Scientists from the Bhaba Atomic Research Centre (BARC) and Narora Atomic Power Station also scanned Mayapuri Industrial area this morning to examine whether there was any other source of a similar emission in the vicinity.
Panic was triggered in the locality last night after the news of a radiation leak broke out with five persons falling ill after coming in contact with a "mysterious shining object" in a scrap shop.
"The experts have identified the material as Cobalt-60. They have identified six sources of Cobalt-60 from the scrap shop," B B Bhattacharya, member of National Disaster Management Authority and former Director of BARC, said.
Cobalt-60 is a radioactive isotope of cobalt, which is a hard, lustrous, grey metal. Cobalt-based colours and pigments have been used since ancient times for jewellery and paints, and miners have long used the name kobold ore for some minerals.
Bhattacharjee said Cobalt-60 is used in fabrication work, specially for welding steel. It is also used in radiotherapy for treating cancer.
The experts, who first collected and isolated the mysterious shining object from the scrap shop in Mayapuri Industrial area in a sophisticated lid, had sent it for further investigations.
According to Deputy Commissioner of Police (West) Sharad Aggarwal, experts visited the Mayapuri scrap market this morning also and scanned the area to check whether there was any other source of radiation emission in the vicinity.
"The team had identified the source of radiation. They have collected the material and isolated it. They are examining it," Aggarwal said.
Bhattacharjee said the radiation was from a "very powerful source" as Deepak Jain, the scrap dealer undergoing treatment in Apollo Hospital, is in a serious condition.
After the news came to light last night, police cordoned off the area upto one km and did not allow people to enter the locality. There are around 200 scrap shops in the market.
Scientists from the Crisis Management Group of Department of Atomic Energy (DAE) and Atomic Energy Regulation Board had last night carried out the survey of the extent of radiation in the area.
The incident came to light yesterday when Jain, the scrap dealer who suffered serious burn injuries, was yesterday rushed to Apollo Hospital which informed the government that he had suffered radiation, officials said.
Jain fell unconscious and his hands had turned black after coming into contact with the object, part of medical waste which was bought from a city hospital. Four workers employed by him also suffered injuries in the incident.
Soon after the radiation, safety officer of Apollo Hospital informed the authorities that Jain has been exposed to radiation. A team from NDMA's Emergency Response Centre then rushed to the spot in the afternoon.
They were joined by a six member team, including a doctor, from BARC later last evening besides ten scientists from Narora Atomic Power Plant.
According to a senior official, the radioactive substances were put in an almirah by the scrap dealer who was unaware of its radio-activity.
Bhattacharya said they were looking for more sources of radiation in the market. "It is a very congested area. We feel that more people were exposed to radiation as the material was there for about a week," he said.
"We have asked the authorities to properly examine the locality as well as people in the area," Bhattacharya said.
Asked how the material made it to scrap, he said, the scrap dealers do not have requisite instruments to check whether any material they collect is radioactive or not.
"We do not know the source from where it came from. Whether it came from abroad or not, we do not know. Hopefully, we will be able to ascertain the facts soon," he said.
"We are yet to get details. We do not know whether the operator hid the source. Such material sometimes come to the public domain," he said.
Jain's relative Rajesh said that there were small black patches on the scrap dealer's body and they kept getting worse. Locals said there was a peculiar smell in the area.
Ajay, a resident of Mayapuri said, the scrap was brought to the shop about a week ago.
"They were cleaning the object when one of the labourers started losing hair. His finger nails also broke. Others also then fell ill," Ajay said.
Though police suspect that the dealer bought the material from a city hospital, they are also investigating reports whether he got it from Faridabad.
"We are also probing whether the scrap material originated from abroad," a senior police official said.