Journal
Journal of Hazardous Materials, 509, 141991 (2026)
Real-time characterization of gas- and particle-phase emissions from asphalt mixtures, investigating how reclaimed asphalt pavement (RAP) incorporation and production temperature influence the composition and levels of emitted organic compounds.
Scientific Abstract
Asphalt production generates fumes classified by the IARC as possibly carcinogenic (Group 2B), containing a wide range of volatile and semi-volatile compounds, including polycyclic aromatic hydrocarbons (PAHs) and their derivatives. As the incorporation of reclaimed asphalt pavement (RAP) increases to meet circular economy goals, uncertainties remain regarding the influence of aged or potentially contaminated binders on emissions due to limited road traceability. While offline analytical methods provide detailed molecular information, they remain limited when addressing exposure-relevant aspects, highlighting the need for real-time measurements. In this study, a pilot-scale mixing system simulating asphalt production under controlled conditions was used to investigate six formulations (virgin aggregates or a mixture of virgin aggregates and RAP) at 140 °C and 160 °C. Emissions were monitored by an SMPS coupled to a PTR-ToF-MS operated either in standalone mode or coupled to a Charon inlet, enabling real-time characterization of gaseous and particulate organic species, respectively. A total of 43 compounds were assigned and quantified based on their mass spectra, providing a detailed overview of emitted VOCs, PAHs, and PAH derivatives. Increasing the temperature from 140 °C to 160 °C resulted in higher emission levels, particularly for high-molecular-weight PAHs and PAH derivatives. RAP-containing mixtures also exhibited higher emissions and a broader particle size range (100–400 nm) compared to mixtures made of virgin aggregates. This study demonstrates that both RAP and temperature significantly influence emission levels and composition, highlighting the value of online analysis for understanding asphalt emissions in future assessments of occupational exposure.
