هدیه بدخشان

The study was undertaken to show comparative accumulation of cadmium in different organs and the effect of ion-exchanging agent zeolite on reduction of cadmium toxicity in common carp after 15 and 30 days post exposure to low concentration of cadmium. The experiment were carried out with 45 fish were obtained from local fish farm. Fish were randomly distributed in three indoor fiberglass tanks supplied with well water. Group I were use as a control group, while the second group exposed to 30 ppb (30µg l-1) cadmium as CdCl2 and group III was exposed to 30µg l-1plus 10mg/l natural zeolite (clinoptilolite) for 30 days. Five fish were randomly removed from each tank at the days15 and 30 post exposure and organ samples including kidney, liver, gill and spleen were provided. Water quality parameter and the level of cadmium in water were measured two times weekly throughout the exposure. The cadmium accumulation in different organs and water were monitored using atomic absorption spectrophotometer. The present study shows that addition of zeolite to cadmium contaminated water; significantly (p≤0.05) reduces the metal level in examinant tissues after 30 days. Following 30 days exposure the cadmium accumulation and bio concentration factors were in the order kidney ≈ gill > liver ≈ spleen in cadmium exposed group (groupII). In kidney, liver and gill the cadmium concentration increased as the duration time so that, after 30 days the level of cadmium in kidney, liver, gill and spleen was significantly (p≤0.05) higher than was in 15th day.