This thesis studied the cytotoxicity of mercuric chloride on human epihelial cells. The three detection techniques were developed to monitor the cytotoxicity of soluble mercuric chloride to human health. Both increased concentration and exposure time resulted in increased DNA damage and cell death. At lower levels death occurred by a mixture of apoptosis and necrosis, while at higher levels cell death occurred primarily by necrosis. This is the first study to demonstrate a deleterious effect of soluble mercuric chloride on human epithelial cells, although mercury has long been known as nephrotoxic and neurotoxic.