health risk assessment of fe, mn, cu, cr in drinking water in some wells and springs of shush and andimeshk, khuzestan province, southern iran

background: in the current study,the hazard quotient, the hazard index (hi) and spatial variations of fe,mn,cu and cr in drinking water sources of andimesk-shush, khuzestan province, southern iranaquifer were assessed. methods: we compared theconcentrations of aforementioned heavy metals in wells and springs inandimeshk and shush regions. the non-carcinogenic risk assessment of heavy metals was implemented usingunited states environmental protection agency (usepa) index.the spatial maps in the area were developed by geostatistical methods. results: mean concentrations of heavy metals in groundwater sources of the study area in decreasing order was as follows: cu >mn> fe> cr. except for iron,mean heavy metal concentrations were higher than the standard levels. manganese concentration in 41.5% of the samples exceeded the permissible limits. copper was higher than the safety limit in 74% of the samples, and chromium in 54% of the cases. the spatial pattern of heavy metals concentrations indicated higher concentrations in the southern parts of the region. the mean hazard quotients of most samples for the four heavy metals were lower than one, indicating that there was no immediate threat due to the exposure to these heavy metals.  the calculated accumulated hazards of these heavy metals produced different results, with hazard indices of higher than one. conclusion: the accumulated hazard indicesfor the evaluated metals were higher than one, indicating that chronic ingestion of these waters threatens the health of local consumers on the long run.