1- Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, E.P.E.;
2- Centro de Estudos de Doenças Crónicas – CEDOC;
3- Departamento de Fisiopatologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa;
4- Departamento de Bioestatística e Informática, CEAUL, Faculdade de Ciências Médicas (FCM), Universidade Nova de Lisboa, Lisboa;
5- Centro de Investigação do Centro Hospitalar de Lisboa Central, E.P.E.; 6- Instituto Nacional de Saúde Dr. Ricardo Jorge;
7- Laboratório Nacional de Engenharia Civil;
8- Departamento de Microbiologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa;
9- Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa;
10- Hospital da Luz.
- ATS 2012, San Francisco, 18 a 23 de Maio de 2012 (Poster).
Background: Many infants and preschool children experience respiratory diseases. There are several risk factors listed for wheezing and asthma diagnosis, some related with indoor's air quality.
Methods: In the scope of the ENVIRH study (Environment and Health in children day care centers) we randomly selected 46 public schools from Lisbon and Oporto. Those schools comprised nursery and pre-school in the same institution and corresponded to half of the total number of public schools in these cities. A questionnaire (derived from the ISAAC's questionnaire) was distributed to all children aged 0-5 years (n= 5161). An assessment of the day-care center's design characteristics and indoor air quality was also performed. For data analysis we used regression models that considered the structure of dependence between individuals within the same institution. Parameters of these models were estimated through Generalized Estimating Equations (GEE) with an exchangeable working correlation.
Results: 3185 questionnaires were answered (62%). From those, 50.5% concerned to boys and 49.5% to girls. The mean age was 3.1 years (SD ± 1.5 years). Concerning respiratory diseases, 27.5% (95% CI: 25.9% – 29.0%) children wheezed in the previous 12 months and 4.6% (95% CI: 3.9% - 5.3%) reported asthma diagnosis. From the several variables considered, in the multivariable analysis, only remained significant for "wheezing in the previous 12 months" the following: personal history of eczema (OR: 1.35, CI 95: 1.14 - 1.60, p <0.001),parental history of asthma or rhinitis (OR: 1.99, CI 95: 1.67 - 2.38, p <0.001) and an average increase of 100 ppm of CO2 in the classroom (OR: 1.02, CI 95: 1:01 to 1:03, p = 0.008). For asthma diagnosis, remained significant the children's age (OR: 1.27, CI 95: 1.13 - 1.43, p <0.001), parental history of asthma or rhinitis (OR: 1.83, CI 95: 1.38 - 2.43, p <0.001) and the presence of older siblings (OR: 0.56, CI 95: 0.37 - 0.84, p =0.008).
Conclusion: The levels of CO2 in the classrooms were associated with wheezing in the previous 12 months. Our findings suggest that more attention should be dedicated to day care centers indoor air quality.
Palavras-chave: wheezing, CO2, children.