RESUMEN
BACKGROUND: Scarce information is available about the relationships between indoor air quality (IAQ) at day care centers (DCC), the estimated predisposition for asthma, and the actual wheezing susceptibility. METHODS: In the Phase II of ENVIRH study, 19 DCC were recruited after cluster analysis. Children were evaluated firstly using the ISAAC questionnaire and later by a follow-up questionnaire about recent wheezing. A positive asthma predictive index (API) was considered as predisposition for asthma. Every DCC was audited for IAQ and monitored for chemical and biologic contaminants. RESULTS: We included 1191 children, with a median age of 43 (P25 -P75 : 25-58) months. Considering the overall sample, in the first questionnaire, associations were found between CO2 concentration (increments of 200 ppm) and diagnosis of asthma (OR: 1.10; 95% CI: 1.00-1.20). Each increment of 100 µg/m(3) of total volatile organic compounds (TVOC) and 1 µg of Der p1/g of dust were associated with wheezing in the previous 12 months (OR: 1.06; 95% CI: 1.01-1.11 and OR: 1.06; 95% CI: 0.99-1.12, respectively). In the follow-up questionnaire, TVOC were again associated with wheezing (OR: 1.05; 95% CI: 1.00-1.11). Children exposed to fungal concentration above the 75th percentile had also higher odds of wheezing at follow-up. TVOC were associated with wheezing in children with either negative or positive API. CONCLUSIONS: IAQ in DCC seems to be associated with wheezing, in children with and without predisposition for asthma.
Asunto(s)
Contaminación del Aire Interior/efectos adversos , Asma/etiología , Guarderías Infantiles , Ruidos Respiratorios/etiología , Contaminación del Aire Interior/análisis , Preescolar , Susceptibilidad a Enfermedades , Femenino , Estudios de Seguimiento , Humanos , Masculino , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
UNLABELLED: Poor ventilation at day care centres (DCCs) was already reported, although its effects on attending children are not clear. This study aimed to evaluate the association between wheezing in children and indoor CO2 (a ventilation surrogate marker) in DCC and to identify behaviours and building characteristics potentially related to CO2. In phase I, 45 DCCs from Lisbon and Oporto (Portugal) were selected through a proportional stratified random sampling. In phase II, 3 months later, 19 DCCs were further reassessed after cluster analysis for the greatest difference comparison. In both phases, children's respiratory health was assessed by ISAAC-derived questionnaires. Indoor CO2 concentrations and building characteristics of the DCC were evaluated in both phases, using complementary methods. Mixed effect models were used to analyze the data. In phase I, which included 3,186 children (mean age 3.1 ± 1.5 years), indoor CO2 concentration in the DCC rooms was associated with reported wheezing in the past 12 months (27.5 %) (adjusted odds ratio (OR) for each increase of 200 ppm 1.04, 95 % CI 1:01 to 1:07). In phase II, the association in the subsample of 1,196 children seen in 19 out of the initial 45 DCCs was not significant (adjusted OR 1.02, 95 % CI 0.96 to 1.08). Indoor CO2 concentration was inversely associated with the practices of opening windows and internal doors and with higher wind velocity. A positive trend was observed between CO2 and prevalence of reported asthma (4.7 %). CONCLUSION: Improved ventilation is needed to achieve a healthier indoor environment in DCC.