Evaluation of estimated daily intake (EDI) of cadmium and lead for rice (Oryza sativa L.) in calcareous soils

The excessive amounts of cadmium and lead in food chain can cause health problems for humans and ecosystem.rice is an important food in human diet. therefore this study was conducted in order to investigate cadmium andlead concentrations in seed rice (oryza saliva) of paddy fields in southwest of iran. a total of 70 rice seed sampleswere collected from paddy fields in five regions of khuzestan province, southwest iran, during harvesting time. inthe samples cadmium and lead concentrations were measured. to assess the daily intake of cadmium and leadby rice, daily consumption of rice was calculated. the results showed that average concentrations of cadmium andlead in rice seeds were 273.6 and 121.8 ?g/kg, respectively. less than 72% of rice seed samples had cadmiumconcentrations above 200 ?g/kg (i.e. guide value for cadmium); and less than 3% had lead concentrations above150 ?g/kg (i.e. guide value for lead). the estimated daily intakes of cadmium by the local population wascalculated to 0.59 ?g/day kg bw, which corresponds to 59% of the tolerable daily intakes (i.e. 1 ?g/day kg bw).eleven out of 70 samples (15.71%) exceed the tolerable daily intakes. the dietary intakes for lead in the localpopulation ranged from 0.22 to 0.47 ?g/day kg bw. tolerable daily intakes for lead is 3.6 ?g/day kg bw. as awhole, long term consumption of the local rice may bear high risk of heavy metal exposure to the consumer in thestudy region.