北京空气质量差，那室内空气质量就好吗？ 谢郁宁，I'll call it Sirius 2. 分两个方面来答吧 第一、室外空气差的时候，室内空气受到多少影响？ 第二、影响室内空气质量的原因还有哪些？ 先答第一个吧 空气质量标准里面关注的大气组分有： 二氧化硫，二氧化氮，一氧化碳，臭氧，PM10，PM2.5，TSP，NOX，铅，苯并芘 不过现在引起热议的主要还是 PM2.5 吧。（过去关注的可是二氧化硫等哦，主要由于要控制酸雨等） 那么关于室外和室内的大气颗粒物的研究，已经有人做过观测对比了，1996 年还有个 review： Indoor particles: A review 老文了，找不到全文，但是看摘要也能看到一些 The impact of outdoor air particles on indoor concentrations was considered. Equilibrium mass balance models indicate that this is a function of the penetration P through the building envelope, the air exchange rate a, and the particle decay rate k. EPA's PTEAM Study provided an estimate for k of 0.39 h(-1) for fine particles and 1.01 h(-1) for coarse particles. Two studies suggest that P = 1 for PM(10). Using these results, the fraction of outdoor air PM(2.5) and PM(10) particles found indoors at a given air exchange rate can be calculated. The protective effect of reducing air exchange rates during periods of high outdoor particle pollution can thus be quantified. 室内受室外影响程度大小要看两个，一个是空气流通率，另一个是颗粒物清除率，室内的清除基本上能通过观测测量出来，还可以通过很多物理手段增强，PM2.5 慢一些，PM10 快一些（重力沉降快），那么控制空气流通率就能进一步加强建筑物对空气污染的阻隔率。 然后他们通过用入侵率（infiltration，室内浓度比室外浓度，表吐槽这个翻译）可以定义一下到底有多少室外的颗粒物污染能进到室内 那么，阻隔效率能有多少啊亲？ 看这篇，EST 的： Use of personal-indoor-outdoor sulfur concentrations to estimate the infiltration factor and outdoor exposure factor for individual homes and persons 还是看 abstract 就可以 One goal of the study was to estimate the contribution of outdoor PM2.5 to indoor concentrations. This depends on the infiltration factor F-inf, the fraction of outdoor PM2.5 remaining airborne after penetrating indoors. After confirming with our measurements the findings of previous studies that sulfur has few indoor sources, we estimated an average F-inf for each house based on indoor/outdoor sulfur ratios. These estimates ranged from 0.26 to 0.87, with a median value of 0.55. Since these estimates apply only to particles of size similar to that of sulfur particles (0.06-0.5 mu m diameter), and since larger particles (0.5-2.5 mu m) have lower penetration rates and higher deposition rates, these estimates are likely to be higher than the true infiltration factors for PM2.5 as a whole. In summer when air conditioners were in use, the sulfur-based infiltration factor was at its lowest (averaging 0.50) for most homes, whereas the average F-inf for the other three seasons was 0.62-0.63, Using the daily estimated infiltration factor for each house,we calculated the contribution of outdoor PM2.5 to indoor air concentrations. 对大部分参与实验的家庭来说，这个平均的入侵率在 0.55 左右，夏天开空调的时候入侵率最小（窗子都关了嘛），这个主要是由颗粒物中的硫酸根浓度来估算的，也就是说实际值应该会更低。 我花几百万在北京买的房子才能挡一半啊，渣渣！ 那么也许这幅图更加能让你明白高污染的时候呆在室内的意义： （source：Using Time- and Size-Resolved Particulate Data To Quantify Indoor Penetration and Deposition Behavior） 这是两个家庭的室内外同时观测的 PM2.5 浓度的时间序列图，上面那个图是某一家具有良好开窗习惯的家庭在某年夏天的观测结果，下面是某个具有良好关窗习惯家庭冬天的观测结果，室内和室外比还是差很多的，同时室内的高峰出现会比室外要晚那么一些，就是渗透过去还需要一点时间。 查看知乎原文
