Contents - Winter 2008
Vol. 1 No. 1
Detoxing the World Environment
By Michael Robin
When John Giesy was a boy growing up in Michigan, his
mother kept the refrigerator outside. To have kept the
appliance indoors would have been to invite disaster, as early
models contained ammonia, which would be deadly in an
enclosed space.
“They invented a safer chemical—a miracle chemical. Guess
what it was? CFCs,” says Giesy, now an environmental
toxicologist at the University of Saskatchewan.
Decades later, widespread use of CFCs
(chlorofluorocarbons) has caused thinning of the Earth’s
ozone layer, exposing the planet to greater levels of harmful
ultraviolet radiation from the sun.
It’s a scenario Giesy says has played out time and again.
Chemicals used in industry are blamed for disrupting
body systems in everything from fish to people. PCBs, for
instance, were introduced as a safety measure to prevent
electrical transformer fires, but they were later found to
disrupt immune systems and cause cancer.
Giesy, who holds a Canada Research Chair in
Environmental Toxicology, is one of the world’s foremost
authorities on the subject. His aim is to identify man-made
chemicals in the environment, find out if they are doing
any harm, and help develop benign or less harmful “green”
alternatives.
John Giesy. Photo courtesy John Giesy.
Knowledge produced through research is essential to
creating sound public policy, Giesy says.
For example, chlorine has been widely used for decades
to disinfect drinking water. Chlorination, however, also
produces cancer-causing chemical compounds called
halomethanes. Public fears prompted officials in Peru to
stop chlorinating the water, which soon resulted in a cholera
outbreak that killed 3,000 people.
For Giesy, a knowledge gap was behind the tragedy. Yes,
chlorinated compounds in water cause cancer, but the risk of
cholera is much higher. With complete information, public
officials could have weighed the risk of thousands of deaths
from cholera today against a few extra cases of cancer spread
over several decades.
“We make these decisions, often based on perceptions
without complete information,” Giesy says. “In part, my job
is to do the science to get the information and then educate both the public and the students.”
Giesy arrived at the U of S campus in 2006, lured by the
promise of a rapidly growing research and education
program at the U of S Toxicology Centre.
Led by Karsten Liber, another environmental toxicologist
and the centre’s director, the program offers such
innovations as pairing senior undergraduate students with
scientists to incorporate research early on in their education.
Well known for its work with northern ecosystems, the
Toxicology Centre became the focus for the Northern
Ecosystems Toxicology Initiative which was identified as
a priority area by the U of S in 2000. This was reaffirmed
in 2007 with the opening of a $12-million expansion that
included new labs and analytical equipment. Over the next
few years, more than 50 researchers and support staff will
join the core group of 14 researchers currently at the centre.
“We are the largest—and probably best—comprehensive
environmental toxicology program in North America and
one of the top few in the world,” Giesy says. “We are number
one. The challenge is to stay there.”
Giesy is working with university and industry partners to
help make this happen. The strategy is to generate revenue
from techniques and technologies developed at the centre.
For example, his team has developed a fast, cheap assay to
test for endocrine (hormone) disruptors in the environment.
There are an estimated 85,000 chemicals that may have such
effects, and a shortlist of 15,000 has been identified by the
international Organization for Economic Co-operation and
Development (OECD). The OECD has put the Giesy assay
forward for adoption as the international standard for such
testing.
Another possible revenue generator is a process that
could drastically reduce the enormous amount of water
required by Alberta’s booming oil sands industry—a major
environmental concern. Giesy’s group has developed a
patented process to recover oil from oil sands.
“We get 99-per-cent-plus efficiency, at room temperature,
with no water,” Giesy says. “The process also works to
remove naphthenic acids from the waste water—which is a
big problem. Nobody else knows how to do that.”
“We are the
largest—and
probably best—
comprehensive
environmental
toxicology program
in North America
and one of the top
few in the world,”
Giesy says. “We are
number one. The
challenge is to stay
there.”
The proceeds from these technologies will be used
to fund the centre’s research programs, bursaries
and scholarships. They will also insulate the
program from fluctuations in funding received
from traditional government and granting agency
sources.
But research in the field of environmental
toxicology is more than a matter of self-interest—it is an international responsibility, Giesy stresses.
He points out that North Americans enjoy
inexpensive goods made in China but the low
prices are made possible in part by a lack of
effective environmental regulations. This harms
the people of that country, who must live in
some of the most polluted cities on Earth. And
pollution respects no borders—toxins released in
Asia can end up in the traditional diets of Inuit in
Canada’s North.
“So goes China, so goes the world environment,”
Giesy says.
He takes this international responsibility
personally, transferring knowledge directly via
faculty positions at City University in Hong Kong
and Nanjing University in mainland China.
He makes frequent visits to China to advise
government researchers and officials.
“We make presentations, we do training, we bring
[Chinese] scientists here,” he says, noting that
the U of S as an institution is currently working
to build strategic partnerships with Chinese
universities on a variety of fronts.
“We teach the teachers. We’re trying to imbue
them with an environmental ethic to go back and
have an impact in their own country.”
Prof. Giesy and graduate student Rita Seston on a research field trip in Michigan where they are studying concentrations of dioxins in blood of great blue herons. Giesy’s team has found traces of industrial chemicals in wildlife around the world, from frogs and trout to eagles and blue herons.
Green ‘chips’ and POPs
In 2000, U.S. chemical giant 3M Corporation
announced it was voluntarily abandoning some
extremely useful and popular product chemistries.
The move to abandon a class of chemicals known
as perfluorinated chemicals was taken in part due
to co-operative research with John Giesy, one of
the world’s top toxicologists.
Giesy, who was then at Michigan State University,
and his colleagues found perfluorinated
chemicals in wildlife tissue samples from all over
the world—from Ganges river dolphins to North
American bald eagles.
The perfluorocarbons were in quantities less than
those needed to cause adverse health effects
in the animals. Still, something had to be done.
Perfluorocarbons can accumulate in living things,
interfering with cell metabolism and causing
toxic effects. They also are extremely difficult to
break down in the environment, putting them
in a group of chemicals called persistent organic
pollutants (POPs).
“But the critical thing was, they were important
components of many useful products, some of
which are critical to the current way of life and the
global economy, such as microchips,” he says.
For instance, perfluorocarbons have highly
valuable properties such as the ability to repel
both water and oil. Their usefulness has made
them a great success in the marketplace.
“They’re used in paint, cement, surface coatings,
fabric, paper coatings such as microwave popcorn
bags, all sorts of health and beauty products, you
name it,” Giesy says.
Fortunately for the world’s environment—and its
economy—Giesy is more than a toxin sleuth. He
is a master of “green chemistry” – finding more
benign alternatives to harmful human-made
chemicals.
In the case of the offending perfluorocarbons,
Giesy and his team used a technique called
quantitative structure activity relationships,
or QSARs. What they found was that
perfluorocarbons with eight carbon atoms in
their chain-like structure were extremely toxic, but
anything with five carbons or less was fine.
“The simple solution was to use C4 (four carbon)
chemicals,” Giesy says. “So they were able to
replace everything, and you could still buy
Scotchgard—the can looks the same—but
the chemical in there, the active ingredient, is
different.
“Society can have the benefits of useful products
with less potential risk to humans and the
environment—a win-win-win situation".
