A test of popular processed foods from some of the biggest names in the industry found trace amounts of mercury, according to the Institute for Agriculture and Trade Policy, a nonprofit group based in Minneapolis. The amounts of mercury found was far less than that commonly seen in most fish and seafood, but turned up in many foods not previously known to be sources of mercury, including many preferred by children, the group said. It includes Nutri-Grain Strawberry Cereal Bars, Quaker Oatmeal to go bars, Hershey's Chocolate Syrup, Yoplait Strawberry yogurt, Market Pantry Grape Jelly and Coca-Cola, it said. "This seems like an avoidable source of mercury that we didn't know was out there," said David Wallinga, one of the study's co-authors. The study concluded that the mercury came from food plants that use caustic soda laced with mercury to produce high fructose corn syrup for major food companies. The researchers cautioned that their study was limited. It tested 55 consumer items, finding mercury in one third of the samples ranging from 30 to 350 parts per trillion. A part per trillion is the rough equivalent of a drop of water in 20 Olympic-sized swimming pools. Several companies named in the IATP report defended their products Monday, pointing to the very low levels of mercury detected. "You would have to eat more than 100 pounds of ketchup each day to even come close to reaching the EPA's safe exposure level," said ConAgra spokeswoman Stephanie Childs. A spokesman for General Mills challenged the science behind the report, saying it didn't identify which form of mercury was detected and that parts per trillion of mercury can be found in water, soil and plant and animal tissue. "To suggest a safety concern on the basis of this study is irresponsible," said Tom Forsythe, a spokesman.

A group representing the high fructose corn syrup industry said food plants no longer use the mercury-containing ingredients that caused contamination in the past, adding that four-year-old samples were cited in an academic paper that was released in tandem with the IATP report. "This study appears to be based on outdated information of dubious significance," said Audrae Erickson, president of the Corn Refiners Association. The IATP, however, said four plants in Georgia, Tennessee, Ohio and West Virginia still use the "mercury-cell" technology that leads to contamination. A fifth plant in Wisconsin has begun converting its plant to use mercury-free agents. The report was published Monday in the peer-reviewed journal Environmental Health. Lead author Renee Dufault, a former Food and Drug Administration scientist, said she presented findings about mercury in processed food to the FDA after preliminary testing in 2005. "Environmental mercury exposure via food, water and air is a threat to sensitive populations -- those who may not be able to effectively metabolize mercury (autistic children and the elderly). Sensitive populations may be bioaccumulating mercury and this leads to neurological effects," she said in an email. An FDA spokesman said the agency was overwhelmed with the peanut butter salmonella scare and could not respond immediately to this issue. The mercury findings, while potentially alarming, should be viewed in context, said Michael Jacobson, executive director of the Center for Science in the Public Interest. The report found 300 parts per trillion of mercury in Jack Daniel's Barbecue Sauce, but that's still 30 to 3,000 times less than the amount of mercury found in fish and seafood. "I suspect people eat more fish than barbecue sauce," he said. The type of mercury commonly found in fish and seafood is methyl mercury, and its effects are known to be toxic, but the type of mercury found in the packaged foods is not yet known, the report's authors said.

Heavy metal contamination in the food chain of industrialized nations is not uncommon. A 2004 study by the World Health Organization found an average adult consumes 100 micrograms of mercury per week in Portugal, and more than 50 micrograms per week in Italy, Germany and France. Here are the responses about the report from some of the major food companies: General Mills: "We have serious doubts about the scientific merit of this report. The main premise -- that the processing of high-fructose corn syrup is responsible for traces of mercury in products - is not established by this study. Levels of elemental mercury at parts per trillion or greater can be found throughout the environment in water, in soil and in plant and animal tissues. This study does not establish that any mercury detected comes from HFCS -- and there is no evidence that suggest it is in the organic form of mercury (that which has demonstrated health impact). To suggest a safety concern on the basis of this study is irresponsible. Questions about the analytical methodology used in the study remain unanswered as well. If this study is to be reported upon, it may be just as important for consumers to know that - even if present at the levels reported -- the levels supposedly cited in this paper would be minimal, and well below any concern level set by either U.S. or international regulatory bodies. Of all of the many facts that this paper fails to mention, that may be the most important point for readers to know." Hershey's: Hershey products are safe to consume, and all ingredients meet our stringent quality and safety guidelines, as well as applicable federal requirements, said Kirk Saville, a spokesman for Hersheys. Kellogg: Was the company aware of this type of mercury contamination? The food industry tests at the parts per billion level. This study looked at parts per trillion, a level that is 1,000 times lower than the already stringent threshold of parts per billion.