To cite this article: Carreiro-Martins P, Papoila AL, Caires I, Azevedo S, Cano MM, Virella D, Leiria-Pinto P, Teixeira JP, Rosado-Pinto J, Annesi-Maesano I, Neuparth N.Effect of indoor air quality of day care centers in children with different predisposition for asthma. Abstract 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 (P 25 -P 75 : 25-58) months. Considering the overall sample, in the first questionnaire, associations were found between CO 2 concentration (increments of 200 ppm) and diagnosis of asthma (OR: 1.10; 95% CI: 1.00-1.20). Each increment of 100 lg/m 3 of total volatile organic