Evaluation of the Cytotoxic Effects of Heavy Metals in Laboratory Animals

Abstract

Scientific evidence indicates that exposure to heavy metals commonly present in consumer products, water, and air can lead to significant cytotoxic and genotoxic effects. This study evaluated the combined effects of zinc (Zn) and cadmium (Cd) exposure on the genetic makeup of white laboratory mice (C57BL). A total of 150 mice were divided into three equal groups: the first received drinking water containing cadmium salts (0.685 mg/L), the second received zinc salts (0.567 mg/L), and the third served as a control. After a 90-day exposure period, cytotoxic and genotoxic effects were assessed using the comet assay, mitotic index (MI), blast index (BI), and micronucleus (MN) test in lymphocytes. Chronic cadmium exposure significantly increased the mitotic index (37.67 ± 4.95) and micronucleus frequency (1.42 ± 0.26) (P < 0.01), with the highest values observed in the third month, whereas no significant differences were found between the zinc-treated and control groups. These findings confirm the genotoxic potential of cadmium and highlight the importance of continuous monitoring of environmental exposure to heavy metals to protect the health and genetic integrity of living organisms.