Evaluation of the effect of lead exposure and chelation therapy on the factors affecting the toxicity

Lead (Pb) is a heavy metal with substantial toxic properties which is broadly used across industries in Turkey and around the world. Sodium calcium EDTA is an important chelation agent used in the treatment. In this dissertation study, we assessed effects of the chelation therapy used on certain Pb toxicity-indicating parameters and on essential element levels. Blood and urine samples were collected from 42 workers with Pb exposure before and after chelation therapy, and the essential element levels, oxidative stress parameters (malondialdehyde (MDA), protein carbonyl (CO), 9-hydroxy-deoxy-guanosine (8-OHdG)) levels, activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)), glutathione (GSH) levels, ALAD enzyme activity and polymorphism were evaluated. Also, caspase-8 levels were measured to assess the modification of apoptosis –possibly induced by Pb– by chelation therapy. The chelation therapy used resulted in significant reduction of calcium, copper, manganese and selenium levels in workers exposed to Pb. Also, the oxidative stress parameters and caspase 8 levels that were elevated after chelation therapy generally receded, but we observed increased antioxidant enzyme activity and a significant elevation of ALAD levels. In the aforementioned study group, ALAD1-1 in 36 workers, ALAD1-2 in 5 workers, and ALAD2-2 isozymes in 1 worker were found. In conclusion, chelation therapy was effective in reversing apoptosis and oxidative damage caused by Pb exposure. We consider that supplements can be used to address the reduction in essential element levels.