Recommended Reading / Viewing. 1  Your engine manufacturer's operating instructions. 2  Mixture Magic (John Deakin) 3  EGT, CHT, and Leaning (Mike Busch) 4  Leaning Basics (EAA/Mike Busch) (video) 5  Leaning: The Advanced Class (EAA/Mike Busch) (video)
PCBs are a probable human carcinogen. Studies of PCBs in humans have found increased rates of melanomas, liver cancer, gall bladder cancer, biliary tract cancer, gastrointestinal tract cancer, and brain cancer, [1] and may be linked to breast cancer. PCBs are known to cause a variety of types of cancer in rats, mice, and other study animals. [2].
PCB-contaminated sediments in lakes or rivers can slowly release PCB back into water, from which it eventually evaporates. In water, a small amount of PCBs may remain dissolved, but most stick to organic particles and bottom sediments. PCBs are taken up by small organisms and fish in water. They are also taken up by other animals that eat these aquatic animals as food. PCBs accumulate in fish and marine mammals, reaching levels that may be many thousands of times higher than in water. Farmed salmon contain higher levels of PCBs than wild ones.