the assessment of chemical quality of drinking water in hamadan province, the west of iran

background: the aim of present work was to evaluate the drinking water quality from various regions including both urban and rural areas of hamadan province, western iran. methods: in this cross-sectional descriptive study, the samples were collected for a periods of 12 months between january 25, 2014 and january 25, 2015 from frequently used household taps as well as from municipal and communal water supplies. the main parameters investigated were nitrate, fluoride, ph, turbidity and chlorine. results: the maximum and minimum values for nitrate concentrations were measured as 140.80 mg/l and 1.56 mg/l, respectively. nitrate and fluoride content of samples were higher in wet season than in dry season and their concentration was higher in rural areas rather to urban areas. on average, fluoride contents in both urban and rural areas were well compliance with the who guidelines. the ph of all samples of the study regions was in the ranges of 6.25 to 8.41 that were in the standard ranges. twenty three percent of total samples were exceeded iranian standards of one ntu for turbidity. conclusions: the groundwater of the study area is presently having not serious health risks. however, regarding that disinfection efficiency adversely is affected by turbidity, particular attention and more programs for regular monitoring has to be done, which will not always be done in all regions.