Just read this article and the following excerpts stood out to me.

And in 2011, working with the FDA, drug company Alpharma agreed to suspend the sale of Roxarsone, a poultry-feed additive, because it contained an organic form of arsenic that could convert into inorganic arsenic inside the bird, potentially contaminating the meat. Or it could contaminate soil when chicken droppings are used as fertilizer. Other arsenic feed additives are still being used.
Over the years, a shift has occurred in how juice sold in America is produced. To make apple juice, manufacturers often blend water with apple-juice concentrate from multiple sources. For the past decade, most concentrate has come from China. Concerns have been raised about the possible continuing use of arsenical pesticides there, and several Chinese provinces that are primary apple-growing regions are known to have high arsenic concentrations in groundwater.
Robert Wright, M.D., M.P.H., associate professor of pediatrics and environmental health at Harvard University who specializes in research on the effect of heavy-metals exposure in children, says that findings from our juice tests and database analysis concern him: “Because of their small size, a child drinking a box of juice would consume a larger per-body-weight dose of arsenic than an adult drinking the exact same box of juice. Those brands with elevated arsenic should investigate the source and eliminate it.”