lead and cadmium content of korbal rice in northern iran

every year the entrance of factory wastes such as shiraz petrochemical complex, marvdasht sugar cube factory, and charmineh factory, and other industrial units into the kor and sivand rivers and also the entrance of the marvdasht and zarghan city sewer system wastes into the kor river and the use of their water in the cultivation of the rice has caused a significant increase in the lead and cadmium content of the grains of rice. to study the effect of the kor river's pollution on the lead and cadmium content of the korbal rice samples. the results of the study show that the lead and cadmium content of the grains of rice, 57 samples of 6 different types of rice were prepared in 19 different stations in korbal region and also 18 samples of 6 different types of rice, cultivated with unpolluted water, were prepared in the national institute of rice research (gilan). a comparison of the pollution level of the korbal and gilan rice samples shows a significant difference and indicates the significant effect of the pollution of the river on the lead and cadmium content of the korbal rice samples. the results of the study show that the lead and cadmium content of the hybrid, prolific, and late rice sample types were greater than that of unprolific and early types, such that the amount of these two elements were highest in the hassani type (the lead content was 0.9625 ppm and the cadmium content was 0.0793 ppm), whereas the gasroddashti type which blooms earlier and is long seeded has the lowest amount of these two elements.