Health risk assessment via Monte Carlo simulation and sensitivity analysis for fluoride and nitrate content in bottled waters consumed in Kermanshah city, Iran

Bottled water consumption has increased in recent decade due to many reasons, especially significant decline in water quality and quantity. The concentration of fluoride and nitrate in bottled waters may vary based on brands and locations. This study was carried out to determine the levels of fluoride and nitrate in bottled waters consumed in Kermanshah city and assess the related non -carcinogenic risks. Totally, 22 brands of bottled water were collected from markets. Fluoride and nitrate measurement was conducted via a UV-visible spectrophotometer (DR-5000). From the results, Fluoride and nitrate levels in the studied bottled waters were 0.32 +/- 0.18 mg/L and 2.3 +/- 1.41 mg/L, respectively. The risk of non-carcinogenic in term of HQ for fluoride exposure, for only 2 brands of bottled water were > 1 for infants group. HQ was less than 1 for nitrate in all the brands for all the age groups revealed non-carcinogen risks. Hazard index (HI) calculation showed that only in 2 brands of bottled water HI was > 1 for infants group. The HI were as infants (0.64) > children (0.36) > teenagers (0.27) > adults (0.24). From Monte Carlo simulation, 95th Percentile for nitrate and fluoride was less than 1 for all the groups. This result indicated non-carcinogenic risks of nitrate and fluoride for 95% of the studied groups. Moreover, sensitivity analysis showered that concentration for both nitrate and fluoride had the highest effect on HQ for all the groups. From this work, although fluoride and nitrate content in the bottled waters were at standard range, but infants were proportionally at higher risk.