title: Carcinogen Risk Assessment of Polycyclic Aromatic Hydrocarbons in Drinking Water, Using Probabilistic Approaches.
abstract: BACKGROUND
  This study was focused on the probability of carcinogen risk of low-level ingestion and dermal exposure with polycyclic aromatic hydrocarbons (PAHs) from drinking water in Tehran, capital of Iran.
  
  
  METHODS
  Concentrations of 16 PAHs were measured in the tap, bottled and heated tap water in four different seasons. Using a questionnaire-based 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.
  
  
  RESULTS
  The lifetime average daily dose and the dermal absorbed dose were 0.69E-06 and 1.33E-05 mg/kg/day, respectively. The total estimated excess lifetime cancer risk (ELCR) of ingestion and dermal exposure were 1.57E-05 and 17.24E-05.
  
  
  CONCLUSIONS
  Sum of estimated ingestion and dermal ELCR was 18.81E-05, 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 (Pspearman>0.92) and washing activities (Pspearman>0.95) had the greatest correlation on the cancer risk.
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Qazvin University of Medical Sciences, Qazvin, Iran; Center for Water Quality Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Karyab
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Masud
authors.initials: M
authors.lastname: Yunesian
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Nasseri
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Noushin
authors.initials: N
authors.lastname: Rastkari
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Amirhosein
authors.initials: A
authors.lastname: Mahvi
authors.affiliation: Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Nabizadeh
keywords: Drinking water; Iran; Risk assessment; Uncertainties