Unchecked industrial pollution coupled with peculiar geographical location has exposed the port city of Visakhapatnam to significant dosage of harmful radionuclides of uranium, thorium, radium and potassium

By Syed Akbar
Hyderabad: Unchecked industrial pollution coupled with peculiar
geographical location has exposed the port city of Visakhapatnam to
significant dosage of harmful radionuclides of uranium, thorium,
radium and potassium.

Though some of these radionuclides are present in higher quantities
than those found in other major coastal cities in the world,
scientists from the Bhabha Atomic Research Centre (BARC), Mumbai, play
it down saying they pose no radiological hazard. The concentration of
radium 226 in Visakhapatnam ranged between 11 and 57 Becquerel per
kilogram (Bq/Kg) as against the worldwide average of 25 Bq/Kg. Its
concentration in the Indian Ocean is 13.8 Bq/Kg while it ranged
between 13.9 and 25.2 Bq/Kg in the Bay of Bengal.

The Environmental Assessment Division of BARC collected about 10
samples of surface sediments from the sea in Visakhapatnam. It
analysed the samples for radioactivity levels including the annual
exposure to people. The study was aimed at establishing the baseline
data for the marine environment of Visakhapatnam, where BARC is
setting up a research nuclear reactor.

The current data will help nuclear scientists and environmentalists to
know whether the radiation exposure level has gone up once the test
reactor becomes operational. Incidentally, Visakhapatnam is also the
home to a nuclear submarine. A number of new industries are planned in
the city outskirts. Local of nuclear reactors and polluting industries
near water bodies increase the chances of contamination by many times.

The presence of radioactive material in the marine sediments in the
city is partly due to the geographical terrain. Industrial pollution
also contributed to the problem. The concentration of Uranium 238
ranged from 19 to 48 Bq/Kg, Thorium from 31 to 145 Bq/Kg and
radioactive Potassium from 363 to 1,024 Bq/Kg. “These values are in
general higher than the global averages,” the BARC team said in its
research study published in the Journal of Radioanalytical and Nuclear
Chemistry.

Visakhapatnam abounds in granitic rocks containing uranium, thorium
and radioactive potassium. The BARC team allayed the fears saying
radiological hazard is below the internationally accepted values.
However, the annual effective dose equivalent (AEDE) for Visakhapatnam
is between 0.1 and 0.2 mSv (millisievert) per year. This is more than
300 times higher than the global average of 70 microsievert per year.