Dedesko Sandra, Pendleton Joseph, Young Anna S, Coull Brent A, Spengler John D, Allen Joseph G
Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Harvard Graduate School of Arts and Sciences, Cambridge, MA, USA.
J Expo Sci Environ Epidemiol. 2025 Apr 9. doi: 10.1038/s41370-025-00770-6.
Past work demonstrating an association between indoor air quality and cognitive performance brought attention to the benefits of increasing outdoor air ventilation rates beyond code minimums. These code minimums were scrutinized during the COVID-19 pandemic for insufficient ventilation and filtration specifications. As higher outdoor air ventilation was recommended in response, questions arose about potential benefits of enhanced ventilation beyond infection risk reduction.
This was investigated by examining associations between indoor carbon dioxide concentrations, reflective of ventilation and building occupancy, and cognitive test scores among graduate students attending lectures in university classrooms with infection risk management strategies, namely increased ventilation.
Post-class cognitive performance tests (Stroop, assessing inhibitory control and selective attention; Arithmetic, assessing cognitive speed and working memory) were administered through a smartphone application to participating students (54 included in analysis) over the 2022-2023 academic year in classrooms equipped with continuous indoor environmental quality monitors that provided real-time measurements of classroom carbon dioxide concentrations. Temporally and spatially paired exposure and outcome data was used to construct mixed effects statistical models that examined different carbon dioxide exposure metrics and cognitive test scores.
Model estimates show directionally consistent evidence that higher central and peak classroom carbon dioxide concentrations, indicative of ventilation and occupancy, are associated with lower cognitive test scores over the measured range included in analysis ( ~ 440-1630 ppm). The effect estimates are strongest for 95th percentile class carbon dioxide concentrations, representing peak class carbon dioxide exposures.
As the COVID-19 pandemic eased, questions emerged on the benefits of increased outdoor air ventilation beyond infection reduction. This work assesses associations between carbon dioxide concentrations, indicative of ventilation and occupancy, and cognitive test scores among students in university classrooms with increased outdoor air ventilation. Although not causal, models show statistically significant evidence of associations between lower carbon dioxide concentrations and higher cognitive test scores over the low range of carbon dioxide exposures in these classrooms. While the underlying mechanisms remain unknown, higher outdoor air ventilation appears to provide additional benefits by reducing indoor air exposure and supporting student performance.
过去的研究表明室内空气质量与认知表现之间存在关联，这使得人们开始关注将室外空气通风率提高到建筑规范最低要求之上的益处。在新冠疫情期间，这些规范最低要求因通风和过滤规格不足而受到审视。由于建议提高室外空气通风量，人们开始质疑增强通风除了降低感染风险之外是否还有其他潜在益处。
通过研究室内二氧化碳浓度（反映通风情况和建筑内人员密度）与在采取了感染风险管理策略（即增加通风）的大学教室里上课的研究生的认知测试分数之间的关联，对此进行调查。
在2022 - 2023学年，通过智能手机应用程序对参与研究的学生（分析中纳入54名）进行课后认知表现测试（斯特鲁普测试，评估抑制控制和选择性注意力；算术测试，评估认知速度和工作记忆）。这些教室配备了室内环境质量连续监测仪，可实时测量教室二氧化碳浓度。使用时间和空间上配对的暴露和结果数据构建混合效应统计模型，以研究不同的二氧化碳暴露指标与认知测试分数之间的关系。
模型估计显示出方向一致的证据，即在分析所涵盖的测量范围内（约440 - 1630 ppm），较高的教室中心和峰值二氧化碳浓度（表明通风情况和人员密度）与较低的认知测试分数相关。对于第95百分位数的班级二氧化碳浓度（代表班级二氧化碳峰值暴露），效应估计最为显著。
随着新冠疫情缓解，人们对增加室外空气通风量除了减少感染之外的益处提出了疑问。这项研究评估了在增加室外空气通风的大学教室里，反映通风情况和人员密度的二氧化碳浓度与学生认知测试分数之间的关联。虽然并非因果关系，但模型显示在这些教室中低二氧化碳暴露范围内，较低的二氧化碳浓度与较高的认知测试分数之间存在具有统计学意义的关联证据。虽然潜在机制尚不清楚，但增加室外空气通风似乎通过减少室内空气暴露和支持学生表现带来了额外益处。
