Use of time- and chemically resolved particulate data to characterize the infiltration of outdoor PM2.5 into a residence in the San Joaquin Valley
Use of time- and chemically resolved particulate data to characterize the infiltration of outdoor PM2.5 into a residence in the San Joaquin Valley
复制标题
DOI：
10.1021/es026387i
复制
发表时间：
2003-10-15
影响因子：
11.4
通讯作者：
Brown, NJ
中科院分区：
文献类型：
--
作者：
Lunden, MM;Thatcher, TL;Brown, NJ
最近的研究将颗粒空气污染与不利的健康影响联系起来。室内暴露于室外来源的颗粒物的特征尚不明确，特别是对于单个化学物质。针对这一点，在加利福尼亚州克洛维斯的一个无人居住的单层住宅中进行了实地研究。在室内和室外都使用了实时颗粒物监测器来定量PM2.5硝酸盐，硫酸盐和碳。聚合的高度时间分辨的硫酸盐数据，以及平均值，这些数据，适合使用时间平均形式的渗透方程，从而在合理的值的渗透系数和沉积损失率。相比之下，室内/室外比率的个体值可能与模型针对从几分钟到几小时的时间尺度所预测的值显著不同。测量的室内硝酸铵水平通常明显低于仅根据渗透和沉积损失的预期。进一步减少是由于硝酸铵在室内转化为氨和硝酸气体，随后通过沉积和吸附到室内表面而损失。这一结果表明，基于室外颗粒物总质量的暴露评估可能会掩盖室内暴露与室外来源颗粒物的实际因果关系。
Recent studies associate particulate air pollution with adverse health effects. The indoor exposure to particles of outdoor origin is not well-characterized, particularly for individual chemical species. In response to this, a field study in an unoccupied, single-story residence in Clovis, CA, was conducted. Real-time particle monitors were used both outdoors and indoors to quantity PM2.5 nitrate, sulfate, and carbon. The aggregate of the highly time-resolved sulfate data, as well as averages, of these data, was fit using a time-averaged form of the infiltration equation, resulting in reasonable values for the penetration coefficient and deposition loss rate. In contrast, individual values of the indoor/outdoor ratio can vary significantly from that predicted by the model for time scales ranging from a few minutes to several hours. Measured indoor ammonium nitrate levels were typically significantly lower than expected solely on the basis of penetration and deposition losses. The additional reduction is due to the transformation of ammonium nitrate into ammonia and nitric acid gases indoors, which are subsequently lost by deposition and sorption to indoor surfaces. This result illustrates that exposure assessments based on total outdoor particle mass can obscure the actual causal relationships for indoor exposures to particles of outdoor origin.