Elucidating the size distribution of p‑Phenylenediamine-Derived quinones in atmospheric particles

作者：Kaihui Xia, Meng Jun Qin, Mingming Han, Xianming Zhang, Xiaojun Wu, Mingyuan Liu, Shang Liu, Xinkai Wang, Wei Liu, Zhouqing Xie, Renmin Yuan, Qifan Liu · 发表于：Environment International · 年份：2025 · DOI：10.1016/j.envint.2025.109329 · 被引用次数：12 · 研究领域：Atmospheric chemistry and aerosols、Air Quality and Health Impacts、Atmospheric Ozone and Climate

Transformed from p-phenylenediamines (PPDs) antioxidant, PPD-derived quinones (PPD-Qs) have recently been recognized as emerging contaminants due to their potential negative impacts on the environment and human health. While there have been measurements of airborne PPD-Qs, the size distribution of PPD-Qs and the impact of particle size on PPD transformation chemistry remain largely unknown. Here, through the measurements of atmospheric particles in three megacities in China (Beijing, Xi'an, and Hefei), we find that PPD-Qs are widely distributed in these cities. Further analysis of the size-fractioned particles in Hefei indicates that 48 % of PPD-Qs reside in coarse particles. Given that previous studies mainly focus on the measurement of PPD-Qs in fine particles, the previously reported PPD-Q concentrations and the corresponding human exposure dosages are likely to be significantly underestimated. Furthermore, the ratio of PPD-Q to PPD concentration (PPD-Q/PPD) for particles with size range of 0.056 - 0.1 μm is up to 3 times higher than that with size range of 10 - 18 μm, highlighting the key role of particle size in determining the atmospheric oxidation reactivity of PPDs. Model simulations reveal a size-dependent pattern for the estimated concentration of particulate PPD-Qs in human body. In addition, we also demonstrate that PPD-Qs can induce the formation of cellular reactive oxygen species, suggesting that they may pose risks to human health. Overall, our results emphasi...