Effect of indoor air quality of day care centers in children with different predisposition for asthma

BackgroundScarce 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. MethodsIn 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. ResultsWe 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 CO2 concentration (increments of 200ppm) and diagnosis of asthma (OR: 1.10; 95% CI: 1.00-1.20). Each increment of 100g/m(3) of total volatile organic compounds (TVOC) and 1g of Der p1/g of dust were associated with wheezing in the previous 12months (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. ConclusionsIAQ in DCC seems to be associated with wheezing, in children with and without predisposition for asthma.