Overall, they include drugs that have long been abused, such as marijuana and cocaine, and drugs whose abuse is a more recent development. Some are stimulants, some depressants, and some hallucinogens-while most exhibit multiple pharmacological properties.
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].
Background PCBs are mixtures of synthetic organic chemicals that were commonly used for various applications from approximately 1929 until 1979 when the U.S. banned PCB manufacturing, processing, distribution, and use (EIP Associates, 1997). PCB FACT SHEET.CP.8-6-03.DOC equipment and appliances such as hair dryers, air conditioners, refrigerators, power tools, and submersible well pumps. Also includes capacitors used in appliances and electronics such as televisions and microwave ovens.