The distribution and transport of polycyclic aromatic hydrocarbons (PAHs) in urban environments are influenced by both anthropogenic sources and natural landscape features. While previous research has primarily focused on human activities as drivers of PAH pollution, the role of terrain-especially in cities with complex topographies-remains underexplored. To investigate the effect of terrain features on PAH distribution and transport, we analyzed topsoil samples evenly distributed in Chongqing, a city with hilly terrain (elevation: 48-2300 m). PAH concentrations (Σ