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