Simulation on asphalt-related VOCs and risk analysis during pavement construction

This study aims to develop and preliminarily demonstrate a CALPUFF-based modeling framework for simulating the dispersion of volatile organic compounds (VOCs) emitted during asphalt pavement construction. The framework integrates field sampling, species-level VOCs identification and risk assessment, and dispersion modeling under real-world meteorological conditions. By combining OFP- and SOAP-based screening with simulation outputs, nine high-risk VOCs species were identified. Among them, m-diethylbenzene and 1,2,3-trimethylbenzene consistently exhibited high contributions to both ozone formation potential (OFP) and secondary organic aerosol potential (SOAP) across all construction processes, making them priority targets for emission control. The simulation results revealed that wind speed, temperature, and relative humidity significantly influence VOCs dispersion, with low wind and high temperatures promoting pollutant accumulation. A temporal analysis within 24 h post-construction revealed an initial increase followed by a sharp decline in VOCs concentration, driven by changing meteorological conditions. The comparison between simulated and measured concentrations showed a good correlation (R 2 = 0.813), supporting the applicability and robustness of the proposed framework rather than representing a full validation. These findings provide a scientific basis for optimizing construction schedules and implementing targeted emission reduction strategies. • Field sampling and GC-MS identified VOCs emitted during asphalt construction. • Nine high-risk VOCs were identified based on OFP and SOAP. • CALPUFF simulated VOCs dispersion under real-world meteorological conditions. • Wind, temperature, and humidity strongly influenced VOCs dispersion. • Simulations showed strong agreement with field data (R2 = 0.813).