The transformation of outdoor ammonium nitrate aerosols in the indoor environment
The transformation of outdoor ammonium nitrate aerosols in the indoor environment
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DOI：
10.1016/j.atmosenv.2003.09.035
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发表时间：
2003-12-01
影响因子：
5
通讯作者：
Brown, NJ
中科院分区：
文献类型：
--
作者：
Lunden, MM;Revzan, KL;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；然而，暴露于室外来源的室内颗粒并没有很好地表征，特别是对于个别化学物质。我们在加利福尼亚州克洛维斯的一所无人居住的单层住宅中进行了实地研究，以提供数据和分析，以解决评估暴露的重要问题。我们在室外和室内使用实时颗粒监测器来量化粒径小于等于2.5微米的硝酸盐、硫酸盐和碳颗粒物质（PM-2.5）。结果表明，室内测量的硝酸铵浓度明显低于仅根据渗透和沉积损失预测的浓度。额外的减少可归因于硝酸铵在室内转化为氨和硝酸气体，这些气体随后通过沉积和吸附到室内表面而损失。考虑硝酸铵蒸发动力学的质量平衡模型能够重现测量的室内硝酸铵和硝酸浓度，从而得出硝酸沉积速度的拟合值为0.56 cm s（-1）。结果表明，加州中央谷地室内暴露于室外硝酸铵的量很小，并且表明基于室外测量的总颗粒质量的暴露评估可能会模糊室内暴露于室外颗粒的实际因果关系。(C) 2003 Elsevier Ltd.版权所有。
Recent studies associate particulate air pollution with adverse health effects; however, the exposure to indoor particles of outdoor origin is not well characterized, particularly for individual chemical species. We conducted a field study in an unoccupied, single-story residence in Clovis, California to provide data and analyses to address issues important for assessing exposure. We used real-time particle monitors both outdoors and indoors to quantify nitrate, sulfate, and carbon particulate matter of particle size 2.5 mum or less in diameter (PM-2.5). The results show that measured indoor ammonium nitrate concentrations were significantly lower than would be expected based solely on penetration and deposition losses. The additional reduction can be attributed to the transformation indoors of ammonium nitrate into ammonia and nitric acid gases, which are subsequently lost by deposition and sorption to indoor surfaces. A mass balance model that accounts for the kinetics of ammonium nitrate evaporation was able to reproduce measured indoor ammonium nitrate and nitric acid concentrations, resulting in a fitted value of the deposition velocity for nitric acid of 0.56 cm s(-1). The results indicate that indoor exposure to outdoor ammonium nitrate in Central Valley of California are small, and suggest that exposure assessments based on total particle mass measured outdoors may obscure the actual causal relationships for indoor exposure to particles of outdoor origin. (C) 2003 Elsevier Ltd. All rights reserved.