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| PCB Transformers - http://mrg.bz/wrBCzJ |
Have you ever seen one of these old transformers on a pole near your home? Can they be hazardous? Have you heard of PCBs but wanted to know more? Well you've come to the right place!
Polychlorinated Biphenyls, or PCBs as they are commonly known, are man-made chemicals that have become well known due to the environmental affects caused by bioaccumulation, particularly in Lake Ontario (Glooschenko & Glooschenko, 1975, Oliver & Niimi, 1998). They did not exist in natural environments until they were first made in the 1900’s (Barbalace, 2003). So there off to a rough start.
Polychlorinated Biphenyls, or PCBs as they are commonly known, are man-made chemicals that have become well known due to the environmental affects caused by bioaccumulation, particularly in Lake Ontario (Glooschenko & Glooschenko, 1975, Oliver & Niimi, 1998). They did not exist in natural environments until they were first made in the 1900’s (Barbalace, 2003). So there off to a rough start.
PCBs were used in many products prior to the 1960s
because of the physical properties of the chemical, which include being:
non-flammable, insulating, persistent, and chemically stable (United States
Environmental Protection Agency, 2013). However in the early 1970s, the toxic
properties of the chemicals were identified which resulted in the
reclassification of PCBs to that of a widespread contaminant (Glooschenko &
Glooschenko, 1975). Yikes! Following reclassification, landfills and disposal
companies had to rethink their use of the chemicals due to greater cost and
changes associated with new regulations and handling procedures (Province of
Alberta, 1996). This change, and greater awareness of health concerns drove the
commercial and consumer use of PCBs down drastically.
PCBs bio-accumulate in the environment, meaning
that once they are present they are very hard to remove. The effect of which is
an accumulation of the chemical over time. An example of this seen in Lake
Ontario, as the contamination of microscopic organisms in the lake led to the
buildup of PCBs in larger bony fish, rendering them unfit for human consumption
by Health Canada guidelines (Glooschenko & Glooschenko, 1975, Oliver &
Niimi, 1998).
PCBs are still in use today, particularly for
industrial purposes such as transformers (see picture above), and in old commercial products such as light ballasts
(United States Environmental Protection Agency, 2013). The case of PCBs should
be viewed as a lesson to future generations that will undoubtedly utilize
chemical compounds without knowing all of the potential consequences.
References:
Barbalace, R. C. (2003). The chemistry of
polychlorinated biphenyls. Accessed on-line: http://EnvironmentalChemistry.
com/yogi/chemistry/pcb. html.
Glooschenko, V., & Glooschenko, W. (1975). Effect
of polychlorinated biphenyl compounds on growth of Great Lakes phytoplankton. Canadian
Journal of Botany, 53(7),
653-659.
Oliver, B. G., & Niimi, A. J. (1988).
Trophodynamic analysis of polychlorinated biphenyl congeners and other
chlorinated hydrocarbons in the Lake Ontario ecosystem. Environmental
science & technology, 22(4), 388-397.
Province of Alberta. (1996). Waste Control Regulation.
Retrieved October 22, 2014 from
http://www.qp.alberta.ca/documents/Regs/1996_192.pdf
United States Environmental Protection Agency. (2013).
Polychlorinated Biphenyls (PCBs). Retrieved October 20, 2014 from http://www.epa.gov/wastes/hazard/tsd/pcbs/about.htm
