Thank you for sharing this, Nunik! It seems the post you link is right to caution that lumping the low mercury and PCB claim together for small pelagics as is often done (even in our own post—prior to the update we just made!) is misguided. I tried to do further research and it seems to me the following is true (I’m new to the topic, so please say if you know otherwise):
PCB concentrations are extremely geographically and temporally variable. Areas like the Baltic sea or SF Bay are very high in PCBs, but levels in the open oceans are much lower. Also, PCBs have been banned from the 80′s and levels in fish have been declining as more of the PCBs sediment to ocean floors, so it is becoming less of a concern.
PCBs are hydrophobic, thus they do accumulate in fishes, particularly their fat. As sardines/anchovies are fatty, they contain higher PCBs than less fatty fishes like Cod.
PCBs like most contaminants biomagnify. Predators consuming sardines will absorb the PCBs in their fat, increasing their PCB levels. Thus, sardines/anchovies may be less contaminated than equally fatty but longer-lived/higher trophic level fishes.
It really does seem PCB levels can be a health concern, something I was not as aware of before. However, health authorities still lean heavily towards promoting the consumption of oily fishes, often even singling out sardines/anchovies as top choices. I suppose the trade-off of higher PCBs but higher EPA/DHA + other nutrients is still a positive one, but I would love to explore this deeper! Let me know if you have any insights on this topic :)
Thank you for sharing this, Nunik!
It seems the post you link is right to caution that lumping the low mercury and PCB claim together for small pelagics as is often done (even in our own post—prior to the update we just made!) is misguided.
I tried to do further research and it seems to me the following is true (I’m new to the topic, so please say if you know otherwise):
PCB concentrations are extremely geographically and temporally variable. Areas like the Baltic sea or SF Bay are very high in PCBs, but levels in the open oceans are much lower. Also, PCBs have been banned from the 80′s and levels in fish have been declining as more of the PCBs sediment to ocean floors, so it is becoming less of a concern.
PCBs are hydrophobic, thus they do accumulate in fishes, particularly their fat. As sardines/anchovies are fatty, they contain higher PCBs than less fatty fishes like Cod.
PCBs like most contaminants biomagnify. Predators consuming sardines will absorb the PCBs in their fat, increasing their PCB levels. Thus, sardines/anchovies may be less contaminated than equally fatty but longer-lived/higher trophic level fishes.
It really does seem PCB levels can be a health concern, something I was not as aware of before. However, health authorities still lean heavily towards promoting the consumption of oily fishes, often even singling out sardines/anchovies as top choices. I suppose the trade-off of higher PCBs but higher EPA/DHA + other nutrients is still a positive one, but I would love to explore this deeper! Let me know if you have any insights on this topic :)