Faculty of Physics, Departments of Environmental Physics and Meteorology, University of Athens, University Campus, Athens, 157 84, Greece.
Faculty of Physics, Departments of Environmental Physics and Meteorology, University of Athens, University Campus, Athens, 157 84, Greece.
Sci Total Environ. 2015 Jan 1;502:557-70. doi: 10.1016/j.scitotenv.2014.09.060. Epub 2014 Oct 7.
Ventilation rates and indoor air pollutants have been extensively monitored in nine naturally ventilated primary schools of Athens, Greece during spring. The ventilation rates and pollutant levels were studied during the teaching and non-teaching periods and ventilation profiles were created for each of the schools. The median ventilation rates per school ranged between 0.7 and 8 ACH while the average ventilation rate in all schools (11.7l/s/p) was greater than the minimum recommended rates by ASHRAE for school classrooms. The average carbon dioxide (CO2) concentrations per school varied between 893 and 2082ppm, while the majority of the cases were slightly above the recommended limit values. CO2 concentrations were also positively correlated to the number of students and negatively correlated to the ventilation rates. Particles of several size ranges (PM10, PM5, PM2.5, PM1, PM0.5 and UFP) were also measured and analyzed. PM10 concentrations exceeded the recommended limit values by more than 10 times for the majority of the cases. There were also many cases that the PM2.5 concentrations exceeded their limit values. PM concentrations were significantly affected by the ventilation rates and the presence of students. All of the measured particle sizes were greater during teaching than the non-teaching hours. For most of the cases the indoor to outdoor (I/O) concentrations ratios of PM10 and PM2.5 were much greater than one, indicating that the indoor environment was being mostly affected by indoor sources instead of the outdoor air. Furthermore it was found that chalk and marker boards' usage significantly affect indoor pollutant concentrations. Overall, the measured levels of exposure were for most of the cases greater than the recommended guideline values due to the intense presence of indoor pollution sources, even though the ventilation rates were in general satisfactory.
在希腊雅典的九所自然通风的小学，我们在春季期间广泛监测了通风率和室内空气污染物。我们研究了教学和非教学时段的通风率和污染物水平，并为每所学校创建了通风特征图。每所学校的中位数通风率在 0.7 到 8 ACH 之间，而所有学校的平均通风率（11.7l/s/p）大于 ASHRAE 为学校教室推荐的最低值。每所学校的平均二氧化碳（CO2）浓度在 893 到 2082ppm 之间变化，而大多数情况略高于推荐的限值。CO2 浓度与学生人数呈正相关，与通风率呈负相关。还测量和分析了几个大小范围的颗粒（PM10、PM5、PM2.5、PM1、PM0.5 和 UFP）。在大多数情况下，PM10 浓度超过推荐限值 10 倍以上。还有许多 PM2.5 浓度超过其限值的情况。PM 浓度受通风率和学生人数的显著影响。在教学期间，所有测量的粒径都大于非教学时间。在大多数情况下，室内到室外（I/O）的 PM10 和 PM2.5 浓度比大于 1，表明室内环境主要受到室内源的影响，而不是室外空气。此外，还发现粉笔和标记板的使用会显著影响室内污染物浓度。总体而言，由于室内污染源的强烈存在，即使通风率通常令人满意，大多数情况下测量的暴露水平仍高于推荐的指导值。
