Internal Exposure Risks of Particle-Bound Polycyclic Aromatic Hydrocarbons with an Hourly Time Resolution to Humans in Beijing

Polycyclic aromatic hydrocarbons (PAHs) are critical atmospheric pollutants known to adversely impact human health. While internal exposure assessments of PAHs have gained increasing attention, current methods lack the time resolution necessary to capture dynamic changes and chronic health effects accurately. Here, we develop an integrated approach to improve the accuracy of internal exposure assessments by combining the Multiple-Path Particle Dosimetry model, a Physiologically Based Toxicokinetic model, and high-resolution concentrations of particle-bound PAHs. The rolling mode can calculate hourly internal exposure of particle-bound PAHs, accounting for both the temporal variations of ambient PAH concentrations and their bioaccumulation in the body. The annual hazard quotient (HQ) and cancer risk (CR) based on the internal exposure are 5.86 × 10^-2 and 5.52 × 10^-6, significantly higher than the values (1.40 × 10^-3 and 4.51 × 10^-8) obtained via the conventional external exposure methods. Internal exposure and health risks (HQ and CR) are subtle to time resolution, e.g., the coarser time resolution results in a smaller internal exposure, leading to an underestimation of chronic health risks by the conventional method. Our results offer a tool for accurately assessing the health risks of particle-bound pollutants, providing valuable insights for public health policies aimed at reducing environmental risks.