Porphyria Educational Services
PORPHYRIA EDUCATIONAL SERVICES BULLETIN
Vol. 1 No. 29 July 17, 1999
FOCUS: The Chemical Toxin PCB
Exposure to PCBs [polychlorinated biphenyls] still remain a
major trigger to porphyria patients. Among the thousands of contaminants
found in the environment, few are as well recognized or more feared by the
public than polychlorinated biphenyls (PCBs). PBCs have contaminated thousands of miles
of rivers and streams, and lakes worldwide.
Rivers of New York, and dozens of marine and fresh water harbors
of both the Pacific and Atlantic coasts and the Great Lakes are filled with
PCBs. Removal of PCBs from the environment are estimated to cost billions
of dollars in the U.S. alone.
What are PCBs?
PCBs are a class of chlorinated organic compounds that were
manufactured by the Monsanto corporation during the years 1930 to late in
the 1970s. These substances were widely used throughout the world
until health officials and researchers began to suspect that the compounds
caused serious human health effects. It is esti mated that during the
approximate 40 years of production, more than 700,000 tons of PCBs
were manufactured in North America.
Why were PCBs so popular?
Because of its unique heat resistance and electrical
characteristics, the compound was widely used as an additive in transformer
and hydraulic fluids and continues to be used in a variety of applications
throughout the world.
This class of contaminants is made up of multiple compounds.
This can consists of more than 200 individual chemicals, each with a
different number and arrangement of chlorines around a central carbon double ring, or
biphenyl. PCBs in the environment can include 70-90 unique chlorinated compounds or
congeners, each with their own characteristics and behavior.
Even though this class of contaminants is considered to be
insoluble in water and was not thought to readily volatilize to the atmosphere, the
compound is found in remote areas of the world, thousands of miles from
sources. That means the compound is highly mobile and can be readily
transported by water and air. PCBs yet can be found in almost every living
organism on Earth, including humans.
The subtle effects of PCBs.
Exposures to contaminants like PCBs can have long term effects.
It is becoming increasingly evident that exposure to small of PCBs over time
affects the central nervous systems of humans and their children, resulting
in learning and behavioral problems.
For humans, learning andbehavioral problems translate into
children and adults who are less able to cope and therefore require long
term assistance and maintenance.
Estrogenic compounds have also been linked to increased
incidences of breast cancer, and research is currently being conducted to
determine whether these substances may be tied to increased cancers in
exposed women. PCBs are also suspected of affecting thyroid function. All of
these suspected chronic effects occur at very low exposures and although the
impacts may not be readily apparent or obvious, they can be as devastating
as those resulting from acute exposures. The effects of contaminant exposure
are difficult to measure yet there is growing evidence based on studies, that
PCBs and a host of other environmental contaminants, are having an impact on
humans that extends far beyond what has been recognized to date.
For the porphyric patient exposure to PCBs is an invitation to
triggering acute attacks.
Just as the availability of PCBs differs with the amount of
chlorination, the effects varies with the degree and position of the chlorine in the
compound. Because PCBs are some of the most persistent environmental
contaminants, they accumulate in living organisms and can cause human
There are historical incidences of acute exposures to humans
that resulted in serious health impacts. PCB-contaminated food developed
skin pigmentation problems as well as central nervous system disorders.
Because PCBs are stored in fat tissue, porphyrics when losing
weight or exercising and sweating tend to lets tores in the fat go into the
blood stream. Upon entering the bloodstream, the PCBs then may trigger
acute attacks by increasing the production of porphyrins in the liver.
Once exposed to the PCBs the PCBs remain in the body
until the stored fat is eliminated through weight loss or extreme sweating
PCB's range in appearance from colourless, oily liquids to
more viscous and increasingly darker liquids, to yellow and then
black resins, depending on chlorine content. Viscosity varies from
high mobile to very thick and syrupy. by standard test. The vapour is
invisible and there is a characteristic strong odour.
You should NEVER smell the vapours in order to identify
PCBs. All inhalation should be strict;y avoided.
PCB's used a dielectric fluids are usually mixed with
organic solvents such as chlorinated benzenes which change the
chemical and physical properties of the fluids. In addition used PCB
fluids may be contaminated with dirt, moisture, black carbon
particles and pieces of insulation from the inside of the equipment.
This contamination may change the appearance of the fluids.
How to test simply for PCBs.
PCBs are heavier than water whereas mineral oils are lighter
than water. This can be used as a simple test to help identify
Simple testing for Chlorine
1.Heat one end of a length of clean un-coated heavy copper wire
(preferably 2 to 3 mm diameter) in a pale blue gas flame. If the wire is
initially clean there will be no colouration of the flame until the copper
reaches red heat when an orange hue will be imparted to it.
2. Allow the wire to cool, somewhat below re heat, then dip
it in the unknown chemical and again heat it. There may be an
initial bright yellow and smoky flame - but as the copper nears re heat,.
The presence of chlorine will be indicated by a bright green colouration
(the yellow should have disappeared at this stage), as it reacts with the
copper to produce copper ions in the flame.
Please NOTE: When PCBs are decomposed at high temperatures, gases
are produced which contain a high proportion of hydrogen chloride, a highly
irritating and corrosive chemical. Therefore, please
remember to conduct these tests in a well ventilated place.
As with most products there are various trade names for the
manufacturer;'s products. PCB fluids are often known by the term askarel.
ASKAREL is a generic name for synthetic electrical insulating material.
Askarels generate only non-explosive gases or gaseous mixtures when
decomposed by an electric arc. Commercial mixtures contain PCBs,
chlorinated benzenes and contaminants, in a range of concentrations.
Manufacturers have used a wide variety of trade names,
NO - FLAMOL
Santothern, Therminol. Pydraul