""Chemicals Lurking in Microwave Popcorn BagsHarmful chemicals found in many types of food packaging leeching into foods11/08/2010 | ConsumerAffairs

By Sara Huffman

Junk food addicts may want to consider kicking the habit; if not to avoid eating so many calories, but to avoid eating so many chemicals.

University of Toronto scientists have found that chemicals used to line junk food wrappers and microwave popcorn bags break down and become perfluorinated carboxylic acids or PFCAs which leech into foods when ingested, contaminate the blood.

These chemicals can be found in anything from non-stick kitchen pans to clothing to food packaging.

PFCAs, the best known of which is perfluorooctanoic acid (PFOA), are found in humans all around the world.

"We suspected that a major source of human PFCA exposure may be the consumption and metabolism of polyfluoroalkyl phosphate esters or PAPs," says Jessica D'eon, a graduate student in the University of Toronto's Department of Chemistry.

"PAPs are applied as greaseproofing agents to paper food contact packaging such as fast food wrappers and microwave popcorn bags."

In the U of T study, rats were exposed to PAPs either orally or by injection and monitored for a three-week period to track the concentrations of the PAPs and PFCA metabolites, including PFOA, in their blood. Human exposure to PAPs had already been established by the scientists in a previous study.  

Researchers used the PAP concentrations previously observed in human blood together with the PAP and PFCA concentrations observed in the rats to calculate human PFOA exposure from PAP metabolism. 

Major source of exposure

"We found the concentrations of PFOA from PAP metabolism to be significant and concluded that the metabolism of PAPs could be a major source of human exposure to PFOA, as well as other PFCAs," said Scott Mabury, the lead researcher and a professor in the Department of Chemistry at the University of Toronto.

"This discovery is important because we would like to control human chemical exposure, but this is only possible if we understand the source of this exposure.  In addition, some try to locate the blame for human exposure on environmental contamination that resulted from past chemical use rather than the chemicals that are currently in production," said Mabury.

While the effects of PFCA exposure is currently unknown, there is growing evidence that other chemicals used in food packaging leech into foods and cause harm to people when ingested.

Bisphenol-A, or BPA, a chemical the linings of cans used for food and beverages, has already been linked to low sperm count in men andaggressiveness in girls.

Perhaps because of this, regulatory interest in human exposure to PAPs has been growing.  

Governments in Canada, the United States and Europe have signaled their intentions to begin extensive and longer-term monitoring programs for these chemicals.  The results of this investigation provide valuable additional information to such regulatory bodies to inform policy regarding the use of PAPs in food contact applications.

The study was conducted by Jessica D'eon and Scott Mabury of the University of Toronto's Department of Chemistry and is published today in Environmental 
Health Perspectives.  Research was funded by the Natural Sciences and Engineering Research Council of Canada."




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