Introduction & Objective: Heavy metals are the most harmful contaminants found in drinking water supplies that can lead to serious damage to metabolic, physiological and body structures. Industrial activities like production and storage of sewage spills and improper disposal of industrial wastes as well as the exhaustion of the distribution network and the home network can cause the release of heavy metals in the drinking water. Therefore, the  measurement of these elements at the point of use is necessary.

Material & Methods: This cross-sectional study assessed the amount of lead,chromium, and zinc in the drinking water of Hamadan City  in the winter of 1393 which can increase the risk of getting non-cancer diseases Stratified random sampling was conducted to measure the samples concentration by atomic absorption (Perkin Elmer, AAS-PEA-700 model). In order to carry out the risk characterization and sectional exposure assessment, the US EPA (Environmental Protection Agency of America) were used.

Results: The results showed that the average concentration of lead, chromium and zinc at the point of use of surface water resources, 10.927, 2.246 and 1305.604 the underground 19.301, 11.085 and 1613.709and mixed 20.085, 11.563 and 1299.844 , respectively and the average of exposure to risk  of children is 0.078 and  of adults are 0.047and lead risk index was HQ<1 for all ages. Zinc and chromium had 31.7 percent risk for < 1month and 1-3 month age group and exposure to zinc and chromium, higher than the 0.3, have been 0.003, respectively.

Conclusion: 41.46 percent of the samples contained Lead concentration higher than WHO standards and Industrial Research of Iran Institute of Standards and 39.02 percent of the samples had concentrations above the EPA standard. None of the samples  had sectional risk for children and adults. Although the amount of chromium and zinc was sub-standard, because they are  highly disease producing, the risk in the two  following age groups increases  :  < 1month and 1-3 months. Therefore, sub-standard concentration does not mean that there is no risk.

(Sci J Hamadan Univ Med Sci 2016; 23 (1):25-33)