This thesis presents a comprehensive analysis of the globalhealth impacts of polycyclic aromatic hydrocarbons (PAHs) in ambient air,conducted on the basis of a high-resolution emission inventory, global chemicaltransport modeling, and probabilistic risk assessment. One of the mainstrengths of the thesis is the concentration downscaling process, whichprovides a linkage between emissions and exposure concentrations at acomparatively high resolution. Moreover, by focusing on individual susceptibility,the thesis proposes an instrumental revision of current risk assessmentmethodology and argues that, if individual susceptibility were not taken intoconsideration, the overall risk would be underestimated by 55% and theproportion of highly vulnerable populations would be underestimated by morethan 90%.