Environmental Fate and Biological Effects of Polychlorinated
Biphenyls (PCBs)Gretchen DeBaun
General InformationHighly toxic persistent organic pollutants
(POPs) Found world-wideUsed predominantly as dielectric fluids in
capacitors and transformersWidely used from the 1920’s until they were
banned in the 1970’s
StructureConsists of two connected phenyl molecules
with chlorine attached to one or more carbons
CongenersThere 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
Human Exposure to PCBs Generally occurs through inhalation,
ingestion, dermal exposure. Contaminated fish are the largest source of
ingested PCBs
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.
Health EffectsAcute 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
PCBs in the EnvironmentTransported by a variety of natural and
artificial meansEasily absorbed into soil and sedimentHigh organism bioavailability and
bioaccumulation
·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
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
Degradation of PCBsExtremely 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 photocatalytic degragation
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
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