CBRN / HazMat Training Blog

Litvinenko and the perfect radioactive poison: polonium-210

Written by Steven Pike

Radioactive material

 

Fifteen years ago, on November 1, 2006, Alexander Litvinenko was poisoned in London’s Millennium Hotel. The murder weapon, disguised in a pot of tea, was polonium-210: an undetectable, tiny, rare radioactive isotope. By the time he had taken the first sip, his demise was already a fait accompli. 

Alexander Litvinenko’s death by poisoning 

Alexander Litvinenko is the unlikely recipient of the Guinness World Record for being the first-ever person murdered by radiation. But he never found out what had killed him—it took until six hours before his death for the lab at the Atomic Weapons Establishment to confirm he was contaminated with radioactive polonium. By this time, he was in an induced coma and never again regained consciousness.

Polonium-210 had presumably been chosen as the murder weapon because those responsible believed it would never be detected. And they were almost right. Doctors were initially perplexed about the reason for Litvinenko’s sickness. They eventually decided upon a diagnosis of thallium poisoning—but remained unconvinced. Although some of his symptoms fit with thallium, he did not suffer from peripheral neuropathy, leading doctors to eventually discard the diagnosis. 

The correct detection of poisoning with radioactive polonium was only made after a collaboration involving a group of medical doctors, SO15 detectives, a scientist from the Atomic Weapons Establishment, and a scientist from Porton Down (home to the Ministry of Defence’s Defence Science and Technology Laboratory). The team tested a large urine sample and established the presence of a radioactive isotope.

Subsequent forensic examinations also found polonium-210 in the Millenium Hotel. There were 2,600 counts per second in a toilet cubicle and over 5,000 counts per second on a hand dryer. “Counts per second” is used to measure rates of ionising radiation; to put this measurement in perspective, anything above 150 counts per minute means the substance is dangerously radioactive. The reading in the hotel was off the scale.

What is polonium-210?

Polonium-210 (also known as Po-210, (210)Po, or 210 Po) is a radioactive chemical element (atomic number 84) that was discovered in 1898 by Marie Curie and named after her native Poland.

It is one of the most toxic substances known; the danger comes from when it emits radiation. It is estimated that one gram of polonium-210 is enough to kill 50 million people and sicken another 50 million.

Litvinenko ingested less than a millionth of a gram.

It is one of several radioactive poisons that could have been used as a lethal weapon whilst causing the murderer no harm. If stored in a glass bottle, the radiation cannot pass through the walls— a thin piece of paper is enough to block the radiation. It is not even able to pass through skin. 

To prove fatal, polonium-210 must enter the human body via an open wound, be directly inhaled—or ingested. Once inside, it can travel around with ease; the element’s particles deposit huge amounts of energy in the form of highly energetic alpha particles. It becomes concentrated in red blood cells and then spreads through organs and tissue to the liver, kidneys, bone marrow, and gastrointestinal tract. Damage to DNA from the alpha particle radiation causes apoptosis, a type of cell death, and the body ceases to function.

Polonium-210: the perfect poison?

In addition to being lethal, polonium is the perfect poison for another reason: the fact it is so hard to detect. Doctors such as the ones caring for Litvinenko in University College Hospital, London, often can mistake it for simpler poisons, which could derail an investigation.   

An additional reason to consider polonium-210 the perfect poison is that it can be concealed and transported across borders with ease. Standard radiative materials set off radiation detectors, but polonium-210 does not. So anyone transporting the element can do so without fear of discovery.

Transportation is made even easier as the material can be carried in crystallised or powdered form or diluted in a bottle of liquid. Identifying it as polonium-210 requires a highly-trained lab technician and advanced equipment—both of which are not readily available. 

Emergency responses to radioactive sources

Murder using radioactive poison is rare (so rare it has only happened once). But there is still cause for concern as, globally, over the past 25 years, there have been around 3500 incidents. Every year, there is an average of one serious radiation incident. Three hundred and fifty of these involved stolen or misused radioactive sources, including the infamous radiological event in Lilo, Georgia, where sealed radiation sources were abandoned and no safety procedures were followed. Consequently, eleven border guards were exposed to radioactive sources for prolonged periods of time.

Following the correct procedures to store and transport radioactive materials is paramount; however, systems are not fallible, and the sheer number of historical incidents show us that it is important to be aware of how hazardous radioactive materials are. 

The first hurdle is to correctly identify a material as radioactive. Whilst this is relatively easy to do if containers are correctly labelled using the trefoil symbol, the problem arises when there is no indication of the type of materials that are being stored. 

There are, however, some indicators. Sealed radioactive sources are usually stored in heavy metal containers with shielding made of lead, tungsten, or depleted uranium, which shield the uranium. Any container that is abnormally dense and heavy must be treated with caution as this is a potential indication that it is being used to shield a radioactive source.

Identifying radioactive materials

Radioactive materials must be identified and recovered as promptly as possible. If the area in which the materials are located is already known, physical and administrative searches can be carried out, but radioactive sites are often undocumented. 

According to the Nuclear Threat Initiative

There are new and innovative methods “such as network analysis, online surveys, and open-source searches utilizing new tools, such as geospatial analysis, aerial images, social media, as well as YouTube videos, can be used to enhance the national regulators’ ability to track down and secure orphan or abandoned radioactive sources and prevent them from potentially falling into the hands of terrorists or other nefarious actors.”

These novel methods are excellent ways of helping investigators reduce the size of the area that needs to be surveyed. When in the field, investigative teams will need to use detection devices to positively identify and address radiological materials. 

The benefits of simulation training for investigators

Using simulation as a training tool is a widely used method of preparing investigators in the field to correctly identify radioactive materials. 

Argon Electronics has over 30 years of experience as a global provider of Chemical, Biological, Radiological and Nuclear (CBRN) detector simulators. We have developed strong relationships with many of the leading detector manufacturers, which allows us to create realistic simulators that are almost identical to the real devices.

This allows instructors to create realistic scenarios and train future investigators who will accurately be able to detect radiological threats before they further damage human and environmental life.Radiation Case Study

Steven Pike

Written by Steven Pike