Arsenic has been found in baby formula, cereal bars and other foods that use organic brown rice syrup as a sweetener, a finding that challenges assumptions.

People may seek foods labeled organic for health and environmental benefits. Now researchers in the U.S. say they've found higher levels of inorganic arsenic in commercial infant formula, cereal and energy bars sweetened with organic brown rice syrup than products without the syrup.

Arsenic is now considered toxic and potentially carcinogenic but it was used in medicine in the 19th and 20th centuries. (National Museum of American History, Behring Center, Smithsonian Institution)

Rice is among the plants that are efficient in taking up arsenic from the soil, environmental chemist Brian Jackson of Dartmouth College in Hanover, N.H., and his co-authors said in Thursday's issue of the journal Environmental Health Perspectives.

Long-term exposure to extremely high levels of inorganic arsenic can increase the risk of lung, liver and bladder cancer.

"There are currently no U.S. regulations applicable to arsenic in food," the study's authors concluded.

"Our findings suggest that the organic brown rice syrup products we evaluated may introduce significant concentrations of inorganic arsenic to an individual's diet. Thus, we conclude that there is an urgent need for regulatory limits on arsenic in food."

Health Canada also does not set limits on arsenic levels in food.

"I wouldn't say it is unsafe," CBC's medical specialist Dr. Karl Kabasele said of organic brown rice syrup.

Canada's limit for drinking water is 10 parts per billion, which leaves a safety margin before toxic effects are known to occur in humans, Kabasele said.

Regulatory limits

There is evidence that children exposed to extremely high levels of arsenic in groundwater in Bangladesh had their growth and IQ affected, according to the U.S. Environmental Protection Agency. That points to how consuming large amounts over a long period could be problematic, Kabasele said.

If parents are concerned, don't feed your baby only foods that are sweetened with rice syrup, he suggested, noting variety in diet should start early.

Health Canada said it conducts regular surveillance and the Canadian Food Inspection Agency monitors foods and beverages.

"If arsenic is detected at levels above those considered typical, Health Canada conducts a health-risk assessment to determine if the arsenic is present in a concentration that would be unsafe to human health. If a safety concern is identified, appropriate action is taken to ensure the health and safety of Canadians is protected," the department said in an email to CBC News.

Those actions include recalls, detaining products and establishing maximum limits.

With files from CBC's Melanie Glanz