Observation, prediction, and risk assessment of volatile organic compounds in a vehicle cabin environment

While vehicle cabin environment significantly impacts human health, systematic studies on this important microenvironment are lacking. Here, we conduct a 12-day field observation of a new car under varying environmental conditions. Concentrations of 20 common volatile organic compounds are determined. Levels of formaldehyde and acetaldehyde exceed the suggested limit, with 34.9% and 60.5% over the standard rate, respectively. By combining an improved multi-source model with quantitative correlations between three key parameters of volatile compound emissions from various in-cabin materials and temperatures, we predict formaldehyde concentrations at different temperatures, which are consistent with measurements. We find that volatile compound emission characteristics are dependent on material surface temperature rather than the widely used metric of air temperature. This study probes volatile compound variability in a realistic vehicle cabin via observation and modeling and estimates in-cabin incremental lifetime cancer risk via three exposure routes, indicating a high health risk for drivers.