1 Hospital de Dona Estefânia, Immunoallergy, Lisbon, Portugal
2 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, CEDOC, Lisbon, Portugal
3 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, Pathophysiology, Lisbon, Portugal
4 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, Informatics and Biostatistics, Lisbon, Portugal
5 Centro Hospitalar de Lisboa Central, EPE, Gabinete de Apoio Estatístico e Epidemiológico, Lisbon, Portugal
6 Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
7 Laboratório Nacional de Engenharia Civil, Lisbon, Portugal
8 Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Lisbon, Portugal
9 Hospital da Luz, Lisbon, Portugal
XXXII Reunião anual da EAACI. Milão, Junho de 2013
Background: Almost half of the children have at least one episode of wheezing before six years of age. Poor indoor air quality (IAQ) at day care centers (DCC) has been proposed has a risk factor for wheezing. Our aim was to study the wheezing incidence in two clusters of DCC, different in what concerns to IAQ.
Methods: In the scope of ENVIRH study (Environment and Health in children day care centers - PTDC/SAU-ESA/100275/2008) 19 DCC from Lisboa and Porto were selected. Stratified sampling followed by cluster analysis, to guarantee the heterogeneity of DCC concerning IAQ, was used. The selection was performed after an IAQ assessment at the end of 2010 in a larger number of DCC. A new IAQ assessment in those 19 DCC was performed at the end of 2011, with measurements of CO2, CO, volatile organic compounds (VOCs), PM10, indoor air temperature (IAT) and relative humidity (IRH). A questionnaire addressing wheezing symptoms was distributed (n= 1229). Hierarchical and logistic models were used for data analysis.
Results: From the 583 questionnaires considered in the analysis, 54% were boys and the mean age was 38 months (SD ± 19 months). At the end of 2011, one of the clusters had higher values of CO2 (p< 0.001) and VOCs (p=0.021), lower IAT (p=0.037) and higher IRH (p=0.008). No differences were found between clusters for PM10 (p=0.585). In the multivariable analysis, only age (OR: 0.97, CI 95%: 0.96 - 0.98, p < 0.001) and belonging to the worst IAQ cluster (OR: 1.45, CI 95%: 1.01 - 2.04, p = 0.042) were associated with wheezing (45.6% in the worst IAQ cluster vs 36.6% in the other cluster).
Conclusion: Attending DCC with poor IAQ was a risk factor for wheezing. More attention should be dedicated to improve IAQ standards in DCC.
Keywords: Indoor air quality, day care centers, wheezing, children