M A I N   N E W S

A Tribune Exclusive
Strength of Cobalt-60 sources alarming
Highest radioactive source strength ever found in public domain in India
Aditi Tandon/TNS

New Delhi, April 15
In a development that should bother radioactive waste regulators in India, scientists working on the nature of Cobalt-60 sources detected in the capital over the last week have found the strength of these sources to be unacceptably high and dangerous for human health.

Experts from the Bhabha Atomic Research Centre (BARC), who isolated eight Cobalt-60 sources from West Delhi’s Mayapuri area (the latest three isolations happening over the last two days) today put the maximum detected strength of the isolated radioactive sources at a whopping 1000 Roentgen (R) per hour.

This is the highest radiation field of any radioactive source ever detected by scientists in public domain in India. It is enough to cause lethal damages to those affected, including genetic damages.

The minimum radiation field of the isolated Cobalt-60 sources has been estimated at 20 R per hour while that of the radioactive source detected last night in Mayapuri area has again been found to be a high of 500 R per hour.

Roentgen (R) is the special unit of radiation exposure, which helps measure the ionization produced in the air by X or Gamma radiation. A dose of about 500 R in five hours is considered lethal for humans. A typical dose of normal background radiation for a human is just 200 mR (micro Roentgen) per year.

Admitting that the radioactive source strength of 1000 R per hour is extremely dangerous and unacceptable for public domains, Dr SK Malhotra of the BARC today told The Tribune that the only saving grace had been that the said sources were mostly buried under scrap and, therefore, were not as dangerous for the affected persons as could otherwise have been. Scrap shop owner was the most severely affected as he kept the source in a nearby box.

“We define a radioactive source not by weight but by its radiation field which is measured in Roentgens. The radiation fields of the Cobalt-60 sources under investigation range between 1000 R per hour and 20 R per hour. 1000 R per hour is exceptionally high source strength. We have encountered it for the first time in public domain,” he said.

Meanwhile, five persons affected by radiation in Mayapuri continue to be critical.