The concentrations of four potentially toxic elements were analyzed in 70 spraint samples of Eurasian otters from the Daechung Lake area. The median concentrations of As, Hg, Ni, and Pb were 1.19, 1.06, 9.95, and 0.37 μg/g dry weight, respectively. A moderate negative correlation was observed between the levels of Hg and Pb (rs = -0.47). The Hg levels showed a weak negative correlation with the distances of the sampling locations from the Daechung Dam (rs = -0.35). This study provides baseline information on the health risks associated with the hazardous elements in otter species.

Arsenic is an environmental pollutant and is known to induce toxicity. Arsenic acts on cells through a variety of mechanisms, influencing numerous signal transduction pathways. It induces a variety of cellular effects such as apoptosis, growth inhibition, promotion or inhibition of differentiation and angiogenesis. Arsenic has been associated with cancers of the skin, bladder, lung, kidney, and liver as well as with noncancerous conditions, diabetes and hepatopathy. However, arsenic trioxide (ATO) was reported to induce remission in patients with acute promyelocytic leukemia (APL). The anticancer efficiency of ATO was not restricted to APL; however, it has been extended to many solid tumors, including liver, cervical, prostate, lung, esophagus, and bladder tumors. Therefore, in this study, a number of previous studies are summarized that demonstrate arsenic-induced toxicity, including carcinogenesis and anticancer activity in vitro and in vivo. The arsenic metabolism that is involved in arsenic-induced toxicity is also discussed.