Cestodes are Bioremediation Tools by Absorbing the Heavy Metals from Their Hosts

Abstract

The helminthes may act as indicators of pollution of the environment where their hosts live. The present study was conducted to evaluate the role of cestodes in the elimination of some toxic minerals such as cadimum (Cd) and chrome (Cr) in wild rats (Rattus norvegicus) which has been used as a model. The results showed that there are high concentrations of Cd and Cr in kidneys and livers compared to intestines and muscles of captured rats from industrial and agricultural areas in Diyala Province. The concentrations of both Cd and Cr were significantly higher (P< 0.05) in the cestodes than in the rat tissues. The bioaccumulation factor for Cd increased 3.2 folds and 2.1 folds in the worms than in the intestines and muscles of the rats, respectively in agricultural areas and 2.8 folds and 1.4 fold in worms than in the intestines and muscles of rats captured the in industrial areas. For Cr, the bioaccumulation factor increased 3.1 folds and 2.8 folds in worms than in the intestines and muscles of rats from the agricultural areas while it increased 2.7 folds and 1.4 fold in worms than in the intestines and muscles in the industrial areas. In conclusion, and in comparison, between infected and non-infected rats and the bioaccumulation factors in the present study, it is possible to propose the ability of the cestode (Hymenolepis diminuta) to absorb some toxic elements such as Cd and Cr from their hosts.