Chief concerns are contaminants such as mercury , cancer-causing PCBs . ( Banned in the 1970s , PCBs still contaminate the environment . Health benefits of salmon seen to outweigh the risk posed by minute PCB levels . Pregnant women should avoid high-mercury swordfish , shark , tilefish , king mackerel . Comment:
Chief concerns are contaminants such as mercury , cancer-causing PCBs . Health benefits of salmon seen to outweigh the risk posed by minute PCB levels . Pregnant women should avoid high-mercury swordfish , shark , tilefish , king mackerel . Comment: