Figure 2: This figure shows the concentrations of dioxins and furans in nanograms toxic equivalency factors Toxic Equivalencies per kilogram dry weight in sediment samples in Lake Superior, Lake Huron, Lake Ontario and Lake Erie from  2004 to 2012. Elevated concentrations of greater than 107.5 Toxic Equivalencies per kilogram dry weight are indicated by red circles in Lake Huron and Lake Ontario. 