Global health impacts of PAHs based on high-resolution modeling by dynamic simulation and relative emission downscaling

Polycyclic aromatic hydrocarbons (PAHs) are one of the highly toxic pollutants that require strict control. High-resolution distribution of PAHs is crucial for accurately quantifying their population exposure levels. However, due to the high computational cost, few models applying the dynamical approach could simulate global PAHs to evaluate health effects with resolution down to 1–10 km. This study simulated the global distribution of PAHs by combining the IAP-AACM model with a nonlinear downscaling method based on relative anthropogenic emissions and observations. A global high-resolution (0.1° × 0.1°, ∼10 km in middle latitudes) dataset of Benzo[a]pyrene (BaP, the most representative PAHs) in 2013 and 2018 is generated to support exposure studies. The 0.1° × 0.1° results are comparable to the nested simulation and have better consistency with observations than that of the 1° × 1° simulation. The 0.1° × 0.1° estimation shows significantly higher population-weighted total incremental lifetime cancer risks (PTILCR), with an increase larger than 50 %, compared to the 1° × 1° simulation. The PTILCR is greatly higher in winter than in other seasons and it is larger for children and young adults than for adolescents and seniors. The study has significant implications for the reliable assessment of global health risks of PAHs and the development of scientific management strategies for different age groups. • The 0.1° × 0.1° simulation by downscaling improves the global BaP accuracy. • Health risk due to BaP at 0.1° × 0.1° resolution has increased by over 50 %. • Health risk due to BaP is significantly higher in winter than in other seasons. • Health risk due to BaP is larger for children and young adults than for other groups.