Amidst fears that militant groups are looking to seize radioactive materials to use in a terror attack, reports now suggest that a containment of the highly radioactive and dangerous substance caesium-137 has disappeared in Kazakhstan.

Local police in the Mangistau region said that the container may have fallen from a transporter and is now missing.

"The container with the radioactive isotope caesium-137 has not been found so far," local source Azamat Sarsenbayev told the AFP news agency. Details surrounding the incident are sketchy but it appears that the consignment has actually been missing since last Wednesday.

Exposure to caesium-137 is extremely dangerous, usually resulting in severe burns or death; consequently, a rigorous search for the whereabouts of the missing container is now being conducted by security services, emergency response workers and the military. Around 50-60kg of the radioactive substance, which has a half-life of 30 years, is believed to have gone missing, though it is not clear where it originated from. Caesium-137, along with other radioactive substances such as cobalt-60, iridium-192 and americium-241, is used in a variety of applications within hospitals, universities and industry worldwide, including smoke detectors and cancer therapies.

Analysts believe the radioactive material was lost as it was being transported via truck across the western part of the country. Tom Bielefeld, a German-based physicist and nuclear security analyst believes that it is likely to have originally been used in the oil industry in equipment that measures the depth of oil wells. Another possibility is that it was derived from Kazakhstan’s decommissioned BN-350 nuclear reactor.

Regardless of their origins, losses or thefts of these substances must be reported to The International Atomic Energy Agency (IAEA), the UN atomic watchdog; however, the IAEA has yet to comment on this latest disappearance.

The most pressing fear is that the nuclear materials could be utilised to construct a "dirty bomb" – a crude device that uses conventional explosives to disperse radioactive materials. With nuclear materials being used in a growing number of applications across the globe, there is an increasing potential for them to fall into the hands of criminals and radical groups.

“There’s concern that these sources are widely spread and easily accessible,” said Andrew Bieniawski, vice president of material security and minimization at the Nuclear Threat Initiative and a former top official in the U.S. National Nuclear Security Administration.

“They’re used in everything from oil wells to the medical industry. You have thousands of these sources around the world, and people don’t realize they’re a threat.”

The IAEA confirmed that about 140 cases of missing or unauthorized uses of nuclear and radioactive materials in 2013, but many losses and thefts go unreported, explained Bruce Bennett, a defense analyst at the Rand Corp. Incidents occurred everywhere from Uzbekistan to the United States, and security surrounding the radioactive substances is often lax, particularly in less well-developed countries.
“I don’t think we have a full accounting of everything worldwide,” said Bennett. “Dentists don’t have armed guards patrolling their X-ray machines, and if a dentist’s office gets raided, it may not even make the news.”

Thefts of radioactive substances hit the headlines earlier this year when incidents occurred in Mexico, and also in an area of Iraq that is currently controlled by the terrorist group The Islamic State of Iraq and the Levant (known as ISIS or ISIL).

“A big, nasty terrorist organization in control of swaths of land including science labs and such — that’s scary,” said Matthew Bunn, a professor at Harvard University’s Belfar Center for Science and International Affairs.

Bunn explained that a bomb constructed by those without expert knowledge may not result in a high death toll but could disseminate radioactive particles far and wide, causing substantial socio-economic damage and long-term health risks.

“Most of the danger comes from the economic cost and from need to disrupt an area and evacuate people,” he said. “But educating people on the risks of radiation is very hard. People don’t pay attention until something happens.”

“The U.S. and [President Barack] Obama were trying to take the lead in securing nuclear material around the world, yet we’re completely failing to take part in the legal instruments necessary for nuclear security," warned Bunn." That’s really an embarrassment.”

Leaders from 53 countries – including U.S. President Barack Obama – are calling for more international action to help prevent radical groups from obtaining atomic bombs.

At a meeting in The Hague on March 24-25, they will say that much headway has been made in reducing the risk of nuclear terrorism but also make clear that more must be done to ensure that dangerous substances don’t fall into the wrong hands.