Tissue distribution of perfluorinated compounds in farmed freshwater fish and human exposure by consumption

In the present study, the levels of 14 perfluorinated compounds (PFCs) were analyzed in the blood, liver, muscle, brain, and eggs of popular farmed freshwater fish from Beijing. Perfluorooctane sulfonate (PFOS) was the predominant compound in all samples, with the highest concentration at 70.7 ng/g wet weight. The highest mean levels of PFOS in all tissues were observed in bighead (1.48-22.5 ng/g wet wt) and the lowest in tilapia (0.260-1.63 ng/g wet wt). In addition, perfluoroundecanoic acid was the second dominant PFC in blood, liver, muscle, and eggs, with the highest concentration at 19.2 ng/g wet weight. However, perfluorodecanoic acid levels (less than the limit of detection LOD to 0.963 ng/g wet wt) were similar to or slightly higher than perfluoroundecanoic acid levels (<LOD to 0.918 ng/g wet wt) in the brain. Generally, the highest mean concentrations of PFOS and total PFCs were found in fish blood, followed by liver, brain, and muscle, further supporting the premise that PFOS can bind more easily to serum proteins than to fatty tissues. The egg to liver ratios as maternal transfer ratios were calculated for PFOS, ranging from 0.93 to 2.0. Furthermore, based on consumption information for fish in Beijing, the human dietary intake of PFCs through fish consumption were estimated at 0.24 ng/kg/d for PFOS and 0.44 ng/kg/d for total PFC. These results indicate a low health risk posed from PFCs to the residents of Beijing through the consumption of fish.