Department of Building Science, School of Architecture, Tsinghua University, Beijing, China.
Epidemiology. 2012 Nov;23(6):870-8. doi: 10.1097/EDE.0b013e31826b800e.
Seasonal and regional differences have been reported for the increase in short-term mortality associated with a given increase in the concentration of outdoor particulate matter with an aerodynamic diameter smaller than 10 μm (PM(10) mortality coefficient). Some of this difference may be because of seasonal and regional differences in indoor exposure to PM(10) of outdoor origin.
From a previous study, we obtained PM(10) mortality coefficients for each season in seven U.S. regions. We then estimated the change in the sum of indoor and outdoor PM(10) exposure per unit change in outdoor PM(10) exposure (PM(10) exposure coefficient) for each season in each region. This was originally accomplished by estimating PM(10) exposure coefficients for 19 cities within the regions for which we had modeled building infiltration rates. We subsequently expanded the analysis to include 64 additional cities with less well-characterized building infiltration rates.
The correlation (r = 0.71 [95% confidence interval = 0.46 to 0.86]) between PM(10) mortality coefficients and PM(10) exposure coefficients (28 data pairs; four seasons in each of seven regions) was strong using exposure coefficients derived from the originally targeted 19 National Morbidity, Mortality, and Air Pollutions Study cities within the regions. The correlation remained strong (r = 0.67 [0.40 to 0.84]) when PM(10) exposure coefficients were derived using 83 cities within the regions (the original 19 plus the additional 64).
Seasonal and regional differences in PM(10) mortality coefficients appear to partially reflect seasonal and regional differences in total PM(10) exposure per unit change in outdoor exposure.
据报道，与室外粒径小于 10μm 的颗粒物（PM（10）浓度增加相关的短期死亡率呈季节性和区域性差异。PM（10）死亡率系数）。这种差异的部分原因可能是由于室内和室外来源的 PM（10）暴露的季节性和区域性差异。
我们从之前的一项研究中获得了美国七个地区每个季节的 PM（10）死亡率系数。然后，我们估算了每个季节每个地区的室外 PM（10）暴露每单位变化的室内和室外 PM（10）暴露总和的变化（PM（10）暴露系数）。这是通过估计我们对有建模建筑物渗透率的地区内的 19 个城市的 PM（10）暴露系数来完成的。随后，我们将分析扩展到包括渗透率特征较差的 64 个其他城市。
PM（10）死亡率系数与 PM（10）暴露系数之间的相关性（r = 0.71 [95％置信区间= 0.46 至 0.86]）很强，使用最初针对该地区的 19 个国家发病率，死亡率和空气污染研究城市得出的 PM（10）暴露系数。当使用该地区内的 83 个城市（原始的 19 个加上另外的 64 个）得出 PM（10）暴露系数时，相关性仍然很强（r = 0.67 [0.40 至 0.84]）。
PM（10）死亡率系数的季节性和区域性差异似乎部分反映了总 PM（10）暴露的季节性和区域性差异，每单位室外暴露变化。
