Pathophysiology of arsenic-induced adverse health effects

Chronic exposure to arsenic is associated with cancers of lung, urinary bladder, kidney, liver and skin, as well as vascular diseases, infections, and neurological abnormalities. Arsenic has been declared as a class I carcinogen by the International Agency for Research on Cancer (IARC). Skin cancers are the most common arsenical cancers and usually herald the development of other internal cancers. Although the exact mechanisms of actions of arsenic inside the cells remain to be clarified, the histological changes in arsenical skin cancers and mechanistic studies suggest that aberrant differentiation, proliferation, abnormal apoptosis, dysregulated immune responses, and abnormal mitochondrial homeostasis contribute to the arsenic carcinogenesis. After a brief introduction to arsenic, this review summarises the potential mechanisms involved in the arsenic-induced adverse health effects. Such information may provide further clues to tackling the molecular mechanisms for arsenic carcinogenesis and other adverse health effects.