Infant formula and other foods sold in the United States contain worrisome levels of arsenic, according to a new study.  Arsenic is toxic heavy metal that when ingested can cause hair loss, convulsions, organ failure and cancer.

Most arsenic came from organic brown rice syrup, a sweetener used in foods ranging from infant formulas, cereal bars and energy shots used by endurance athletes.

Though the federal government does not regulate arsenic in food, researchers from Dartmouth College found arsenic levels in some foods far exceeded the limits for arsenic in drinking water accepted by the U.S. Environmental Protection Agency.

The study included 17 infant formulas, two of which contain organic brown rice syrup as the primary ingredient. High arsenic levels were found in both; one had six times the federal limit for arsenic in drinking water. The findings are particularly worrisome since infants are more vulnerable to arsenic due to their low body weight, the authors said.

The researchers did not specify which brands they tested. Infant formula producer Nature's One uses organic brown rice syrup and issued a statement saying company officials are aware of the study.

As an organic manufacturer, Nature's One's primary concern is the amount of environmental chemicals ingested by infants, toddlers and children, the statement read. Parents can rest assured that Nature's One will test arsenic levels for every lot of organic brown rice syrup.

Twenty two out of 29 cereal bars tested contained organic brown rice syrup or other rice products as one of the top five ingredients. The bars containing rice products had between 100 and 1,000 percent more arsenic than the EPA-recommended limits.

Energy shots could be one of the more dangerous products because of heavy consumption by athletes, the researchers found.

The manufacturer recommends consuming up to two servings [of energy shots] per hour during exercise, so an endurance athlete consuming four servings during a two-hour workout would consume [arsenic levels equal to the] consumption of one liter of water at the current EPA limits, the researchers wrote. The journal Environmental Health Perspectives published the study on Thursday.

The take home message is that parents need to pay attention to the ingredients in their baby's food, according to Brian Jackson, lead author of the study and environmental chemist at Dartmouth College.

In the absence of regulations for levels of arsenic in food, I would certainly advise parents who are concerned about their children's exposure to arsenic not to feed them formula where brown rice syrup is the main ingredient, Jackson said in a statement.

Rice grown in the United States is a common source of arsenic. Fields where rice is grown were often previously used to grow cotton, where arsenic was used as a pesticide to kill boll weevils, a crop destroying insect according to a study published in Nature in 2005.

This study is the second this year to show dangerous levels of arsenic in everyday foods.

In January, Consumer Union, a consumer advocacy group, issued a report that showed high levels of arsenic in apple and grape juice. The group tested 31 juices and found five apple and four grape juices that contained levels of arsenic higher than the EPA limits.

The current analysis suggests that these juices may be an important contributor to dietary arsenic exposure, Keeve Nachman, a scientist at the Center for a Livable Future and the Bloomberg School of Public Health who helped test the juices, told Consumer Reports. It would be prudent to pursue measures to understand and limit young children's exposures to arsenic in juice.

The Food and Drug Administration was not available for comment.