Indoor air quality in junior high schools in Reykjavík

Apart from the home, the school environment is probably the most important indoor environment for children and adolescents. Children spend as much as 80-90% of their indoor time either at school or at home. In Iceland, school, and thereby its environment, is compulsory for children between 6-16 years of age. Several recent studies have concluded that the environment at school may affect the pupils’ respiratory health and learning ability. The this study was to study the indoor air quality in junior high schools in Reykjavik with particular emphasis on levels of PM10 and ultra-fine particles(UFP). Measurements were performed in 74 classrooms in 15 public junior high schools in the Reykjavik city area. All the classrooms were occupied during measurements by children in 8th and 9th grade (13-15 years old) and their teachers. Levels of CO2, PM10, UFP, temperature and RH% were measured in each classroom. An environmental inspection was also performed in each classroom,where the fleece factor (m2/m3), shelf factor (m/m3), number of persons per room volume (pers/m3), personal outdoor air supply rate (L/s/person) and the air exchange rate (ac/hour) were measured and calculated. Levels of PM10 and UFP were measured immediately outside the 15 studied schools. A Kendall’s tau-b correlation analysis was used to study potential correlations within and/or between indoor climatic and environmental factors. The same method was used to study correlations within and/or between levels of indoor PM10 and UFP, and outdoor levels of PM10 and UFP. Results were compared with those from comparable school studies in Taiyuan, China and Uppsala, Sweden. The results indicate a need for improvement in the indoor climate in junior high schools in Reykjavik. Mean levels of CO2 in the classrooms were 1510 ppm, and significantly above the recommended max limit value of 1000 ppm. In approximately 87% of the schools mean CO2 levels lay above the recommended max limit. The mean level of PM10 in the classrooms was 40.4 µg/m3, ranging between 6.3-162 µg/m3. The mean level of UFP in the classrooms was 8961 particles/cm3 and ranged between 890-92692 particles/cm3. The mean relative air humidity (RH%) in classrooms was 33%, with a range between 16.9-54.7%. The mean room temperature in the classrooms was 21.7 °C, ranging between 18.3-25.5°C. The mean temperature in each school ranged between 20.4-22.8°C. The mean number of persons per cubic meter in the classrooms was 0.104 pers/m3, and ranged between 0.02-0.17 pers/m3. The mean personal outdoor air supply rate in the classrooms was 4.7 L/s/person, and ranged between 1.5-39.7 L/s/person. Approximately 87% of the schools had a mean personal outdoor air supply rate below the recommended minimum rate (8 l/sperson). The mean air exchange rate in the classrooms was 1.6 ac/hour, and ranged between 0.5-17.2 ac/hour. All of the schools had an air exchange rate that exceeded the recommended minimum (0.8 ac/hour). The results showed no significant correlation between measured outdoor levels of PM10 and UFP and indoor levels of PM10 and UFP in the classrooms.Reykjavik Energy's Environmental and Resource Fun