Nassri Mahdi, Barari Parviz, Khanizadeh Mohammad, Faridi Sasan, Shamsipour Mansour, Naddafi Kazem, Niazi Sadegh, Hassanvand Mohammad Sadegh
Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
Heliyon. 2024 Aug 22;10(16):e36626. doi: 10.1016/j.heliyon.2024.e36626. eCollection 2024 Aug 30.
This study aimed to assess the impact of wearing N95 and surgical masks on carbon dioxide (CO) concentrations during various activity levels, to understand the implications for mask use in different settings, especially in light of the COVID-19 pandemic.
Systematic Review and Meta-Analysis.
A systematic review was conducted, retrieving 6798 articles from PubMed, Web of Science, and Scopus databases. Twenty-nine articles met the inclusion criteria. Mask types were categorized into N95 and surgical masks, while activities were classified as low, medium, and high.
The meta-analysis revealed CO concentrations (mmHg) for different scenarios: No mask (37.91, 95 % CI: 36.46, 39.35), N95-low (36.83, 95 % CI: 33.57, 40.10), N95-moderate (37.85, 95 % CI: 36.51, 39.20), N95-high (39.51, 95 % CI: 38.00, 41.02), N95 with exhalation valve (35.82, 95 % CI: 32.89, 38.75), N95 without exhalation valve (38.45, 95 % CI: 37.10, 39.81), surgical mask-low (38.31, 95 % CI: 34.48, 42.14), surgical mask-moderate (35.05, 95 % CI: 31.12, 38.97), surgical mask-high (36.07, 95 % CI: 34.18, 37.96).
Our findings indicate that N95 masks lead to higher CO accumulation during various activities compared to surgical masks. Moreover, surgical masks exhibit higher CO concentrations during low activity compared to moderate and high activities. Notably, CO concentrations are higher in N95 masks without an exhalation valve compared to those with a valve. No significant difference was observed between not wearing a mask and wearing either N95 or surgical masks in terms of CO accumulation. These results provide important insights for mask selection and usage recommendations in different scenarios.
本研究旨在评估佩戴N95口罩和外科口罩对不同活动水平下二氧化碳（CO）浓度的影响，以了解在不同环境中使用口罩的意义，特别是鉴于2019冠状病毒病大流行。
系统评价和荟萃分析。
进行了一项系统评价，从PubMed、科学网和Scopus数据库中检索到6798篇文章。29篇文章符合纳入标准。口罩类型分为N95口罩和外科口罩，活动分为低、中、高三个等级。
荟萃分析揭示了不同场景下的CO浓度（mmHg）：不戴口罩（37.91，95%置信区间：36.46，39.35），N95口罩-低活动水平（36.83，95%置信区间：33.57，40.10），N95口罩-中等活动水平（37.85，95%置信区间：36.51，39.20），N95口罩-高活动水平（39.51，95%置信区间：38.00，41.02），带呼气阀的N95口罩（35.82，95%置信区间：32.89，38.75），不带呼气阀的N95口罩（38.45，95%置信区间：37.10，39.81），外科口罩-低活动水平（38.31，95%置信区间：34.48，42.14），外科口罩-中等活动水平（35.05，95%置信区间：31.12，38.97），外科口罩-高活动水平（36.07，95%置信区间：34.18，37.96）。
我们的研究结果表明，与外科口罩相比，N95口罩在各种活动中会导致更高的CO积聚。此外，与中等和高活动水平相比，外科口罩在低活动水平时CO浓度更高。值得注意的是，不带呼气阀的N95口罩的CO浓度高于带呼气阀的N95口罩。在CO积聚方面，不戴口罩与佩戴N95口罩或外科口罩之间未观察到显著差异。这些结果为不同场景下的口罩选择和使用建议提供了重要见解。
