Introduction & Objective: Heavy metals are major pollutants that can spread in the atmosphere with particulate matter and dust and because of the toxic and carcinogenic effects, their measurement and control is very important. Therefore, this study was conducted to assess Co, Cr and Mn concentration in the atmospheric dry deposition collected from Hamadan city in 2014.    

Materials & Methods: After collection of 12 dust samples from 3 sampling stations and their laboratory preparation, metals concentrations were determined using ICP–OES. All statistical analyses were performed using the SPSS statistical package.

Results: The results showed that the minimum and maximum mean concentrations of Co were 0.19 and 0.29 mg/kg for high and low traffic intensity sampling stations, respectively. The min and max mean concentrations of Cr were 0.65and 1.02 mg/kg for high traffic intensity and suburb sampling stations, respectively and the min and max mean concentrations of Mn were 7.23and 8.82 mg/kg for high and low traffic intensity sampling stations , respectively. Also comparing the mean concentrations of assessed metals with WHO permissible limits showed a significant difference (P< 0.05). The mean concentrations of metals were significantly lower than the maximum permissible limits.

Conclusion: Although the mean concentrations of Co, Cr and Mn are  lower than the  standard levels, lack of continuous monitoring of heavy  metals concentrations in the dust and particulate matters in  the air  can lead to the entrance of various types of toxic pollutants such as heavy metals into the air and result in adverse health effects.