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Environmental Fate and Biological Effects of Polychlorinated Biphenyls (PCBs)

Environmental Fate and Biological Effects of Polychlorinated Biphenyls (PCBs). Gretchen DeBaun. General Information. Highly toxic persistent organic pollutants (POPs) Found world-wide Used predominantly as dielectric fluids in capacitors and transformers

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Environmental Fate and Biological Effects of Polychlorinated Biphenyls (PCBs)

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  1. Environmental Fate and Biological Effects of Polychlorinated Biphenyls (PCBs) Gretchen DeBaun

  2. General Information • Highly toxic persistent organic pollutants (POPs) • Found world-wide • Used predominantly as dielectric fluids in capacitors and transformers • Widely used from the 1920’s until they were banned in the 1970’s

  3. Structure • Consists of two connected phenyl molecules with chlorine attached to one or more carbons

  4. Congeners • There are 209 possible congeners which are formed depending on the position and number of chlorine atoms attached to the biphenyl ring structure. • One example is 4’4 - dichlorobiphenyl, an industrial pollutant. • Smaller, more reactive, and more volatile

  5. Human Exposure to PCBs • Generally occurs through inhalation, ingestion, dermal exposure. • Contaminated fish are the largest source of ingested PCBs

  6. American Federation of State, County and Municipal Employees (AFSME)Health and Safety Fact Sheet: • Transformers in buildings can leak. • Transformers can burn, altering the PCBs into much more toxic chemicals. • PCB spills or illegal dumping on roads • Capacitors used by electrical utilities on power lines can overheat and explode during power surges.

  7. Health Effects • Acute exposure: irritation of eyes, nose, and throat which can cause an acne-like rash called chloracne. • High exposure: liver and nervous system damage • Chronic exposure: reproductive and immune system problems • Possible human carcinogen

  8. PCBs in the Environment • Transported by a variety of natural and artificial means • Easily absorbed into soil and sediment • High organism bioavailability and bioaccumulation

  9. ·Degree of concentration in each level of the Great Lakes aquatic food chain for PCBs (in parts per million, ppm). The highest concentrations are found in the eggs of fish-eating birds. goawayallied.org/bio.htm

  10. Polychlorinated Biphenyls (PCBs) in Poland (Water Reservoirs, Bottom Sediments and Sludge) • International Odra Project • Samples collected between 1997 – 2000 from the Odra River and its tributaries, after a flood in 1997 • Department of Water Pollution Control in Gdańsk • Collected PCB samples from sediments of different sites of the Odra and its tributaries during 1998-2002

  11. Degradation of PCBs • Extremely resistant to chemical, photochemical and biological degradation due to their high chemical stability (Grabowska, 2009) • The newest trend in destroying PCB waste is application of non-combustion technologies instead of incineration or high temperature pyrolysis. (Grabowska, 2009) • Dechlorination and photocatalyticdegragation

  12. Metabolism and Detoxification • The liver is the primary site of PCB metabolism • Rate of detoxification depends on the number of chlorines present on a specific congener • detoxified anaerobically if there are more than four chlorine atoms present and aerobically if there are zero, one, two, or three chlorines present

  13. References • AFSCME Health & Safety Fact Sheet: PCBs. American Federation of State, County and Municiple Employees. 2010; http://www.afscme.org/issues/1321.cfm • Ashley A. Raeside, Sarah M. O’Rourke, Ken G. Drouillard. Environmental Toxicology and Chemistry. New York: Feb 2009. Vol. 28, Iss. 2; pg. 434, 12 pgs • Dr S. Dobson, Dr G.J. van Esch. INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY. World Health Organization. 1993 • GreenFacts Scientific Board. GreenFacts Sheet. 2009. http://www.greenfacts.org • Kimberly Gehle, MD, MPH; Darlene Johnson, RN, BSN, MA; Felicia Pharagood-Wade, MD, FACEP; Lourdes Rosales-Guevara, MD. Agency for Toxicity and Disease Registry. Sep 2006. • NSDL. Decachlorobiphenyl is a PCB which was found to be an industrial pollutant. U.S. National Science Foundation. 2009 • Roland Wall. The Academy of Natural Sciences. Feb 2002 • U.S. Environmental Protection Agency. March 2009. http://www.epa.gov/epawaste/hazard/tsd/pcbs/pubs/about.htm • http://goawayallied.org/bio.htm • Grabowska, Iwona , Polish Journal of Environmental Studies, Polychlorinated Biphenyls (PCBs) in Poland: Occurrence, Determination and Degradation.19:1, 7(7). 2010

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