[ RadSafe ] Article: Chernobyl ecosystems 'remarkably healthy'

[John Jacobus]

>From Nature:  
Published online: 9 August 2005

Chernobyl ecosystems 'remarkably healthy'
Michael Hopkin
 
Despite high radioactivity, plants and animals seem to
be thriving. 
 
Chernobyl's ecosystems seem to be bouncing back, 19
years after the region was blasted with radiation from
the ill-fated reactor. Researchers who have surveyed
the land around the old nuclear power plant in
present-day Ukraine say that biodiversity is actually
higher than before the disaster.

Some 100 species on the IUCN Red List of threatened
species are now found in the evacuated zone, which
covers more than 4,000 square kilometres in Ukraine,
Belarus and Russia, says Viktor Dolin, who studies the
environmental effects of radioactivity at the
Ukrainian National Academy of Sciences in Kiev. Around
40 of these, including some species of bear and wolf,
were not seen there before the accident.

If animals at the top of the food chain are present,
then the plants and animals they eat must also be
thriving, says ecologist James Morris of the
University of South Carolina in Columbia, who chaired
a panel of scientists presenting the results at a
meeting of the Ecological Society of America in
Montreal, Canada, this week.

"By any measure of ecological function these
ecosystems seem to be operating normally," Morris told
news at nature.com. "The biodiversity is higher there
than before the accident."

Mutant die-off

How has this happened, given that radiation levels are
still too high for humans to return safely? Morris
thinks that many of the organisms mutated by the
fallout have died, leaving behind those that have not
suffered problems with growth and reproduction.
 
"It's evolution on steroids. There are a lot of
deleterious mutations in species but these seem to be
very quickly weeded out," Morris explains. Many young
fish living in the reactor's cooling ponds are
deformed, but adults tend to be healthy, implying that
those harmed by radiation die young.

Another factor in the ecosystem's apparent good health
could be that the major radioactive elements in the
region, such as caesium-137, tend to stay in the soil
rather than accumulating in plants and animals,
suggests Dolin. This means that contamination of the
human food chain by radioactivity from Chernobyl might
not be as severe as was feared.

All this has led some people to propose that tourism
to Chernobyl would help develop the area. In 2002, a
United Nations report suggested that ecotourism could
help plug the gap left by dwindling funds for
regeneration. 

A nice place to visit

It is now possible to visit the area on holiday. But
this doesn't mean that people can live there. Some 40
different radioactive elements, including strontium-90
and decay products of uranium and plutonium, were
released into the exclusion zone, and it will be many
hundreds of millennia before humans could move safely
back, Dolin says.

Humans spending long periods of time there would
suffer a build-up of radiation that would shorten
lives and raise newborn mortality. "It would be a
disaster for humans," Morris says.

Many birds are also showing the harmful effects of the
fallout. Morris's colleague Timothy Mousseau found
that barn swallows nesting around Chernobyl have lower
survival rates, fewer eggs and are in generally worse
condition than those living southeast of Kiev, away
from the exclusion zone.

It is difficult to say what will become of the
region's plants and animals, admits Morris. One way to
find out is to sample the genetics of populations to
see whether diversity is likely to continue to
increase. "What will happen here? That's the
question," he says. "In a way it's a fantastic
experiment."

Story from news at nature.com:
http://news.nature.com//news/2005/050808/050808-4.html

 
  © 2004 Nature Publishing Group | Privacy policy 

+++++++++++++++++++
"Every now and then a man's mind is stretched by a new idea and never shrinks back to its original proportion." -- Oliver Wendell Holmes, Jr.

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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