The impact of climate change on air-water exchange of toxaphene in Lake Superior

Abstract

This study examined how toxaphene dynamics in Lake Superior have changed since 1995. A model developed by Swackhamer et al. (1999) was updated using measurements taken by the National Data Buoy Center to represent conditions from 1995 to 2012. Buoy trends observed on Lake Superior from 1979-2012 were projected out to 2035 to predict conditions resulting from climate change. The model was compared to sampling measurements taken in Lake Superior during the summer of 2006 and was within the 95% confidence interval of vapor-phase and dissolved-phase toxaphene concentrations. Moreover, the model predicts that climate change will decrease concentrations of toxaphene in the lake faster than if conditions remained the same, however the effect is small. In 2035, the dissolved concentration is predicted to be 20.6% less when the model includes climate change. With climate change, volatilization dominates year-round across the air-water interface, making Lake Superior an indirect source of toxaphene to the atmosphere.