Indoor Air Quality in Schools and Health Symptoms among Portuguese Teachers

ABSTRACT

The purpose of this study was: (i) to characterize the school indoor environment; (ii) to evaluate self-reported prevalence of disease symptoms among Portuguese teachers; and (iii) to evaluate, as far as we know for the first time in Portugal, the impact of the indoor air quality of schools on the prevalence of disease symptoms among teachers. The study was performed in the city of Oporto, starting in 2004; it included the analysis of questionnaires fulfilled by schoolteachers (n = 177), walkthrough surveys of schools grounds, buildings, and individual classrooms (n = 76), as well as indoor air monitoring. Respirable particle increase was related to chalk use and CO₂ concentrations widely exceeded reference values. Schools located near traffic lines presented higher benzene and toluene concentrations. The guideline for total viable microorganism concentration was exceeded in 35.6% of classrooms. Significant increases in disease symptoms among teachers could be related to poor indoor air quality, which was mainly due to inefficient ventilation and influence of traffic emissions. Statistically significant correlations were found between central nervous system injuries and the levels of CO₂ and total volatile organic compounds, and between upper respiratory problems and mucosal irritation and the levels of TVOC and respirable particles.

Key words:

• indoor air quality
• occupational exposure
• schools
• schoolteachers
• symptoms
• ventilation

ACKNOWLEDGMENT

The authors are grateful to the directors and teachers of schools for their helpful cooperation. This work was supported by Fundação para a Ciência e Tecnologia (FCT)—through POCTI/ESP/47806/2002 contract and by Programa Operacional da Saúde—Saúde XXI through SIFEC 15-01-01/FDR00126 contract.