Background: Inorganic arsenic which contaminates drinking water of more than 100 million people worldwide is a carcinogen and long-term exposure to arsenic can pose one of greatest threats to our health. Even low levels of arsenic exposure increase the bladder, skin and lung cancer risk. It may contribute to up to 5297 lung cancer cases per year and approximately a two-fold increase in the Squamous Cell Carcinoma risk.

Materials and Methods: Recent studies have reviewed using PubMed, Google scholar, science direct, Avid and NCBI databases.

Results: Arsenic can affect cancer initiation and development through the induction of oxidative stress and production of ROS. Methylation of arsenic by S-adenosyl methionine and glutathione results in highly toxic methylated Arsenic species with potent enzyme inhibitory and cytotoxic activity. Also it can cause epigenic mechanisms like histone modification, and alternation of DNA methylation. Arsenic can bind to sulfhydryl groups of cysteine in some proteins and inhibit their activity. Moreover, it has synergistic effects with tobacco and alcohol in cancer induction.

Conclusion: According to the results of this study, Arsenic exposure can be considered as a potent biomarker for Arsenic-induced carcinogenicity. Explanation of the carcinogenic mechanisms of Arsenic is important to prevent and treatment of Arsenic-induced cancers.