Investigating mercury contamination in some of the wild birds in Isfahan city and Zayandehroud River

Mercury is one of the most toxic heavy metals with the characteristic of accumulation and bio-magnification in food chains. Isfahan is an important industrial province in Iran with various sources of mercury contamination. However، biological monitoring of mercury in the environment has yet to be conducted. Birds، which are exposed to mercury by different ways، including direct contact with contaminated water and food، are good biological indicators. The aim of this study was to investigate mercury contamination in some of the wild birds in Isfahan city and Zayandehroud River. The effect of trophic levels on the bioaccumulation of mercury in the body of these birds was explored. 40 samples of birds were collected in different areas and the amount of mercury was measured in kidney، liver and hyperpnea، using cold vapor atomic absorption spectrometry. Amongst the three organs، hyperpnea showed the highest amount of mercury with the average amount of 2002. 3 ppb and kidney showed the lowest with the average of 1284 ppb. Animal consuming birds accumulated more mercury in their tissues and vegetarians showed the lowest value. The results indicated the presence of mercury in Isfahan environment، therefore، it is necessary to monitor and manage heavy metals in the environment including Zayandehroud River.