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Chlorine dioxide bleached pulp effluent causes genetic damage in
[Entered Greenbase July 14, 1997 ]
The Vancouver Sun July 14, 1997 Study links mill waste to genetic harm in
fish: A researcher calls the results of experiments near Prince George a
Pandora's Box for industry. Stephen Hume Serious genetic damage has been
found in baby chinook salmon exposed to low levels of supposedly
non-toxic pulp milleffluentsroutinely released into the upper
The findings have major implications for Canada's $20-billion
pulpand paper industry, which invested heavily in cleaning up
effluentsafter a long battle with environmental critics. It also
has implications for British Columbia's sport fishing industry.
The Fraser is a major producer of the chinook salmon, which is
the province's most prized game fish and the mainstay oftourism
based on saltwater angling.
``Yes, this really is a blockbuster finding. It's a Pandora's
Boxfor the industry,'' said geneticist Michael Easton, one of
four scientists who studied the effects of the effluents using
sophisticated diagnostic technology developed for human cancer
What they found was evidence that the DNA of the baby fish they
studied was being being altered. DNA, or deoxyribonucleic acid,
isthe building block of life. It contains biochemical codes
governingthe functions by which cells repair and replicate
DNA also programs sperm and egg cells with the instructions for
division that control the development of embryos. Damage to DNA
haslong been linked to cancer, mutations, birth defects
andreproductive failure. Scientists now worry there is a risk
that suchdamage can impair an organism's ability to survive
changing environmental conditions and could result ultimately in
``Genetic damage is particularly insidious because it can take
several generations for the effects to show up,'' Easton said.
Easton, of Vancouver-based International
BroodstockTechnologies,and George Kruzynski, Igor Solar and
Helen Dye, three scientists from the West Vancouver laboratory
of the federal department of fisheries and oceans' biological
sciences branch, began their studyin in 1995.
A paper formally documenting the research and its conclusions
hasjust been published in the scientific journal Water Science
and Technology. A second paper corroborating the findings of the
firstis in final preparation for publication.
In the study, juvenile chinook from a local hatchery were
exposedto effluents going into the river at Prince George and
then cellswere examined and genetic changes measured.
``Remember that we haven't demonstrated that this is going on in
the fish in the river,'' Easton said. ``And we
haven'tdemonstratedany changes in the actual germ [reproductive]
cells. What we havedemonstrated is that genetic damage to fish
in the river is a distinct possibility.''
Exactly what chemical in the effluent is responsible for the
genetic damage in the baby chinook is unknown, Easton said, but
thestudies show the damage to DNA can be increased either by
making concentrations stronger or by lengthening exposure time
to the sameconcentration of effluent.
Otto Langer, a federal scientist with the Fraser River Action
Plan,said he is not surprised the specific chemical cause has
not beenpinned down.
``When you look at a pulp mill effluent you're looking at maybe
10,000 compounds,'' Langer says. ``It's a complex soup.''
The findings, which Easton describes as ``just the initial
assay,the bare first step,'' are gloomy news for B.C.'s $5-
billion pulpand paper industry.
Problems associated with toxic effluents from pulp processing
weregenerally thought to have been solved by new pollution
control technologies and by new processes introduced at great
In fact, the effluents causing the genetic damage reported by
Easton currently meet all provincial and federal environmental
standards, of which B.C.'s are among the toughest.
The findings on the upper Fraser are doubly dismaying because
stringent provincial and federal regulations and enforcement in
British Columbia have resulted in remarkable progress
inreducingthe toxicity of pulp mill effluents.
In most cases the presence of cancer-causing dioxins and furans
hasbeen reduced to non-detectible levels. In fact, acute
toxicity ofeffluents has virtually been eliminated in B.C. mills
using the improved treatment processes.
The changes have been so effective that there has recently been
talk of relaxing some of the more stringent pollution control
The Prince George mill that was the subject of the new study
bleaches softwood pulp using chlorine dioxide and produces about
1,500 cubic metres of effluent per day. This is stabilized in a
settling pond and then discharged directly into the Fraser.
``This is state of the art technology for pulp mills,'' Easton
said, ``although it is not state of the art for waste water
The effluent discharged at Prince George is
consideredcompletelynon-toxic. Fish can survive for up to four
days -- the standard measure for toxicity -- in a pure solution
of the effluent, even atcold temperatures.
``The fact is that we're still in the stone age regarding
regulations,'' Easton said. ``We really have no idea what we're
Easton, who is calling for more intensive study, said this kind
ofhigh tech testing for genetic impacts should become a standard
partof environmental monitoring.
``We don't know what's actually happening at the genetic level.
It's extremely important that we find out. We have a profound
responsibility to start worrying about the genetic consequences
ofour actions. Clearly, the genetic effects are where we should
Other research has documented associations between exposure to
industrial chemicals and elevated risk of cancers, birth defects
andloss of fertility in the human population.
If these implications are true for migratory fish exposed to
``safe'' pulp mill effluents at such low levels, what might the
implications be for sedentary human populations exposed to the
chemicals -- even at extremely low levels -- over long periods
``What about genetic damage in the [mill] workers themselves?
Thereis so much work that needs to be done in this area. It's
now time toopen the box and let's get on with it,'' Easton said.
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[Entered Greenbase July 14, 1997 ]
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