Investigation of the exposure risk of TEX released from outdoor synthetic rubber tracks to adolescents of different heights.

Toluene, ethylbenzene, and xylene (TEX) are the primary pollutants released from outdoor synthetic rubber tracks and can be easily absorbed in the respiratory tract and skin, leading to harmful health effects. Exploring the mass transfer characteristics of TEX emitted from tracks and its effects on adolescents at different heights is thus important. In this study, the key emission parameters were determined via environmental chamber experiments. A solid-gas two-phase mass transfer model for a semiunbounded region was developed to describe the emission behaviour of TEX from four different types of tracks. The problem of unbounded regions was converted into a bounded region problem via the artificial boundary method combined with Laplace transforms. Based on numerical simulation techniques, the spatiotemporal distribution profiles of outdoor TEX concentrations were predicted, which revealed significant differences compared with the concentration in the environmental chamber. Additionally, the TEX exposure concentration for preschool children is about 3 times greater than that for university students. By comparing the release characteristics of four different types of synthetic rubber tracks, it was found that the full rubber track exhibited the highest levels of TEX emissions. These results lay the groundwork for understanding the transport characteristics of TEX emissions from outdoor rubber tracks and provide valuable data for health risk assessments of adolescent populations.