Sarnat Stefanie Ebelt, Coull Brent A, Schwartz Joel, Gold Diane R, Suh Helen H
Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, USA.
Environ Health Perspect. 2006 May;114(5):649-54. doi: 10.1289/ehp.8422.
Results from air pollution exposure assessment studies suggest that ambient fine particles [particulate matter with aerodynamic diameter<or=2.5 microg (PM2.5)], but not ambient gases, are strong proxies of corresponding personal exposures. For particles, the strength of the personal-ambient association can differ by particle component and level of home ventilation. For gases, however, such as ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), the impact of home ventilation on personal-ambient associations is untested. We measured 24-hr personal exposures and corresponding ambient concentrations to PM2.5, sulfate (SO2-(4)), elemental carbon, O3, NO2, and SO2 for 10 nonsmoking older adults in Steubenville, Ohio. We found strong associations between ambient particle concentrations and corresponding personal exposures. In contrast, although significant, most associations between ambient gases and their corresponding exposures had low slopes and R2 values; the personal-ambient NO2 association in the fall season was moderate. For both particles and gases, personal-ambient associations were highest for individuals spending most of their time in high- compared with low-ventilated environments. Cross-pollutant models indicated that ambient particle concentrations were much better surrogates for exposure to particles than to gases. With the exception of ambient NO2 in the fall, which showed moderate associations with personal exposures, ambient gases were poor proxies for both gas and particle exposures. In combination, our results suggest that a) ventilation may be an important modifier of the magnitude of effect in time-series health studies, and b) results from time-series health studies based on 24-hr ambient concentrations are more readily interpretable for particles than for gases.
空气污染暴露评估研究结果表明，环境细颗粒物[空气动力学直径≤2.5微米的颗粒物（PM2.5）]，而非环境气体，是相应个人暴露的有力替代指标。对于颗粒物而言，个人与环境之间关联的强度会因颗粒成分和家庭通风水平而有所不同。然而，对于气体，如臭氧（O3）、二氧化氮（NO2）和二氧化硫（SO2），家庭通风对个人与环境关联的影响尚未得到验证。我们测量了俄亥俄州斯特本维尔市10名不吸烟老年人24小时的个人暴露量以及相应的环境浓度，涉及PM2.5、硫酸盐（SO2-(4)）、元素碳、O3、NO2和SO2。我们发现环境颗粒物浓度与相应的个人暴露之间存在很强的关联。相比之下，尽管环境气体与相应暴露之间的大多数关联具有显著性，但斜率和R2值较低；秋季个人与环境的NO2关联程度中等。对于颗粒物和气体，在通风良好环境中度过大部分时间的个体，其个人与环境的关联最高。交叉污染物模型表明，环境颗粒物浓度作为颗粒物暴露的替代指标比气体暴露要好得多。除了秋季环境NO2与个人暴露之间存在中等程度的关联外，环境气体作为气体和颗粒物暴露的替代指标都很差。综合来看，我们的结果表明：a）通风可能是时间序列健康研究中效应大小的重要调节因素；b）基于24小时环境浓度的时间序列健康研究结果对于颗粒物比气体更容易解释。
