Safety evaluation of a traditional knowledge based copper device for microbial purification of drinking water at home

Copper as a trace element plays an important role in several physiological functions. Earlier studies have reported an affordable copper based device causing microbial decontamination of drinking water by leaching of similar to 120 ppb of copper, when left in contact with water for 16 hrs. This study tested the oral toxicity of copper device treated water over a period of 90 days in Sprague Dawley rats following the OECD (Organisation for Economic Co-operation and Development) test guideline 408. Two groups of animals were used (12 rats in each test and control group) wherein the control group animals were fed with rodent diet with normal drinking water and test group animals fed with the same diet but supplemented with water containing 100-120 ppb of copper. After 90 days of exposure, clinical chemistry, histopathology, tissue enzymes of liver and kidney and serum copper levels were studied. There was no significant difference observed in the clinical chemistry of serum samples (p > 0.05) and histopathology of various organs examined. A gender-related difference in the serum copper levels in female rats was found to be statistically significant, p < 0.05. Overall, copper in drinking water at levels of 100-120 ppb was found to be non toxic in SD rats in this study.