HANOVER, N.H. — High levels of arsenic were found in infant formulas and cereal bars that contain organic brown rice syrup as a main ingredient, according to a new study from Dartmouth College researchers. The arsenic found in the food products has been identified as a human carcinogen, and some studies have shown it may cause skin, lung and intestinal irritation. The research paper, published on-line Feb. 16 in the journal Environmental Health Perspectives, found that among 29 cereal bars tested, those containing syrup or other forms of rice had arsenic levels 2 to 12 times higher than the allowable limit. There currently are no U.S. regulations for arsenic in food, but the researchers said there is “an urgent need” for regulatory limits. Legislation was introduced in Congress earlier this month to establish limits for arsenic and lead in fruit juice.