How many of the sockeye that are sold each year from the lucrative commercial sockeye fishery are tainted with PCB's?
All of them! The usual ocean water contains about 0.5 micrograms of PCB's per pound and this accumulates in the sockeye as they feed and grow. The meat of the average sockeye contains around 20 micrograms of PCB's per pound, mostly concentrated in the fat. Maybe one should eat salmon skinless like many health conscious folks do with chicken.
What concentration of PCB's would you guess might be found in chicken?
How about in butter or enchiladas?
For perspective - If the concentration PCB's was similarly duplicated with LSD, one of the most potent psychoactive substances known, a street dose would be about 25 pounds of fish eaten at single sitting.
Me thinks that mercury might be a bigger concern. I recommend that you abstain from fish altogether. Learn to subsist on tofu and nuts and leave the sockeye for those of us who appreciate their healthier aspects.