Max Planck Institute for Chemistry, Hahn-Meitner Weg 1, 55128 Mainz, Germany.
International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Lyngby 2800, Denmark.
Environ Sci Technol. 2020 May 5;54(9):5419-5428. doi: 10.1021/acs.est.0c00094. Epub 2020 Apr 14.
Ammonia (NH) is typically present at higher concentrations in indoor air (∼10-70 ppb) than in outdoor air (∼50 ppt to 5 ppb). It is the dominant neutralizer of acidic species in indoor environments, strongly influencing the partitioning of gaseous acidic and basic species to aerosols, surface films, and bulk water. We have measured NH emissions from humans in an environmentally controlled chamber. A series of experiments, each with four volunteers, quantified NH emissions as a function of temperature (25.1-32.6 °C), clothing (long-sleeved shirts/pants or T-shirts/shorts), age (teenagers, adults, and seniors), relative humidity (low or high), and ozone (<2 ppb or ∼35 ppb). Higher temperature and more skin exposure (T-shirts/shorts) significantly increased emission rates. For adults and seniors (long clothing), NH emissions are estimated to be 0.4 mg h person at 25 °C, 0.8 mg h person at 27 °C, and 1.4 mg h person at 29 °C, based on the temperature relationship observed in this study. Human NH emissions are sufficient to neutralize the acidifying impacts of human CO emissions. Results from this study can be used to more accurately model indoor and inner-city outdoor NH concentrations and associated chemistry.
氨（NH）通常在室内空气中的浓度比在室外空气中高（约为 10-70 ppb）（约为 50 ppt 至 5 ppb）。它是室内环境中酸性物质的主要中和剂，强烈影响气态酸性和碱性物质向气溶胶、表面膜和体相水的分配。我们已经在环境控制室内测量了人类排放的氨。一系列实验，每个实验有四名志愿者，定量测量了氨的排放，其影响因素包括温度（25.1-32.6°C）、衣物（长袖衬衫/裤子或 T 恤/短裤）、年龄（青少年、成年人和老年人）、相对湿度（低或高）和臭氧（<2 ppb 或约 35 ppb）。更高的温度和更多的皮肤暴露（T 恤/短裤）会显著增加排放速率。对于成年人和老年人（穿着长袖衣物），根据本研究中观察到的温度关系，氨排放量估计为 25°C 时 0.4 mg h 人，27°C 时 0.8 mg h 人，29°C 时 1.4 mg h 人。人类的氨排放足以中和人类 CO 排放的酸化影响。本研究的结果可用于更准确地模拟室内和城市内部户外 NH 浓度及其相关化学物质。
