Respiratory symptoms, perceived air quality and physiological signs in elementary school pupils in relation to displacement and mixing ventilation system: an intervention study
2011 (English)In: Indoor Air, ISSN 0905-6947, E-ISSN 1600-0668, Vol. 21, no 5, 427-437 p.Article in journal (Refereed) Published
Schools may be poorly ventilated and may contain furry pet allergens, particles and microorganisms. We studied health effects when changing from mixing ceiling ventilation to two types of displacement ventilation, front ventilation system (FVS) and floor master system (FMS). The study included pupils in three elementary school classes (N = 61), all with floor heating. One class received blinded interventions; the two others were unchanged (controls). Ventilation flow and supply air temperature was kept constant. The medical investigation included tear film stability (BUT), nasal patency and a questionnaire containing rating scales. When changing from mixing ventilation to FVS, the pupils (N = 26) perceived better air quality (P = 0.006) and less dyspnoea (P = 0.007) as compared to controls (N = 35), and BUT was improved (P = 0.03). At desk level, mean CO(2) was reduced from 867 to 655 ppm. Formaldehyde and viable bacteria were numerically lower, while total bacteria and molds were higher with displacement ventilation. There was no difference in symptoms or signs when changing from FVS to FMS. Cat (Der p1), dog (Can f1) and horse allergen (Equ cx) were common in air at all conditions. In conclusion, displacement ventilation may have certain positive health effects among pupils, as compared to conventional mixing ceiling systems.
Place, publisher, year, edition, pages
2011. Vol. 21, no 5, 427-437 p.
Displacement ventilation, Biomarkers, School environment, Pupils, Tear film stability (BUT)
Medical and Health Sciences Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-159782DOI: 10.1111/j.1600-0668.2011.00717.xISI: 000295016400009OAI: oai:DiVA.org:uu-159782DiVA: diva2:447611