Late Breaking Abstract - Association between Volatile Organic Compounds (VOCs) concentrations in daycares and child wheeze in the French CRESPI cohort

<bold>Background:</bold> Concern is increasing about of the role of poor Indoor Air Quality in respiratory disorders such as asthma, especially in children. While the deleterious respiratory health impact of some volatile organic compounds (VOCs) in the home environment has been suggested, the health impact of VOC concentrations in daycares has never been investigated. <bold>Methods:</bold> This cross-sectional study included 532 children (mean age: 22.3 months; 47.4% female) of the French CRESPI cohort (106 daycares, 2019-2022). 67 VOCs were measured during one day and concentrations were studied in 4 categories based on quartiles. Three child wheezing outcomes (ever wheeze since birth, recurrent wheeze (≥ 3 times since birth), and ever wheeze with inhaled corticosteroid use) were evaluated by parental questionnaire. Associations between daycare VOC concentrations and wheezing outcomes were analyzed with Generalized Estimating Equations to account for a possible daycare effect, and adjusted for child age, parental smoking status and education level. <bold>Results:</bold> Higher concentrations of 1,2,4-trimethylbenzene (Odds Ratio for Q4 vs. Q1, 95% CI:1.56, 1.03–2.38; p-trend=0.08), 1-methoxy-2-propylacetate (1.62, 1.08-2.40; p=0.01), decamethylcyclopentasiloxane (2.12, 1.29-3.48; p=0.004) and methylisobutylcetone (1.85, 1.29-2.67; p<0.001) were associated with ever wheeze, with similar findings for all wheezing outcomes. After correction for multiple testing, a significant trend remained for methylisobutylcetone. <bold>Discussion:</bold> Daycare exposure to specific VOCs was linked to increased wheeze risk in children. Further efforts to reduce indoor pollutant concentrations and limit sources are needed.