Personal and microenvironmental concentrations of particles and microbial aerosol in relation to health symptoms among teachers.

A total of 81 randomly selected elementary school teachers participated in two sampling campaigns conducted 2 weeks apart during the winter. A 24-h sample collection was performed using personal and microenvironmental sampling from homes, and an 8-h sample collection was performed from workplaces of the studied subjects. Filters were analyzed for particle mass, absorption coefficient of the filter, and for both total and viable microorganisms. Comprehensive questionnaire responses were collected from the teachers concerning weekly occurred symptoms during the previous 12-month period, and they filled in symptom diaries immediately after each sampling campaign concerning symptoms during the previous 24-h and 7-day periods. The effect of different recall periods on agreement between questionnaire responses was assessed. Factor analysis was used in order to identify factors explaining the pattern of correlations within the personal, home, and work measurements. Moreover, associations between personal, home, and work measurements of pollutants and symptoms were analyzed using general estimation equations. The recall period of 7 days seemed to provide the most reliable data for the health effect assessment. Information from the factor analysis may allow reduction of variables related to the exposure assessment, and better interpretation of results. Both personal exposure and concentrations of pollutants at home were more frequently associated with health symptoms than concentrations at work. In multipollutant analyses, absorbance coefficient was positively associated with eye symptoms, and total bacteria with both cough and blocked nose.