human health risk assessment of trace elements in drinking tap water in zahedan city, iran

Daily intake of elements through the consumption of drinking water, due to its detrimental effects, is accounted for an important concern. although the health risk assessment of heavy metals in different water sources has extensively carried out in various studies, the effect of age and the concentration of all trace elements in drinking tap water have neglected. therefore, this study was conducted to evaluate the concentrations of heavy metals, e.g., as, cd, cr, ni, pb, b, al, hg, mn, zn, cu, fe, se and ba in the drinking tap water of zahedan city and to estimate their non-carcinogenic and carcinogenic effects. moreover, this is the first research in iran that has also been dedicated to complete investigation on daily intakes of trace elements in tap water. a total of 155 samples of drinking water were randomly taken from the tap water and were analyzed using icp-oes device. the estimation of the carcinogenic and non-carcinogenic risks of analyzed elements was carried out based on the guidelines of the u.s epa. the hazard index (hi) values for children and adult age groups were 9.84e-01 and 4.22e-01, respectively. the cumulative excess lifetime cancer risk (elcr) for carcinogenic trace elements was in range of tolerable carcinogenic risk 10−6 to10−4 and for all carcinogenic elements were in the order of pb > cd > cr. it also detected that the total carcinogenic risks of the cd, as and cr in water samples through the ingestion route are at the levels of “low risk” and “low-medium risk”.