THE EDUCATION OF SHANNON
WHAT IS TCE AND WHAT HEALTH
EFFECTS ARE ASSOCIATED WITH IT?
TCE or trichloroethylene is a colourless liquid at room
temperature with an odour similar to ether or chloroform.
It is a man-made chemical that is mainly used as a solvent
to remove grease from metal parts. It is used in the automotive
and metals industries. It is also used as a chemical (building
block) to make other chemicals.
TCE: WATER WOES
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TCE evaporates readily from surface water but may be found
in groundwater. It can be introduced into groundwater
as a result of industrial effluents or spills or leaking
from old dumpsites. Canadians can be exposed to TCE through
its presence in drinking water, air and food. Certain
segments of the population could be exposed via contaminated
soil or occupational settings.
TCE is still used as a solvent to clean metal parts, but
its use has decreased. TCE is not manufactured in Canada,
and The Solvent Degreasing Regulations under the Canadian
Environmental Protection Act of 1999, which came into
force in July, 2003, are designed to significantly reduce
the use and release into the environment of TCE in Canada.
Recent studies suggest a link between long-term exposure
to high levels of TCE and cancer. Studies also indicate
a possible link between exposure to TCE and potential
reproductive effects associated with fetal heart development.
Animal studies have shown links to kidney and testicular
tumours in rats and pulmonary and liver tumours in mice.
Based on both animal and human studies, TCE has been classified
as probably carcinogenic to humans.
To find out more about TCE, you can visit the Agency
for Toxic Substances and Disease Registry website.
CANADA AND THE REST OF THE
WORLD
The maximum allowable level of TCE in drinking water
is often measured in parts per billion (ppb). It is
Health Canada’s responsibility to set a guideline
for a maximum allowable level, but it is only a guideline.
Monitoring water quality is a provincial jurisdiction,
unless it is on federally owned land. Canada’s
maximum allowable level is 50 ppb. This is higher than
some other industrialized countries. For example, the
United States sets its limit at 5 ppb, the European
Union at 10 ppb and Australia at 30 ppb.
Following the TCE contamination in Shannon and the high
levels found in some homes (1000 ppb), the Quebec government
reduced the maximum allowable level to 5 ppb and now
Health Canada is thinking about doing the same.
Health Canada recently completed a review of the health
risks associated with TCE in drinking water. This review
factored in routes of exposure to TCE via drinking water
in addition to ingestion – through inhalation
and skin absorption, from showering and bathing. It
assessed all identified health risks, taking into account
new studies and approaches. Based on this review, Health
Canada is proposing that the guideline be changed from
50 ppb to 5 ppb.
During its October 2003 meeting, the Federal-Provincial-Territorial
Committee on Drinking Water reviewed the proposed revised
guideline and approved that it undergo public consultations.
To find out more about TCE and water quality in Canada,
you can visit Health
Canada’s website.
OTHER FEDERALLY CONTAMINATED SITES
In addition to Canadian Forces Base Valcartier, the
federal government owns over 1,700 other contaminated
sites across Canada. The sites range from abandoned
mines in the north to the water off the coast of Nova
Scotia. The contaminants at these sites vary as well,
from heavy metals to PCBs and PAHs.
The Treasury Board of Canada Secretariat produces a
listing of all known federal contaminated sites. The
list can be viewed by government department, by province
and territory or by city.
If you want to check what federal contaminated land
can be found where you live, you can check the Treasury
Board of Canada website.
Canada’s environmental watchdog, Johanne Gélinas,
who is formally known as Canada’s Commissioner
of the Environment and Sustainable Development has been
very critical of the federal government and how it has
handled the clean up of federally contaminated sites.
She wants one central authority to be responsible for
coordinating the cleanup of all these lands, and she
also wants the government to assess and prioritize the
worst sites in Canada so that they can be cleaned up
first. In her 2002 annual report, the Commissioner dealt
specifically with what she saw as problems regarding
the clean up of federally contaminated lands.
If you want to take a look at her recommendations and
various government departments’ responses
here.
OTHER INTERESTING WEBSITES
If you want to find out more about Woburn, Massachusetts,
and the story behind the book A Civil Action by Jonathan
Harr, and the movie, starring John Travolta, you can
visit: North
Shore Online.
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