PCDDs (dioxins) and PCDFs (furans) in selected UK lake and reservoir sites — concentrations and TEQs in sediment and fish samples

This paper describes a study that was designed to increase present knowledge of the levels and behaviour of atmospherically derived View the MathML source in UK freshwaters. Sediment and fish samples were taken from four freshwater locations where the main sources of View the MathML source were thought to be atmospheric. Total concentrations in sediments ranged from 500–5000 ng kg−1 dry weight, and toxic equivalents (I-TEQs) between 5–100 ng kg−1 dry weight. Sedimentary evidence was used to derive total inputs of View the MathML source to the lakes and from this it seems probable that two of the sample sites receive inputs of View the MathML source largely from the atmosphere, and that the remaining two sites receive additional inputs from local or regional sources. View the MathML source were present in all fish samples taken, with total concentrations between 100–800 ng kg−1 wet weight and TEQs between 1–20 ng kg−1 wet weight. These values were consistent with those found in other international studies. Whilst results provide some evidence for within-site similarities between different fish types, they did not suggest any similarities between the same species at different sites. There was no evidence for a relationship between total View the MathML source concentrations in sediment and fish, although a relationship between 2378-substituted isomer levels in some sediment and fish samples was noted.