Twardella D, Fromme H, Dietrich S, Dietrich W C
Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, Sachgebiet Umweltmedizin, Veterinärstrasse 2, Oberschleissheim.
Gesundheitswesen. 2009 Feb;71(2):70-6. doi: 10.1055/s-0028-1086007. Epub 2009 Feb 23.
The aims of the research project were (I) to describe the exposure to particulate matter in Bavarian schools and identify predictors of increased exposure and (II) to evaluate whether exposure can be reduced by improving the ventilation and/or cleaning routine. Air quality was measured in 46 schools, two classrooms each, in the City of Munich and Dachau county. Each classroom was measured on one school day in both winter 2004/2005 and summer 2005. The continuously generated data on particulate matter during the teaching hours were summarised to daily medians and the possible association of the median concentration with classroom characteristics was tested using non-parametric methods. In winter, the median PM (2.5) concentration was 18.8 microg/m (3), in summer 12.7 microg/m (3). The median PM (10) concentration was 91.5 microg/m (3) in winter and 64.9 microg/m (3) in summer. Determinants of a high particulate matter concentration were the winter period, an increased number of pupils or decreased room size, a high CO(2) concentration, and a low class level. Following this survey, a pilot study on the effects of improved cleaning and ventilation routines was conducted in autumn 2005. Three conditions were tested in two classrooms of one school: (a) standard, (b) improved airing (3 min during short and 20 min during long breaks), and (c) improved airing and improved cleaning (thorough cleaning once and vacuuming before wet wiping). Each condition was implemented for 2 weeks and particulate matter concentrations measured concurrently. In both rooms a reduction of both PM (2.5) and PM (10) concentration was found following improved airing and a further reduction occurred when improved cleaning was introduced in addition. However, in a linear regression accounting for other factors (room, physical activity of the pupils, outdoor concentration of particulate matter) the effect of improved airing was no longer significant, while the effect of improved cleaning remained at a reduction of 6 microg/m (3) for PM (2.5) and of 30 microg/m (3) for PM (10). The research projects show, that exposure to particulate matter in schools is high and indicate that, in particular, improved cleaning may be an effective measure to reduce the indoor particulate matter concentration. More and larger studies are needed to prove the efficacy of this measure.
（I）描述巴伐利亚州学校中颗粒物的暴露情况，并确定暴露增加的预测因素；（II）评估是否可以通过改善通风和/或清洁程序来降低暴露水平。在慕尼黑市和达豪县的46所学校中，每所学校选取两个教室测量空气质量。在2004/2005年冬季和2005年夏季的一个教学日对每个教室进行测量。将教学时间内持续生成的颗粒物数据汇总为每日中位数，并使用非参数方法测试中位数浓度与教室特征之间的可能关联。冬季，PM（2.5）浓度中位数为18.8微克/立方米，夏季为12.7微克/立方米。冬季PM（10）浓度中位数为91.5微克/立方米，夏季为64.9微克/立方米。颗粒物浓度高的决定因素包括冬季、学生人数增加或教室面积减小、二氧化碳浓度高以及班级楼层低。此次调查之后，于2005年秋季开展了一项关于改善清洁和通风程序效果的试点研究。在一所学校的两个教室中测试了三种情况：（a）标准情况；（b）改善通风（课间短休息时通风3分钟，长休息时通风20分钟）；（c）改善通风并改善清洁（彻底清洁一次，湿擦前吸尘）。每种情况实施2周，并同时测量颗粒物浓度。在两个房间中，改善通风后PM（2.5）和PM（10）浓度均有所降低，此外引入改善清洁措施后浓度进一步降低。然而，在考虑其他因素（房间、学生的身体活动、室外颗粒物浓度）的线性回归分析中，改善通风的效果不再显著，而改善清洁的效果仍使PM（2.5）降低6微克/立方米，PM（10）降低30微克/立方米。这些研究项目表明，学校中颗粒物暴露水平较高，并表明特别是改善清洁可能是降低室内颗粒物浓度的有效措施。需要更多且规模更大的研究来证明该措施的有效性。
