Bioaccumulation of radionuclides: Kudankulam nuclear power plant is safe

By Syed Akbar
Hyderabad: The proposed Kudankulam nuclear power plant will
not affect the marine animals and human beings, who consume them.

Zoologists, who conducted studies on naturally occurring and man-made
radionuclides in the south Bay of Bengal for over five years, have now
concluded that the nuclear power plant at Kudankulam village will not
alter the marine ecology. It will also not influence the
bioaccumulation of radionuclides in sea animals including commercial
fish and molluscs.

The sea animals present near the site already contain natural radionuclides through bioaccumulation, and thus the radionuclides even if released from the Kudankulam plant cannot compete with and replace the natural ones.

Researchers from the department of advanced zoology and biotechnology,
Sadakathullah Appa College, Tirunelveli, and the department of zoology
and research centre, Scott Christian College, Nagercoil, conducted the
study on the radioisotopes of lead (Pb210) and polonium (Po210) in
marine waters, commercial fish and other sea animals in and around the
Kudankulam region.

“We selected the radioisotopes of lead and polonium because they are
the two most dominant contributors to radiation dose both in animals
and human beings through seafood intake. The bioaccumulation in marine
plants and animals was found to be within the permitted range fixed by
international agencies like IAEA and ICRP,” Dr M Feroz Khan of
Sadakathullah Appa College told this correspondent.

He clarified that even if there is a release of radionuclides into the
marine environment, the continuous dilution process will make the
levels low. The fallout (man-made) radionuclides cannot compete with
and replace the natural ones already bioaccumulated in the
animal/plant tissues.

“A comparative study of fallout cesium and natural polonium in fishes and their dose to human beings shows that there is a huge difference in the  bioccumulation of both radionuclides. There is no harmful impact now and there cannot be any in the future,” Dr Feroz pointed out.

The researchers also calculated the effective dose and carcinogenic
risk to humans consuming these species, but found that the “estimated
risk exerted no significant health hazard to humans.” The marine
organisms can also considered safe within international guidelines.

“Our study revealed that natural radiation level is higher, whereas
the fallout (human sources) radiation level is markedly less than
values reported internationally. Our data would be a baseline
pre-operational input, fulfilling the radio-ecological database and
will also be useful in the future impact assessment of the Kudankulam
nuclear power project after it becomes operational,” Dr Feroz added.