Carcinogen Risk Assessment of Polycyclic Aromatic Hydrocarbons in Drinking Water, Using Probabilistic Approaches

lt;p gt; lt;strong gt;Background: lt;/strong gt; This study was focused on the probability of carcinogen risk of lowlevel ingestion and dermal exposure with polycyclic aromatic hydrocarbons lt;strong gt; lt;/strong gt;(PAHs) from drinking water in Tehran, capital of Iran. lt;strong gt; lt;/strong gt; lt;/p gt; lt;p gt; lt;strong gt;Methods: lt;/strong gt; Concentrations of 16 PAHs were measured in the tap, bottled and heated tap water in four different seasons. Using a questionnairebased survey, exposure with PAHs from drinking water was evaluated via direct ingestion, swimming, washing and showering. Finally, a comprehensive risk assessment was performed in four age groups. Rank correlation was used to represent variability in risk analysis and obtained coefficients were used for sensitivity analysis. In addition, Monte Carlo simulation was implemented to determine risk probability distributions and to calculate cumulative probability of the total risks in different age groups. lt;/p gt; lt;p gt; lt;strong gt;Results: lt;/strong gt; The lifetime average daily dose and the dermal absorbed dose were 0.69E06 and 1.33E05 mg/kg/day, respectively. The lt;strong gt; lt;/strong gt;total estimated lt;strong gt; lt;/strong gt;excess lifetime cancer risk (ELCR) of ingestion and dermal exposure were lt;strong gt; lt;/strong gt;1.57E05 lt;strong gt; lt;/strong gt;and lt;strong gt; lt;/strong gt;17.24E05. lt;strong gt; lt;/strong gt; lt;/p gt; lt;p gt; lt;strong gt;Conclusion: lt;/strong gt; Sum of estimated ingestion and dermal ELCR was 18.81E05, which was higher than the acceptable value recommended by WHO. It means a total of 1504 lifetime cancer cases in residents of Tehran. Monte Carlo simulation indicated that risk probability above the acceptable level was 96.2% in dermal exposure. Moreover, sensitivity analysis indicated that tap water consumption (P lt;sub gt;spearman lt;/sub gt; amp;gt;0.92) and washing activities (P lt;sub gt;spearman lt;/sub gt; amp;gt;0.95) had the greatest correlation on the cancer risk. lt;strong gt; lt;/strong gt; lt;/p gt; lt;p gt; lt;strong gt;  lt;/strong gt; lt;/p gt;