Global occurrence, bioaccumulation factors and toxic effects of polychlorinated biphenyls in tuna: A review
Polychlorinated biphenyls (PCBs) tend to accumulate in adipose tissue and induce toxicity due to their high lipophilicity and persistence. Tuna play an important role in the ocean food web and human diet. PCBs can damage the growth of tuna directly and have some adverse effects on human indirectly. This review aims to provide geographic variations, bioaccumulation factors and the toxic effects of PCBs in tuna. PCB levels found were varied significantly among the different regions and it showed a trend of offshore greater than pelagic, with the northern hemisphere higher than the southern hemisphere. The highest PCB concentration of tuna was in FAO area 37. Nearly all of the specimens presented similar domain configuration, while their concentrations varied significantly. PCB congeners and concentrations in tuna were affected by a vast of factors, such as geographical distribution, tissue types, trophic level and growth stage, gender, tuna species and physical and chemical properties of PCBs. They can damage reproductive, neurologic and development systems. This review gives a systematic insight into PCBs in tuna and highlights the more attention should be paid to the long-term changes of PCBs in tuna and oceans. There is also a need to strengthen the assessment of PCB impacts on tuna ecology.