Probabilistic Simulation of Incremental Lifetime Cancer Risk of Children and Adults Exposed to the Polycyclic Aromatic Hydrocarbons – PAHs in Primary School Environment in Serbia, Model Development and Validation

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are considered to be major air pollutants with a strong negative influence on human health. Many of them are toxic with high carcinogenic potential. Children and school staff spend a significant portion of daytime at schools, mostly indoors. Therefore, the hypothesis can be made that air quality significantly impacts their health. A health risk assessment, performed by calculating Incremental lifetime cancer risk (ILCR), was conducted in the framework of this study. Indoor and outdoor PAHs concentrations were measured in typical Serbian primary school. Total suspended particles (TSP) and gas-phase PAHs from the air were collected both inside the school building and in the outside school environment. Average indoor and outdoor PAHs concentrations were used to calculate benzo[a]pyrene equivalent (BaPeq) concentration. A significantly higher BaPeq was observed in the gas-phase than in the TSP, due to a high amount of low molecular PAHs present in the gas-phase. The measured BaPeq concentration values were fitted to the appropriate mathematical distribution and used as an input parameter for stochastic ILCR modeling. Different body weight and inhalation rate distributions were used for sampling during ILCR calculations. The performed sensitivity analysis showed that the two different recommended values of cancer slope factor had a major impact on the ILCR values. Based on this, it was decided to perform simulations using cancer slope factors for individual PAHs. The obtained ILCR values for both children and adults were greater than the allowed level, indicating high potential lung cancer risk. It may be concluded that it is necessary to improve indoor air quality in schools applying measures for lowering TSP PAHs with high carcinogenic potential.