Arsenic is a heavy metal, typically used in pesticides, rodenticides, weed killers, paint, and wood preservatives. It is a contaminant in food and water sources. Shellfish and other seafood, as well as fruits, vegetables, and rice; are the foods most commonly contaminated. Arsenic poisoning typically occurs as a result of industrial exposure, from contaminated wine, or illegally distilled spirits. Fasting is not required for this test. Take all medications as prescribed.