Evaluating the spatial distribution of quantitative risk and hazard level of arsenic exposure in groundwater, case study of Qorveh County, Kurdistan Iran

Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of iran’s kurdistanprovince is considered. to investigate the potential risk and hazard level regarding arsenic-contaminated drinkingwater and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of qorvehcounty were considered for evaluation of arsenic concentration in water. sampling campaign was performed inaugust 2010 and arsenic concentration was measured via the silver diethyldithiocarbamate method. the highestand lowest arsenic concentration are reported in guilaklu and qezeljakand villages with 420 and 67 ?g/l,respectively. none of thirteen water samples met the maximum contaminant level issued by usepa and institute ofstandards and industrial research of iran (10 ppb). the highest arsenic concentration and consequently risk andhazard levels belong to villages situated alongside the eastern frontiers of the county. existence of volcanicactivities within the upper miocene and pleistocene in this part of the study area may be addressed as the maingeopogenic source of arsenic pollution. quantitative risk values are varying from 1.49e-03 in qezeljakand to8.92e-03 in guilaklu and may be interpreted as very high when compared by similar studies in iran. regardingnon-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic dailyintakes are greater than arsenic reference dose. such drinking water source has the potential to impose adversecarcinogenic and non-carcinogenic effects on villagers. accordingly, an urgent decision must be made to substitutethe current drinking water source with a safer one.