Residential VOC from building materials: Exposures, health risks, and ambient hazards

Indoor volatile organic compounds (VOCs) from building materials are a significant concern in China, yet their national indoor exposures, health risks, or impact on the ambient remain underexplored. Based on the emission mechanism and measurements of 53 VOC species in 279 residences across 9 cities, we correlated their indoor concentrations with temperature, humidity, ventilation, loading factor and renovated time. Using Monte Carlo method, we estimated average residential concentrations and health risks of the top 10 VOC species across 31 regions. We found significant spatial-temporal variations in residential exposures, with higher concentrations in the south and during summer generally. Residential VOC emissions significantly affect the ambient. Nationally, formaldehyde, 1,2-dichloropropane, and cumene from residential building materials contributed 13.169 %, 14.779 %, and 2.475 % of total anthropogenic emissions to the ambient, respectively. Urban emissions were higher than rural; for instance, urban formaldehyde emissions were 2.55 times of the rural emissions. Residential VOC contribute to the ambient potential to form ozone and secondary organic aerosols, surpassing emissions from about half of the 98 previously studied anthropogenic sources. Our results underscore the urgency of reducing residential VOC levels, particularly in urban areas, to promote sustainable development by addressing both direct indoor health effects and broader environmental impacts.