The study of human exposure to environmental PAH pollution sources identified the age-specific potential cancer risks. Recognition of the importance of inhalation cancer slope factor and particle-bound PAH-to-skin
adherence factor in PAH exposure led to the efforts to estimate the significance of inhalation and dermal ILCRs. Sensitivity analysis indicates that to increase the accuracy of the results efforts should focus on a better definition of probability distributions for inhalation cancer slope factor and particle-bound PAH-to-skin adherence factor. Given the scarcity of data, most of the probability distributions were based on US EPA data,and this may be a limit to the validity of the case presented.