Arsenic is a chemical element that occurs naturally and is toxic to humans. Chronic arsenic poisoning results from long-term exposure, mainly through drinking contaminated groundwater, which affects over 100 million people worldwide. The worst affected area is Bangladesh, where over 77 million people have been exposed to toxic levels of arsenic in groundwater. Long-term arsenic exposure is linked to cancers and skin lesions, as well as other health issues. The main symptoms of arsenic poisoning include headaches, diarrhea, and skin pigmentation changes.