Potentially toxic element contamination of drinking water consumed in Cappadocia region (Turkey) and health risk assessment

In this study, the concentrations of anions and potentially toxic elements in thirty-four drinking water samples consumed in the Nevsehir province located in the Cappadocia region were determined to assess their chemical quality for human consumption using an ion chromatography system and inductively coupled plasma optical emission spectrometer. The average concentrations of Cl, F, NO3, and SO42 analysed in tap and bottled drinking water samples were found as 19,485, 521, 31,840 and 34,456 mu g L-1 and 2290, 35, 2631 and 5242, mu g L--1,L- respectively. The average concentrations of Pb, Cd, Co, Sr, Hg, Cu, Fe, Mn, Ni and Zn analysed in tap water samples were found as 5.2, 2.4, 2.4, 429.0, 1.7, 12.7, 94.7, 1.7, 1.3 and 199.5 mu g L-1, respectively. The chemical analysis results obtained were compared with permissible maximum concentrations set by the national and international regulations. The Pb concentrations analysed in two tap water samples are above the maximum concentration of 10 mu g L-1. The Hg concentrations analysed in 54% and 62% of tap and bottled drinking water samples are above the maximum concentration of 1 mu g L-1, respectively. Also, average daily dose (ADD), health quotient (HQ), and cancer risk index (CRI) were estimated for adults to assess the health hazards caused by potentially toxic elements in drinking water samples. The HQ values estimated for selected potentially toxic elements are below the risk limit of 1 and there is no significant non-carcinogenic risk to the exposed adults. The average values of CRI estimated for As in three tap water samples and Cd in tap and bottled water samples exceeded the safe index range and these elements can pose a significant carcinogenic risk to the exposed adults.