Department of Mechanical and Materials Engineering, Portland State University, Portland, Oregon 97201, United States.
Berkeley Education Alliance for Research in Singapore, Singapore 138602.
Environ Sci Technol. 2021 Jan 5;55(1):139-148. doi: 10.1021/acs.est.0c03850. Epub 2020 Dec 10.
The human body emits a wide range of chemicals, including CO and isoprene. To examine the impact of cognitive tasks on human emission rates of CO and isoprene, we conducted an across-subject, counterbalanced study in a controlled chamber involving 16 adults. The chamber replicated an office environment. In groups of four, participants engaged in 30 min each of cognitive tasks (stressed activity) and watching nature documentaries (relaxed activity). Measured biomarkers indicated higher stress levels were achieved during the stressed activity. Per-person CO emission rates were greater for stressed than relaxed activity (30.3 ± 2.1 vs 27.0 ± 1.7 g/h/p, = 0.0044, mean ± standard deviation). Isoprene emission rates were also elevated under stressed versus relaxed activity (154 ± 25 μg/h/p vs 116 ± 20 μg/h/p, = 0.041). The chamber temperature was held constant at 26.2 ± 0.49 °C; incidental variation in temperature did not explain the variance in emission rates. Isoprene emission rates increased linearly with salivary α-amylase levels ( = 0.6, = 0.02). These results imply the possibility of considering cognitive tasks when determining building ventilation rates. They also present the possibility of monitoring indicators of cognitive tasks of occupants through measurement of air quality.
人体排放出多种化学物质，包括 CO 和异戊二烯。为了研究认知任务对人体 CO 和异戊二烯排放率的影响，我们在一个控制室内进行了一项跨主题、平衡的研究，涉及 16 名成年人。该室复制了一个办公室环境。参与者四人一组，分别进行 30 分钟的认知任务（紧张活动）和观看自然纪录片（放松活动）。测量的生物标志物表明，在紧张活动期间达到了更高的压力水平。与放松活动相比，个体的 CO 排放率在紧张活动时更高（30.3 ± 2.1 对 27.0 ± 1.7 g/h/p， = 0.0044，平均值 ± 标准差）。异戊二烯排放率在紧张活动时也高于放松活动时（154 ± 25 μg/h/p 对 116 ± 20 μg/h/p， = 0.041）。室内温度保持在 26.2 ± 0.49°C；温度的偶然变化不能解释排放率的变化。异戊二烯排放率与唾液 α-淀粉酶水平呈线性关系（ = 0.6， = 0.02）。这些结果表明，在确定建筑物通风率时，可能需要考虑认知任务。它们还提出了通过测量空气质量来监测居住者认知任务指标的可能性。
