Department of Environmental Engineering, Chonnam National University, Gwangju, South Korea.
J Air Waste Manag Assoc. 2010 Dec;60(12):1434-42. doi: 10.3155/1047-3289.60.12.1434.
Nitrous acid (HONO) may cause adverse effects to mucous membranes and lung function when people are exposed to higher HONO concentrations than those present in typical indoor residential environments. Therefore, determination of HONO concentration in indoor environments is required to investigate occurrences of high HONO levels. In this work, a high-time-resolution measurement system was utilized to better understand the levels and dynamic behavior of HONO in an indoor environment. The performance of the in situ HONO analyzer applied to this work was evaluated using a 12-hr integrated annular denuder technique under ambient conditions. Both methods for the measurements of HONO were in good agreement, with a regression slope of 0.84, an intercept of 0.09, and correlation coefficient (r2) of 0.67. Indoor HONO and nitrogen oxide concentrations were also observed for approximately 5 days in winter in the living room of an apartment that had a gas range for cooking in the kitchen. Investigation of the relationships among nitric oxide (NO), nitrite (NO2), and HONO concentrations suggests that HONO production during combustion could be the result of direct emission, whereas the heterogeneous NO2 chemistry during the background period and after combustion was the possible pathway of HONO production. Controlled combustion experiments, performed at a burning rate of 50% valve setting, show peak HONO concentrations during the unvented combustion to be approximately 8-10 times higher than background levels depending on the time of day. At a burning rate setting of 50%, the peak concentration of HONO during unvented combustion was found to be 33-37% higher than those from "weak" (airflow = 340 m3/hr) and "strong" (airflow = 540 m3/hr) vented combustions. The decay rate of the HONO concentrations for the unvented combustion conditions was approximately 2-fold higher in the daytime than in the nighttime and significantly less than those of NO and NO2.
当人们暴露在高于典型室内居住环境中存在的 HONO 浓度时，亚硝酸（HONO）可能会对粘膜和肺功能造成不良影响。因此，需要测定室内环境中的 HONO 浓度，以调查高 HONO 水平的发生情况。在这项工作中，使用高时间分辨率测量系统来更好地了解室内环境中 HONO 的水平和动态行为。在环境条件下，应用 12 小时积分环形吹脱技术评估了原位 HONO 分析仪的性能。两种 HONO 测量方法的结果非常吻合，回归斜率为 0.84，截距为 0.09，相关系数（r2）为 0.67。在冬季，大约在公寓的客厅中进行了为期 5 天的室内 HONO 和氮氧化物浓度的测量，该公寓的厨房中有用于烹饪的燃气炉灶。对一氧化氮（NO）、亚硝酸盐（NO2）和 HONO 浓度之间的关系进行了研究，结果表明，燃烧过程中的 HONO 生成可能是直接排放的结果，而背景时期和燃烧后的异相 NO2 化学则是 HONO 生成的可能途径。在燃烧速率为 50%的阀门设置下进行的受控燃烧实验表明，在无通风燃烧期间，峰值 HONO 浓度取决于一天中的时间，约为背景水平的 8-10 倍。在燃烧速率为 50%的情况下，无通风燃烧期间的 HONO 峰值浓度比“弱”（气流=340 m3/h）和“强”（气流=540 m3/h）通风燃烧的浓度高 33-37%。无通风燃烧条件下 HONO 浓度的衰减率在白天约为夜间的 2 倍，明显低于 NO 和 NO2 的衰减率。
