[ RadSafe ] Fish-to-Fish Transmission of Radiation-Induced Stress

[Leo M. Lowe]

Hi,

Check out this interesting study in Env. Sci & Tech.  (I am not sure 
if this was already discussed on Radsafe.)

Search Google for "ES&T radiation sickness" to find the article.

L. Lowe
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Science News, September 20, 2006

Can You Catch Radiation Sickness?

Trout hit with radiation make other fish sick.

Call it startling and counterintuitive, but researchers report that a 
trout hit with X-rays can make other fish come down with 
<http://en.wikipedia.org/wiki/Radiation_sickness>radiation sickness. 
The results, published on ES&T's Research ASAP website (DOI: 
<http://dx.doi.org/10.1021/es061099y>10.1021/es061099y), may help 
regulators identify leaks from nuclear power plants.
Bystander effects from radiation have been found in multiple animals, 
including rainbow trout.

For the study, researchers set a tank holding a single rainbow trout 
in front of an X-ray machine and gave the fish a nonfatal dose of 
radiation. This fish was then placed in a tank for 2 hours with 
another trout that had not been X-rayed. But when the apparently 
healthy fish was later examined, some cells in its organs had died, 
and others began to express proteins as if the fish had been irradiated.

<http://www.chairs.gc.ca/web/chairholders/viewprofile_e.asp?id=1293&>Carmel 
Mothersill, a professor of radiation biology at McMaster University 
(Canada) and the lead author of the study, says that the results are 
not that surprising. Since 1921, researchers have detected biological 
effects in cells that have received signals from cells that were 
exposed to radiation. The science on this phenomenon, called 
<http://www.eurekalert.org/features/doe/2001-07/danl-rbe060702.php>the 
bystander effect, was ignored for decades, says Mothersill, until 
more studies reached a cumulative mass in the mid-1990s.

"The weight of evidence is now shifting," says Mothersill. She points 
out that her study was heavily funded by the nuclear industry, which 
is interested in understanding the effects of low-dose radiation in 
order to plan for any potential regulations in the future. The study 
sought to mimic what might happen if a nuclear power plant had a small leak.

<http://molecularmedicine.umaryland.edu/faculty/default.asp?ID=195>Bill 
Morgan, director of the Radiation Oncology Research Laboratory at the 
University of Maryland, says that he finds the study both fascinating 
and puzzling. But he finds it counterintuitive and does not 
understand how a healthy animal can become sick when it was never 
exposed to radiation. He has tried and failed to replicate an earlier 
study by Mothersill, with irradiated cells placed in a dish with 
healthy cells. In Mothersill's experiment, the healthy cells began to 
show effects of radiation and die.

Still, Morgan adds, "There are enough studies to show that this 
effect is real."

Mothersill says that she is now finishing up some other studies with 
the trout to identify the chemical signals that are passing between 
irradiated and healthy fish.
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Leo M. Lowe, Ph.D., P.Phys.