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].
Other studies have also shown that PCBs cause liver tumors (EPA 1996). One study, conducted by the National Cancer Institute (NCI) in 1978, found that a commercial PCB mixture caused a rare type of stomach tumor (gastric adenocarcinoma) in 6 of 144 exposed rats.