Park Sung Kyun, O'Neill Marie S, Stunder Barbara J B, Vokonas Pantel S, Sparrow David, Koutrakis Petros, Schwartz Joel
Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
J Expo Sci Environ Epidemiol. 2007 Aug;17(5):488-97. doi: 10.1038/sj.jes.7500552. Epub 2007 Feb 14.
Although many studies report that exposure to air pollution harms health, few have examined associations between pollution sources and health outcomes. We hypothesized that pollution originating in different locations has different associations with heart rate variability (HRV) among 497 men from the Normative Aging Study in Boston, Massachusetts. We identified the paths that air masses traveled ('back-trajectories') before arriving in Boston on the days the men were examined. Next, we classified these trajectories into six clusters. We examined whether the association of measured air pollutants with HRV (standard deviation of normal-to-normal intervals, high-frequency power (HF) and low-frequency power (LF), and LF/HF ratio) differed by cluster. We also examined whether the clusters alone (not considering air pollution measurements) showed different associations with HRV. The effects of black carbon (BC) on all HRV measures were strongest on days with southwest trajectories. Subjects who were examined on days where air parcels came from west had the strongest associations with ozone. All particle pollutants (particulate matter <2.5 microm in aerodynamic diameter (PM2.5), BC, and sulfates) were associated with increased LF/HF ratio on days with relatively short trajectories, which are related to local, slow-moving air masses. We also observed significant increases in LF/HF in days where air came from the northwest and west, compared to north trajectory days. Health effects associated with exposure to air pollution can be evaluated using pollutant concentrations as well as aspects of the pollution mixture captured by identifying locations where air masses originate. Independent effects of both these indicators of pollution exposure were seen on cardiac autonomic function.
尽管许多研究报告称，接触空气污染会损害健康，但很少有研究考察污染源与健康结果之间的关联。我们推测，对于来自马萨诸塞州波士顿规范衰老研究中的497名男性，不同来源的污染与心率变异性（HRV）之间存在不同的关联。我们确定了这些男性接受检查当天气团到达波士顿之前所经过的路径（“后向轨迹”）。接下来，我们将这些轨迹分为六个类别。我们考察了测量的空气污染物与HRV（正常到正常间期的标准差、高频功率（HF）和低频功率（LF）以及LF/HF比值）之间的关联是否因类别而异。我们还考察了这些类别本身（不考虑空气污染测量结果）与HRV之间是否存在不同的关联。黑碳（BC）对所有HRV指标的影响在西南轨迹的日子里最为强烈。在气团来自西部的日子接受检查的受试者与臭氧的关联最强。在与本地缓慢移动气团相关的较短轨迹的日子里，所有颗粒污染物（空气动力学直径小于2.5微米的颗粒物（PM2.5）、BC和硫酸盐）都与LF/HF比值升高有关。与来自北方轨迹的日子相比，我们还观察到在气团来自西北和西部的日子里LF/HF有显著增加。与接触空气污染相关的健康影响可以通过污染物浓度以及通过确定气团来源地所捕捉到的污染混合物的特征来评估。污染暴露的这两个指标对心脏自主功能均有独立影响。
