Multiphase emissions from rubber modified asphalt: phase-partitioning and secondary pollutant formation potential

Rubber modified asphalt (RMA) fumes constitute a critical precursor reservoir for atmospheric pollution, posing significant risks to ecosystems. However, current knowledge remains limited regarding the multiphase emissions in RMA fumes and its environmental impacts of phase-shifting dynamics. The results demonstrate that RMA emissions undergo temperature- and CR content-dependent phase shifting, which in turn drive distinct secondary pollutant formation and inhalation exposure potential. Specifically, we introduced a quantitative phase-shifting index to characterize multiphase partitioning behavior. By integrating emission intensity and phase shifting with ozone formation potential, secondary organic aerosol formation potential (SOAFP), and respiratory deposition potential, we identified a critical transition temperature, which dominant mechanism of SOAFP transitions from gas-phase dominance toward coupled gas–liquid contributions. Correspondingly, the liquid-phase contribution to SOAFP increases to 44–49%. These findings provide new insights into how reshape fume emission, establishing a mechanistic framework to support the sustainable formulation of RMA and development of high-temperature emission control strategies.