TRIFLUOROACETATE, AN ATMOSPHERIC BREAKDOWN PRODUCT OF HYDROFLUOROCARBON REFRIGERANTS - BIOMOLECULAR FATE IN AQUATIC ORGANISMS

Aquatic organisms were monitored for their ability to incorporate trif luoroacetate (TFA), an atmospheric breakdown product of HFC and HCFC r efrigerants containing a trifluoromethyl moiety. Because of the struct ural similarity of TFA to acetate, a biochemical intermediate and micr obial nutrient, we suspected that organisms might use the fluorinated compound to synthesize biomolecules such as lipids and acetylated prot eins. We exposed aquatic organisms (microbial communities, oligochaete s, macroinvertebrates, Callitriche sp., Lemna sp., and Impatiens capen sis) to radioactive TFA ([C-14]F3COOH) and examined them for distribut ion of radiolabel in different classes of biomolecules. The most label was found in oligochaetes and I. capensis leaves at 3 and 6 mu g/g (a s TFA), respectively, with the greatest proportion found in the protei n fraction for each sample type. Aerobic microorganisms incorporated o nly a small fraction of the label (a few nanograms per gram as TFA), a nd the greatest proportion of label occurred in cell wall material. We have demonstrated that selected aquatic organisms spanning a range of trophic levels incorporated the xenobiotic TFA into their biomolecule fractions so that it was no longer extracted as TFA and thus was meta bolically transformed.