The concentrations of persistent organic pollutants (POPs) in the muscle or liver tissues of several deep-sea fish and the hadal snailfish (μg/kg wet weight). PCB7 (dark green bar chart) represents the sum of seven PCB congeners with a wide range of chlorination (28, 52, 101, 118, 138, 153, and 180), and PBDE7 (light green bar chart) represents the sum of seven PBDE congeners chosen for their frequent occurrence in the environment (28, 47, 99, 100, 153, 154, and 183). The vertical axis lists the names of the detected fish species and the selected tissue types. The red baseline represents the National Food Safety Standards of China (GB2762-2022) for PCBs in aquatic animal fats.
