Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, United States.
Michigan State University, East Lansing, MI, United States.
Front Public Health. 2024 Oct 3;12:1427116. doi: 10.3389/fpubh.2024.1427116. eCollection 2024.
Many school buildings have inadequate ventilation, rudimentary if any air filtration, and aging and poorly maintained mechanical systems, all of which can lead to poor indoor air quality (IAQ). These issues are especially acute in environmental justice (EJ) communities where schools are located in polluted areas. This community-based participatory research examines how IAQ in naturally ventilated school buildings is affected by the use of air purifiers, air change rates, outdoor pollution levels, and teacher and staff behavior.
IAQ assessments were performed at two schools in Detroit, Michigan, which included building walk-through inspections and continuous indoor and outdoor measurements of black carbon (BC), particulate matter (PM and PM), carbon dioxide (CO), air change rates (ACRs), temperature, humidity, and sound pressure levels. Air purifiers with usage monitors were then installed, and the IAQ assessments were repeated. Teachers were surveyed before and after purifier deployment.
At baseline, classrooms had low ACRs (0.58-1.38 h), moderate PM levels (2.8-8.9 μg/m), highly variable PM concentrations (4.7-37.5 μg/m), and elevated BC levels (0.3-0.7 μg/m), reflecting emissions from local traffic, industry and other sources. The installation and use of purifiers reduced pollutant levels and the overall performance matched the predictions of a single compartment model. However, daily reductions varied widely among classrooms, reflecting differences in teacher behavior regarding the frequency of opening windows and the operation of purifiers, including differences in purifier fan speed settings and whether purifiers were used at night. Survey responses indicated that many teachers were aware of IAQ problems. The higher rates reported for health symptoms and dissatisfaction at one school may have lowered the teachers' tolerance to noise and reduced purifier use.
The study helps explain the variation reported in prior studies using purifiers, and it reinforces the need to monitor IAQ and purifier use, use enhanced filtration and increase ventilation, and engage with teachers and school staff to support and maintain IAQ programs in schools.
许多学校建筑通风不足，空气过滤基本没有，如果有的话，也是很简陋的，而且其机械系统老化且维护不善，所有这些都可能导致室内空气质量 (IAQ) 较差。这些问题在环境正义 (EJ) 社区中尤为突出，这些社区中的学校位于污染地区。本项基于社区的参与性研究考察了在自然通风的学校建筑中，空气净化器的使用、空气交换率、室外污染水平以及教师和工作人员的行为如何影响室内空气质量。
在密歇根州底特律的两所学校进行了室内空气质量评估，包括对建筑物进行巡视检查以及对室内外的黑碳 (BC)、颗粒物 (PM 和 PM)、二氧化碳 (CO)、空气交换率 (ACR)、温度、湿度和声压级进行连续测量。然后安装了带有使用监测器的空气净化器，并重复进行室内空气质量评估。在安装空气净化器前后对教师进行了调查。
在基线时，教室的空气交换率较低（0.58-1.38 h），颗粒物水平中等（2.8-8.9μg/m），颗粒物浓度变化较大（4.7-37.5μg/m），BC 水平较高（0.3-0.7μg/m），这反映了来自当地交通、工业和其他来源的排放。净化器的安装和使用降低了污染物水平，整体性能与单个隔室模型的预测相符。然而，教室之间的每日减少量差异很大，这反映了教师在开窗频率和净化器运行方面的行为差异，包括净化器风扇速度设置的差异以及净化器是否在夜间使用。调查结果表明，许多教师都意识到了室内空气质量问题。一所学校报告的健康症状和不满发生率较高，可能降低了教师对噪音的容忍度，并减少了净化器的使用。
该研究有助于解释之前使用净化器的研究报告中的差异，并强调需要监测室内空气质量和净化器使用情况，使用增强型过滤并增加通风，并与教师和学校工作人员合作，以支持和维护学校的室内空气质量计划。
