University of Toronto scientists have published a study suggesting that a significant source of perfluorinated carboxylic acids (PFCAs) in human sera are the polyfluoroalkyl phosphate esters (PAPs) used in food-contact paper packaging, particularly popcorn bags and fast food wrappers. Jessica D’eon & Scott Mabury,“Exploring Indirect Sources of Human Exposure to Perfluoroalkyl Carboxylates (PFCAs): Evaluating Uptake, Elimination and Biotransformation of Polyfluoroalkyl Phosphate Esters (PAPs) in the Rat,” Environmental Health Perspectives, November 8, 2010. PAPs are used to prevent water and fat from escaping the packaging. According to lead researcher Scott Mabury, “Those chemicals called PAPs move into food, make it into humans upon ingestion and metabolically are transformed into the PFCAs.”

While it is apparently unknown whether these chemicals have an adverse effect on human health, Mabury said PFCAs are “highly reactive” and, hence, of concern. The authors note that PFCAs have been found in human sera worldwide, but major sources are not well understood. Some scientists speculated that environmental contamination from past chemical use was to blame for its persistence, and this study was designed to determine whether continuing PFCA exposure was the source. The researchers synthesized PAP, exposed lab rats to various concentrations of the chemical and report that “PFCA biotransformation products were observed in the blood of the diPAPdosed animals.” See Brandon Sun, November 10, 2010.