Arsenic is a naturally occurring element and can be found in food, water, or air. There are also industrial sources of arsenic, including mining and smelting.[6] "People are exposed to elevated levels of inorganic arsenic through drinking contaminated water, using contaminated water in food preparation and irrigation of food crops, industrial processes, eating contaminated food and smoking tobacco. Long-term exposure to inorganic arsenic... can lead to chronic arsenic poisoning.