Sunday, March 16, 2008

Jenna, Recycled PCBs

PCBs are usually released in the environment during production, use, storage, and disposal. PCBs are considered to be an environmental contaminant because of their widespread use, along with some other reasons. In 1977, production of PCBs came to an end because the harmful effects that it caused. Many that could not be controlled quickly became terminated, but some can still be found in electrical transformers. It has been discovered that if PCBs "are released in the environment, PCBs persist for years because the molecules are so resistant to breakdown by chemical or biological agents." Though, PCBs are not soluble in water, there are still some that are found in surface waters that are constantly being transported back to the land and water. Some PCBs have even been transported worldwide and have been found on the ocean floors! The levels of PCBs will continuously be recycled back in through the land, water, and air for hundreds of years.

PCBs: polychlorinated biphenyls stands for a group of industrial organochlorine chemicals that became a major environmental concern. Must not be mistaken for pesticides.

I thought this supplementary section was actually quite interesting especially after reading the sections that came prior to this one. It seemed to make more sense. Though, it is still a bit difficult for me to fully grasp what PCBs actually are and how they came about. I do not think the book explained them as well as they probably could have, but what I do understand of them makes it an interesting and informative read. The picture that the book provides of how PCBs are recycled was extremely helpful. It illustrates, better than the book described, the whole recirculation process of PCBs.

Baird, Colin. "Chemistry in Your Life." Second Edition. W.H. Freeman and Company,
New York: 2006. 399-400.

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