Indoor air pollutants in schools: nasal patency and biomarkers in nasal lavage.
BACKGROUND
There is growing concern about the respiratory health aspects of the indoor air quality in schools.


METHODS
A standardized investigation, including nasal lavage (NAL), measurement of the nasal cavity by acoustic rhinometry, and hygienic measurements of airborne pollutants, was performed in classrooms, outside the pollen season. All 279 school personnel working in the main buildings of 12 randomly selected primary schools in an urban community in central Sweden (Uppsala) were invited to enroll in the study; 234 (84%) participated. Eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme, and albumin were analyzed in NAL fluid. Crude statistical analysis, as well as multiple regression analysis, was performed, controlling for room temperature, age, sex, current smoking, and a history of atopy.


RESULTS
Most classrooms (83%) did not meet the Swedish ventilation standards. A lower degree of nasal patency was found at higher concentrations of respirable dust, nitrogen dioxide (NO2), formaldehyde, and total molds, and in the presence of Aspergillus spp. in the classroom air. The most consistent findings were observed for formaldehyde, NO2, and Aspergillus spp., related to both decreased nasal patency and increase of ECP and lysozyme in NAL. The presence of yeast was associated with an increase of ECP and lysozyme in NAL, but was not related to nasal patency.


CONCLUSIONS
Ventilation flow was below current hygienic standards in the classrooms. Air pollutants in the classroom air may influence nasal patency and inflammatory response in the nasal mucosa.
Norbäck
D
D
Department of Medical Sciences/Occupational and Environmental Medicine, University of Uppsala, University Hospital, Sweden.
Wålinder
R
R
Wieslander
G
G
Smedje
G
G
Erwall
C
C
Venge
P
P
D000393:Air Pollutants / Q000032:analysis; D016902:Air Pollution, Indoor / Q000009:adverse effects; D000418:Albumins / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis; D003430:Cross-Sectional Studies; D047091:Eosinophil Granule Proteins; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D008875:Middle Aged; D009113:Muramidase / Q000032:analysis; D009296:Nasal Cavity / Q000502:physiology*; D017817:Nasal Lavage Fluid / Q000737:chemistry*; D009195:Peroxidase / Q000032:analysis; D012123:Pulmonary Ventilation; D012260:Ribonucleases; D012574:Schools; D013548:Sweden
D000393:Air Pollutants; D000418:Albumins; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D009195:Peroxidase; D012260:Ribonucleases; D009113:Muramidase