Cadmium contamination of drinking water and its treatment using biological chelators

Abstract

Background: Cadmium (Cd) is an extremely toxic metal and environmental exposure to Cd has been particularly problematic in the world. Oral exposure to Cd may result in adverse effects on a number of tissues, the immune system, and the cardiovascular system. Compounds containing Cd are also carcinogenic. The presence of Cd in drinking water resources in the southeastern region of Rafsanjan plain (Iran) at concentrations greater than acceptable limits may result in various adverse health effects. The aim of this research was to test the chelation potency of deferasirox (DFS or ICL670), a tridentate metal chelator, and deferiprone (L1), a bidentate metal chelator, in the mobilization of Cd in Cd-exposed rats as a biological model. Materials and Methods: Male Wistar rats were exposed to 40 mg/kg body weight of cadmium chloride in drinking water for 6 weeks, followed by treatment with DFS (100 mg/kg body weight, oral, once daily) and L1 (100 mg/kg body weight, oral, once daily), alone or in combination, for 7 consecutive days. After chelation therapy, the rats were anesthetized by ether vapor and immobilized by cervical dislocation. Then, their heart, liver, kidneys, intestine, and blood were sampled for clinical hematological variables and determination of Cd and Fe concentration by inductively coupled plasma optical emission spectrometry (ICP-OES). The data were subjected to statistical analysis using Student’s t-test. All Ρ values of less than 0.05 were considered significant. Results: The results show that both chelators (DFS and L1) increase the removal of Cd from the tissues. No effects of Cd or any of the two treatments (L1 or DFS) were observed on white blood cell (WBC) count, red blood cell (RBC) count, and hemoglobin‎ (Hb) level. Conclusions: The comparison of single and combined therapy showed that the combined chelation therapy (DFS + L1) was more effective in depleting Cd concentration in soft tissues.