-1310.1186/1476-069X-10-108