Institute of Nuclear and Radiological Science & Technology, National Centre for Scientific Research "Demokritos," Athens, Greece.
J Air Waste Manag Assoc. 2013 Oct;63(10):1113-29. doi: 10.1080/10962247.2013.791649.
Recent toxicological results highlight the importance of separating exposure to indoor- and outdoor-generated particles, due to their different physicochemical and toxicological properties. In this framework, a number of studies have attempted to estimate the relative contribution of particles of indoor and outdoor origins to indoor concentrations, using either statistical analysis of indoor and outdoor concentration time-series or mass balance equations. The aim of this work is to review and compare the methodologies developed in order to determine the ambient particle infiltration factor (F(INF)) (i.e., the fraction of ambient particles that enter indoors and remains suspended). The different approaches are grouped into four categories according to their methodological principles: (1) steady-state assumption using the steady-state form of the mass balance equation; (2) dynamic solution of the mass balance equation using complex statistical techniques; (3) experimental studies using conditions that simplify model calculations (e.g., decreasing the number of unknowns); and (4) infiltration surrogates using a particulate matter (PM) constituent with no indoor sources to act as surrogate of indoor PM of outdoor origin. Examination of the various methodologies and results reveals that estimating infiltration parameters is still challenging. The main difficulty lies in the separate calculation of penetration efficiency (P) and deposition rate (k). The values for these two parameters that are reported in the literature vary significantly. Deposition rate presents the widest range of values, both between studies and size fractions. Penetration efficiency seems to be more accurately calculated through the application of dynamic models. Overall, estimates of the infiltration factor generated using dynamic models and infiltration surrogates show good agreement. This is a strong argument in favor of the latter methodology, which is simple and easy to apply when chemical speciation data are available.
最近的毒理学研究结果强调了将室内和室外生成的颗粒物暴露区分开来的重要性，因为它们具有不同的物理化学和毒理学特性。在这一框架内，许多研究试图使用室内和室外浓度时间序列的统计分析或质量平衡方程来估计室内浓度中室内和室外来源颗粒的相对贡献。本工作旨在回顾和比较为确定环境颗粒渗透因子（F(INF)）（即进入室内并保持悬浮状态的环境颗粒分数）而开发的方法。根据其方法原理，将不同方法分为四类：(1) 使用质量平衡方程的稳态形式的稳态假设；(2) 使用复杂统计技术的质量平衡方程的动态解；(3) 使用简化模型计算的实验研究（例如，减少未知数的数量）；以及 (4) 使用无室内源的颗粒物 (PM) 成分作为室外源室内 PM 的替代物的渗透替代物。对各种方法和结果的检查表明，估算渗透参数仍然具有挑战性。主要困难在于单独计算穿透效率 (P) 和沉积速率 (k)。文献中报告的这两个参数的值差异很大。沉积速率在不同研究和粒径之间的变化范围最大。通过应用动态模型似乎可以更准确地计算穿透效率。总体而言，使用动态模型和渗透替代物生成的渗透因子估计值具有很好的一致性。这有力地支持了后一种方法，该方法简单易用，并且在有化学形态数据时更容易应用。
