Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
Environ Health Perspect. 2012 Jun;120(6):824-30. doi: 10.1289/ehp.1104447. Epub 2012 Feb 22.
Epidemiologic studies of fine particulate matter [aerodynamic diameter ≤ 2.5 μm (PM(2.5))] typically use outdoor concentrations as exposure surrogates. Failure to account for variation in residential infiltration efficiencies (F(inf)) will affect epidemiologic study results.
We aimed to develop models to predict F(inf) for > 6,000 homes in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study of PM(2.5) exposure, subclinical cardiovascular disease, and clinical outcomes.
We collected 526 two-week, paired indoor-outdoor PM(2.5) filter samples from a subset of study homes. PM(2.5) elemental composition was measured by X-ray fluorescence, and F(inf) was estimated as the indoor/outdoor sulfur ratio. We regressed F(inf) on meteorologic variables and questionnaire-based predictors in season-specific models. Models were evaluated using the R² and root mean square error (RMSE) from a 10-fold cross-validation.
The mean ± SD F(inf) across all communities and seasons was 0.62 ± 0.21, and community-specific means ranged from 0.47 ± 0.15 in Winston-Salem, North Carolina, to 0.82 ± 0.14 in New York, New York. F(inf) was generally greater during the warm (> 18°C) season. Central air conditioning (AC) use, frequency of AC use, and window opening frequency were the most important predictors during the warm season; outdoor temperature and forced-air heat were the best cold-season predictors. The models predicted 60% of the variance in 2-week F(inf), with an RMSE of 0.13.
We developed intuitive models that can predict F(inf) using easily obtained variables. Using these models, MESA Air will be the first large epidemiologic study to incorporate variation in residential F(inf) into an exposure assessment.
细颗粒物（[空气动力学直径≤2.5μm（PM(2.5))]）的流行病学研究通常使用室外浓度作为暴露替代物。未能考虑住宅渗透率（F(inf)）的变化将影响流行病学研究结果。
我们旨在为多民族动脉粥样硬化与空气污染研究（MESA Air）中的 6000 多个家庭开发模型，该研究是一项关于 PM(2.5)暴露、亚临床心血管疾病和临床结局的前瞻性队列研究。
我们从研究家庭的子集中收集了 526 对为期两周的室内外 PM(2.5)过滤器样本。PM(2.5)的元素组成通过 X 射线荧光进行测量，渗透率（F(inf)）则通过室内/室外硫比来估计。我们根据气象变量和基于问卷的预测因素在季节特定模型中对 F(inf)进行回归。通过 10 折交叉验证的 R²和均方根误差（RMSE）来评估模型。
所有社区和季节的平均 F(inf)±SD 为 0.62±0.21，社区特定的平均值范围从北卡罗来纳州温斯顿-塞勒姆的 0.47±0.15 到纽约的 0.82±0.14。F(inf)在温暖（>18°C）季节通常更高。在温暖季节中，中央空调（AC）使用、AC 使用频率和开窗频率是最重要的预测因素；而在寒冷季节中，室外温度和强制空气加热则是最佳的预测因素。这些模型可以预测 2 周 F(inf)的 60%的方差，RMSE 为 0.13。
我们开发了直观的模型，可以使用容易获得的变量来预测 F(inf)。使用这些模型，MESA Air 将是第一个将住宅 F(inf)的变化纳入暴露评估的大型流行病学研究。
