PCB concentrations in Otters 2010-2019

Data are concentrations of 23 different PCB (polychlorinated biphenyl) congeners, measured in otter liver tissue taken from otters found dead in Wales between 2010 and 2019. Otters found dead were collected as part of the Cardiff University Otter Project https://www.cardiff.ac.uk/otter-project. One hundred liver samples were selected for analysis from the CUOP archive from otters which had died between 2010 and 2019, in Wales. The concentrations of 23 PCB congeners were quantified in the otter liver samples using GC-MS, concentrations were reported in µg/kg wet weight (ww).

Column headings: Otter ID is a numeric identifier of the otter from which samples were taken. % Lipid and % Dry Wt quantify the liver tissue lipid content and dry weight percentage, respectively. SumTEQ is the sum of the toxic equivalency factors (TEFs) from six dioxin-like PCB congeners (PCB 77, 105, 118, 126, 156 and 169). Exceed TEQ is a binary variable describing whether the calculated SumTEQ value exceeded a threshold value suggested to be of toxicological significance. SumPCBAll23 is the total concentration of PCBs, summed across the 23 congeners measured. SumPCB9 is the total concentration of PCBs, summed across 9 congeners (PCBs 105, 118, 128, 153, 156, 157, 167, 170 and 180), all of which measured above limit of detection in >70% individuals. PCB 8, 20, (etc) to 189 are the concentrations (measured in ug/kg wet weight) for each of the listed PCB congeners. Values less than LOQ (limit of quantification) were assigned 0.5 × LOQ; congeners marked with an asterisk are those where concentrations were measured with less precision.