"Origin and Fate of Polyfluorinated Chemicals in the Environment" Dr. Scott Mabury (University of Toronto)

Perfluorinated acids (PFCAs and PFOS) are widely disseminated in the global environment and appear at high concentrations in humans and in Arctic mammals. We have developed the ‘precursor alcohol atmospheric reaction and transport’ or PAART theory to potentially explain these observations. Residual fluoro-alcohols are significant in fluorinated polymers and surfactants (food contact paper coatings) and may contribute significantly to the global burden, though we know little about the stability of the linkage chemistry within the fluorinated materials. Experiments have shown the ester and phosphate esters in monomers and surfactants are readily hydrolyzed through microbial and mammalian metabolism. The fluoroalcohols (e.g. FTOHs) are readily oxidized, via reactive intermediates, to the resulting PFCAs. Some of these intermediates have been shown to be highly toxic to D. Magna (ie 10:2 FTCA) or readily react with GSH (the acrylic aldehydes). These fluoroalcohols are also readily found in the atmosphere and have been shown to undergo atmospheric transport and OH driven transformation reactions to yield the observed perfluorinated acids. Model studies suggest significant production of these acids in remote Arctic regions have been confirmed by flux measurements into the ice cap. Temporal studies of biota contamination yield body burdens that appear to closely match production changes by industry. Human contamination is suggestive of an indirect source of exposure through metabolism of the fluorinated alcohols, which would indicate attention to the reactive intermediates is prudent. Evidence suggests many unrecognized organofluorines are present in the environment, some of which may be highly persistent, bioaccumulative, and environmentally problematic. This presentation will highlight the spectacularly interesting environmental chemistry of organofluorines and attempt to delineate the chemical architecture choices in maintaining the positive benefits while avoiding attendant pollution problems.

Dr. Mabury is the guest of Prof. Dajana Vuckovic