ABSTRACT
Recently, studies have been attempted to evaluate the risks associated with a lifetime exposure to chlorinated drinking water, where it has been reported to impair some immune functions. The present study amis to investigate the safety limits and the potential toxic effects of different concentrations of chlorinated drinking water on the cell mediated immunity. In this study, 56 adult male albino rats were used. Animals were divided into seven equal groups [n= 8], one control and three group were treated with sodium hypochlorite at different concentrations 2, 15, 30 parts per million, and the remaining three groups were also treated with monochloramine at concentrations 2, 15, 30 parts per million respectively. The study Lasted for three months. For each animal, body weight, spleen weight per body weight ratio, phagocytic function of peritoneal macrophages, electron microscopic study of splenic macrophages, lymphocyte blastogenesis and interleukin-2 were investigated for evaluation of immune activity at the different concentrations of both agents. Results showed that the whole body weight was not significantly affected. While the spleen weight/body weight ratio was significantly decreased. Also, phagocytic function of peritoneal macrophages, lymphocyte blastogenesis and interleukin-2 were significantly decreased. Electron microscopic examination of the splenic macrophages showed high activation at the lowest concentration 2 parts per million, while higher concentrations 15 and 30 parts per million showed different degrees of suppression, reaching it's maximal effect at the highest concentration [30 parts per million]. These changes could be attributed to the toxic effects of the chlorine byproducts on the immune system