This page presents an explanation of the issues, links to the reference sources and a bottom line conclusion.
A known carcinogen, inorganic arsenic also has been associated with skin lesions, developmental effects, cardiovascular disease, neurotoxicity, and diabetes. Chronic arsenic exposure can initially cause gastrointestinal problems and skin discoloration or lesions. Signs of chronic low-level arsenic exposure can be mistaken for other ailments such as chronic fatigue syndrome.
Inorganic arsenic, the sum of arsenite (As+3) and arsenate (As+5), is generally considered more toxic than organic arsenic, and some organic species in food (such as arsenobetaine, commonly found in seafood) are considered nontoxic (
Arsenic is a naturally occurring substance and naturally finds its way into many foods, from apple juice and rice to meats like chicken, but usually in trace amounts.
Older pesticides (now banned) contained arsenic, which led to a build-up of arsenic in soils, which can still find its way into foods. Arsenic was also used in a preservative for pressure-treateing wood (that was baned in 2003) , which is commonly used for decks and playground equipment. Consumer Reports has an interactive map of the known contamination of groundwater here.
Imported foods, from countries with no or lax standards or poor enforcement, like China (from which much apple juice is imported to the U.S.) also accounts for the presence of some arsenic in our food. See this story "Why Americans Should Worry About China's Food Safety Problems " in the - Wall Street Journal, May 21, 2013.
Many of the references are found by links throughout the article above, but are present ehere for clarity: