Uptake of cadmium and lead by rice grown in four contaminated soils of Chittagong, Bangladesh

ABSTRACT

Rice was grown on soils collected from four different contaminated areas of Chittagong including city sewage, tannery, fertilizer factory and cement factory. Cadmium concentrations in grain of rice were 0.98, 0.10, 0.22 and 0.36 mg/kg-1 dry weight for city sewage, tannery, and fertilizer factory and cement factory soil, respectively. Cadmium concentration ranged from 2.73 to 6.91 mg/kg-1 in straw and 3.50 to 27.91 mg kg-1 in root. Lead concentration in grain, straw and root was significantly differed among the soils with the highest values [0.75, 4.13 and 39.37 mg kg-1, respectively] in city sewage soil and the lowest values [0.34, 2.16 and 29.53 mg kg-1, respectively] in tannery soil. Among different plant parts [root, straw and grain], the lowest values of Cd and Pb were observed in the grains. Almost all of the Cd and Pb absorbed by rice grain were likely to accumulate in the edible parts and Cd and Pb have not been detected in the grain chaffs. These results have implied that higher concentrations of Cd and Pb exceeding the maximum safe-intake levels [0.1 mg kg-1] in grains proposed by the FAO/WHO could result in human health problem: