Early-life indoor environmental exposures and COVID-19 outcomes in Chinese preschool children: A secondary analysis of a multicenter study.

Abstract

Background: Indoor environmental factors during early life may influence susceptibility to respiratory infections, but their relationship with COVID-19 outcomes in children and parents remains unclear.

Objectives: This study investigates associations between early-life household exposures (fuel type, heating methods, ventilation patterns, redecoration, dampness/mold, incense, and mosquito coil use) and COVID-19 infection and sequelae in children and their parents.

Methods: We conducted a multicenter survey among 20,012 preschool children and their parents (total 60,036 participants) from nine cities in China between December 2019 and May 2023. Logistic regression models were applied, adjusting for sociodemographic and environmental covariates. Sensitivity analyses included adjustment for outdoor air pollutants and climatic factors.

Results: Household factors such as solid fuel use, insufficient ventilation, and indoor dampness/mold were associated with higher odds of COVID-19 infection among children and parents. Use of mechanical ventilation and clean heating systems were associated with lower odds. Associations with long COVID (n = 20 child cases) were exploratory and imprecise.

Conclusions: Indoor household exposures may influence COVID-19 outcomes in children and parents, independent of outdoor air pollution. These findings highlight the potential of improving indoor environments as a preventive measure, but longitudinal studies with clinical verification are needed.