PCBs, or PolychlorinatedBiphenyls, are a group of environmentally harmful compounds that used to beproduced in the United States. A PCBmolecule is any of 209 chemical compounds called congeners. For something to be classified as a PCB, oneto ten chlorine atoms must be attached to a biphenyl molecule.Aroclor”. Monsanto was the company that produced“Aroclor”. PCB’s used to be in just about everything. Whether it be plastics, paints, rubberproducts, coolants, electrical components or anything dealing with themanufacturing process. They are favorable in products for their thermal andchemical resistance. PCBs have a veryhigh boiling point, usually above 270 degrees Celsius. This is what makes them so useful for heatresistant applications. For this reasonthey were often used in high temperature lubricants. Many plastic parts for automobiles, and otherequipment that are close to a heat source such as an engine contained PCB’s. For the same reason, PCB’s were widely usedin electrical equipment. Transformersand lining of wires often require being I insulated with heat resistantmaterial. This requirement makes PCB’s aperfect match. While banned in many countries, like the U.S., Canada, and a lotof the European Union, many developing countries still use PCB’s in productionof their products. For the same reasons that make PCB’s souseful, they are also harmful to the environment. Because they are so resistant to heat andother factors, they also do not break down in the environment over time. This means that they accumulate at a veryrapid rate. This is particular evidentin our water ways. The animal that isconsidered to have the highest PCB concentration is the orca whale. But in more general terms, aquatic lifegenerally has the highest level of PCB’s. Predatory fish/mammals have the highest levels due to bioaccumulation. This is because they are eating lower lifeforms every day. The PCB’s that theirprey has absorbed is than brought into the body of the predatory animal. Because PCB’s do not break down easy, theystay in the animal’s body. This can havemany adverse health effects. Just someof the effects include mothers having premature births, cancer, heart disease,and pretty much anything else you can think of relating to a chroniccondition. Now this all sounds bad, noone wants animals to be sick. But theconcerning part about this is that humans are eating these animals. So we are also suffering from bioaccumulation. PCB’s are thought to have the same effect inhumans as on marine mammals. This isconcerning because such a large portion of the fish we eat come from the ocean. In particular salmon, which is apredatory fish. So if bioaccumulationshappening in salmon, it is even more magnified in humans, since we are actuallyeating a predator. Overall, we need tocompletely stop the use PCBs worldwide. It does not matter if the U.S. is no longer using PCB’s if other nationsstill are. PCB’s drift thousands ofmiles and spread all across the world in are oceans.