Investigation of effects of trifluoroacetate on vernal pool ecosystems

Trifluoroacetate (CH3COO-, TFA) is a breakdown product of hydrochlorofluorocarbons and hydrofluorocarbons and is released by the heating of Teflon products. Because of its chemical properties, concentrations in evaporative wetlands are predicted to increase with time. This study focused on assessing the impact of this haloacetic acid on vernal pool soil microbial communities as well as vernal pool and wetland plant species. Microbial respiration for three vernal pool soils and an agricultural soil was not affected by TFA exposures (0, 10, 100, 1,000, and 10,000 microg/L), and degradation of TFA by microbial communities was not observed in soils incubated for three months. Trifluoroacetate accumulated in foliar tissue of wetland plant species as a function of root exposure concentration (100 and 1,000 microg/L TFA), and accumulation was found to stabilize or decrease after the second or third month of exposure. Seeds accumulated TFA as a function of root exposure concentration; however, germination success was not affected. No adverse physiological responses, including general plant health and photosynthetic and conductance rates, were observed for root exposures at the TFA concentrations used in this study. Based on the soils and plant species used in this study, predicted TFA concentrations will not adversely affect the development of soil microbial communities and vernal pool plant species.