12 May 2010
Polar bear in East Greenland. Photo: Rune
Dietz/NERI
A cocktail of industrial
chemicals damages the bones and organs of
polar bears, their immune system and their
reproduction. However, the extent of the
detrimental effects remains unknown, concludes
senior scientist Christian Sonne, National
Environmental Research Institute (NERI),
Aarhus University, having conducted the
first overall review of the last 10 years’
research into the impact of pollution on
the health of polar bears.
Christian Sonne’s review
has just been published in the scientific
journal “Environmental International” and
includes his and his colleagues’ widely
published research within the area. NERI
and the Greenland Institute of Natural Resources
are responsible for the research in Greenland.
Additional cooperation exists with colleagues
in Denmark, Norway, USA and Canada.
Industrial chemicals
such as brominated flame retardants, PCB
and polyfluorinated substances that are
used in several everyday products and as
softeners and for surface treatment are
transported with heavy metals, including
mercury, with air and sea currents and in
sea mammals to the Arctic from the industrial
part of the world.
In the Arctic the contaminants
enter the marine food chain and are accumulated
in the fat tissue of seals and small whales,
prey animals of the polar bear. And, next,
in the polar bears themselves.
In his review Christian
Sonne concludes that these environmental
contaminants result in a number of so-called
subclinical diseases in the animals.
“These are diseases
that are not immediately lethal, but which
may lead to the development of more chronic
diseases and which at some level or other
will impact the immune and reproduction
systems of the animals,” he says.
So far, Christian Sonne
has analysed tissue and bone (skull) samples
from approx. 100 out of 200 East-Greenland
polar bears shot by hunters in the Scoresbysund-area.
Together with the Greenland
Institute of Natural Resources NERI has
since 1983 co-operated with hunters harvesting
polar bears at a sustainable level of 1-2%
annually of the total East-Greenland population
of ca. 2,000-3,000 animals.
High-quality collection
of tissue and skulls
“Our co-operation with the hunters has resulted
in a unique high-quality collection of tissue
and skulls, and the East-Greenland polar
bear project is among the hitherto largest
investigations elucidating pollution and
health effects on the organ systems of wild
mammals,” says Christian Sonne.
Monitoring and observations
of polar bears have also comprised the Svalbard
population, and Christian Sonne and his
colleagues have in the past undertaken controlled
experiments on the impact of environmental
contaminants on farmed polar foxes and Greenland
sledge dogs. Both species are at the top
end of the Arctic food chains.
The animals were divided
into two groups, one was fed with food containing
environmentally hazardous substances, the
other acted as control.
The experiments documented
that the group of animals impacted by hazardous
substances via their food suffered damage
to their health.
"For polar bears
it cannot be concluded that there is a cause
and effect relative to environmental contaminants
and state of health, but the experiments
with polar foxes and sledge dogs support
the theory that there may be such a connection,”
states Christian Sonne, who emphasises the
importance of understanding that all the
organs and systems of the polar bear function
in harmony.
Health effects from
long-range transported contaminants in Arctic
top predators: An integrated review based
on studies of polar bears and relevant model
species. Sonne, C. 2010. Environment International.
Elsevier - p. 31.
+ More
Christian Kjær
new research director of Department of Terrestrial
Ecology
3 May 2010 - Christian
Kjær has been appointed new director
of research in the Department of Terrestrial
Ecology, National Environmental Research
Institute (NERI) at Aarhus University. Christian
Kjær comes from a position as senior
scientist and head of section in the same
department. He was previously employed as
head of the nature department in Viborg
County.
In 1991Christian Kjær
graduated as a biologist from Aarhus University,
where he also received his PhD in 1994.
He was subsequently employed as a scientist
and later senior scientist at NERI in Silkeborg.
In 2005 he was appointed head of the nature
department in Viborg County and was responsible
for monitoring activities, nature conservation,
stream maintenance and administration in
relation to stream and nature protection
regulations. In 2007 he returned to NERI
as senior scientist.
Throughout his career,
Christian Kjær’s research activities
have focused on plants and insects and their
mutual interaction, particularly in relation
to their effect of pesticides on non-cultivated
land. He has recently contributed to the
development of a pesticide risk indicator
(PestNaB). His research has formed the basis
for advising on risk and impact assessment
of pesticides, genetically modified plants
and heavy metals.
With his new appointment,
Christian Kjær hopes to be able to
focus on the need for knowledge on measures
to improve biodiversity, the need for a
scientifically systematic approach to risk
assessment of new technologies in Denmark
such as, for example, nanotechnology and
the need for cross-disciplinary cooperation
relating to the environmental challenges
facing society.
Christian Kjær will take up his new
position at NERI on 1 May. He replaces Hans
Løkke who has decided to retire.
