Pesticide additive widespread in Canada groundwater

Another contaminant found in Canadian groundwater samples may join the list of environmental substances that could be harmful to humans and the environment, according to recent study results published in the September 2009 issue of Environmental Toxicology and Chemistry. The newest potential threat to human health and the environment is fluorochemicals known as perfluorinated phosphoric acids (PFPAs), which were found in water samples taken for study in the past decade from Canadian creeks, rivers and, waste treatment effluents. PFPAs were found at 24 of 30 sites used in the research, which is outlined in the article, “Perfluorinated Phosphonic Acids in Canadian Surface Waters and Wastewater Treatment Plant Effluent: Discovery of a New Class of Perfluorinated Acids,” by Jessica C. D’eon, Patrick W. Crozier, Vasile I. Furdui, Eric J. Reiner, E. Laurence Libelo, and Scott A. Mabury. PFPAs are used commercially as leveling and wetting agents and to defoam additives used in pesticide formulations. Similar fluorochemicals have been used for industrial purposes since the 1950s but were not identified as widespread environmental contaminants until 2001. As noted in the article, PFPAs lack hydrogen atoms and may resist degradation, like other fluorochemicals such as PFCAs and PFSAs—perfluorinated carboxylic and sulfonic acids—that once were used commercially and now are regulated in the United States and Canada. “From the analysis of Canadian surface waters, low-level PFPA contamination clearly is widespread,” according to the authors. PFPAs had not previously been identified as contaminants of potential concern (i.e., as possible pollutants), although the U.S. has acted to limit their use in food crop pesticides because of health concerns and a lack of research on their implications. …