Department of Chemistry, Syracuse University, Syracuse, New York 13244, USA.
Environ Sci Process Impacts. 2019 Aug 14;21(8):1374-1383. doi: 10.1039/c9em00129h.
Understanding the oxidizing environment indoors is important for predicting indoor air quality and its impact on human health. We made continuous time-resolved measurements (30 s) of several oxidants and oxidant precursors (collectively referred to as oxidant*): ozone (O3), nitric oxide (NO), and NO2* - the sum of nitrogen dioxide (NO2) and nitrous acid (HONO). These species were measured in three indoor environments - an occupied residence, a chemistry laboratory, and an academic office - in Syracuse, New York, during two seasons in 2017 and 2018. Oxidant* levels differed greatly between the residence, the lab and the office. Indoor-to-outdoor ratios (I/O) of O3 were 0.03 and 0.67 in the residence and office; I/ONO (I/ONO2*) were 11.70 (1.26) in the residence and 0.13 (1.70) in the office. Little seasonal variability was observed in the lab and office, but O3 and NO2* levels in the residence were greater in spring than in winter, while NO levels were lower. Human activities such as cooking and opening patio doors resulted in large changes in oxidant* mixing ratios in the residence. In situ chamber experiments demonstrated that the increase in O3 and NO2* levels during door-open periods was due to a combination of physical mixing between indoor and outdoor air, gas-phase production of NO2 from O3-NO chemistry, and heterogeneous formation of HONO on indoor surfaces. Our results also highlight the importance of chemistry (with NO, alkenes, and surfaces) in O3 mixing ratios in the residence, especially during door-open periods.
了解室内的氧化环境对于预测室内空气质量及其对人体健康的影响很重要。我们在 2017 年和 2018 年的两个季节，在纽约锡拉丘兹的三个室内环境（一个有人居住的住宅、一个化学实验室和一个学术办公室）中进行了连续的时间分辨测量（30 秒），测量了几种氧化剂和氧化剂前体（统称为氧化剂*）：臭氧（O3）、一氧化氮（NO）和 NO2*-二氧化氮（NO2）和亚硝（HONO）的总和。在住宅、实验室和办公室中，氧化剂的水平差异很大。O3 的室内与室外比值（I/O）在住宅和办公室中分别为 0.03 和 0.67；I/ONO（I/ONO2）在住宅中为 11.70（1.26），在办公室中为 0.13（1.70）。在实验室和办公室中几乎没有观察到季节性变化，但住宅中的 O3 和 NO2水平在春季比冬季高，而 NO 水平较低。烹饪和打开露台门等人类活动导致住宅中氧化剂混合比发生了很大变化。现场室实验表明，开门期间 O3 和 NO2*水平的增加是由于室内和室外空气的物理混合、O3-NO 化学气相产生 NO2 以及室内表面上形成 HONO 的多相反应的综合作用。我们的研究结果还强调了化学物质（包括 NO、烯烃和表面）在住宅中 O3 混合比中的重要性，尤其是在开门期间。
