Nasal patency and lavage biomarkers in relation to settled dust and cleaning routines in schools

Objectives This study determined the relations between settled dust and cle aning routines in classrooms on one hand, and nasal symptoms, nasal cavity dimensions, and the concentration of selected biomarkers of inflammation in nasal lavage on the other. Methods Measurements of settled dust via standardized vacuum cleaning and a n investigation of the cleaning routines were performed in 12 randomly sele cted primary schools in the municipality of Uppsala. Clinical examinations including acoustic rhinometry and nasal lavage were performed in the school environment among 279 school personnel working in the main buildings of th e schools. Eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozy me, and albumin were analyzed in the lavage fluid. The relationships betwee n the medical and hygienic data were analyzed both bivariately and with a m ultiple regression model controlling for age, gender, smoking, atopy, room temperature, and urban vicinity of the school. Results The amount of settled dust was positively related to subjective nas al obstruction and smaller nasal cavity dimensions measured with acoustic r hinometry. The noses were less patent, and the levels of ECP or lysozyme in the lavage were increased for the subjects in schools with a lower frequen cy of floor mopping, a lower frequency of desk cleaning, and where wet mopp ing was used. Conclusions Our results indicate that the actual dust levels in Swedish cla ssrooms can affect the occurrence of nasal obstruction among school personn el. A beneficial effect on the clinical signs of the nasal mucosa was obser ved for a higher frequency of both floor mopping and desk cleaning, whereas the use of wet mopping seemed disadvantageous in comparison with dry moppi ng. These findings illustrate the need for adequate cleaning procedures to minimize the environmental effects on the airway mucosa.