investigation and comparison of mercury (hg) content and its weekly intake by body in some imported and iranian kinds of rice

this study has paied to investigation and comparison of content hg in imported rice from indian country and cultivated rice (oryza sativa( in borojerd and isfehan provinces in iran. 30 types of indian imported rice and 5 type iranian rice available in market of iran in 4 repeat from every type. the first step, grains of raw rice were digested by acid digestion method and then were analyzed for hg by adsorption atomic. to assess the weekly intake of hg by rice, from daily consumption of rice was calculated. and it was compared with the provisional tolerable weekly intake (ptwi) established by who. the results showed that average concentration of hg in imported rice was 2.16 ng/g dry wt and ranged from 1.12 to 3.96 ng/g dry wt, as average concentration of hg in iranian rice was 0.4 ng/g dry wt and ranged from 0.03 to 0.89 ng/g dry wt. so the hg content in the imported and iranian rice samples were found below the limit of standard recommended by the chinese national standard agency. also average weekly intake of hg from imported and iranian rice respectively were 41 ng/kg body weight/week that ranged from 38 to 45 ng/kg body weight/week and 8 ng/kg body weight/week that ranged from 5.9 to 9.6 ng/kg body weight/week that were below the maximum weekly intake recommended by who and approximately were equal with 0.082% and 0.016% ptwi recommended by who. to perform test of mean comparison identified that there are different significantly between content hg in iranian and imported rice in level 5% and average contents heavy metal hg in imported rice were significantly (p