US Begins First Human Trial of Dirty-Bomb Antidote

What is a dirty bomb?

Also known as a radiological dispersal device or RDD, a dirty bomb is an explosive that has been mixed with radioactive material so that when it goes off there will be contamination of the blast zone.

A dirty bomb is not a nuclear bomb - it is "weapon of mass disruption" rather than "mass destruction", says the US Nuclear Regulatory Commission.

The cloud of radiation from a dirty bomb could be dispersed within a few blocks or miles of the explosion, whereas a nuclear bomb could spread thousands of square miles.

Exposure to radiation can damage a person's DNA, tissues and organs, leading to illnesses, including cancer, which is why an oral drug that could counteract some of the effects would be useful.

There are already two different drug injections that can be used to treat people who have been exposed to radioactive plutonium, americium or curium.

For decades, experts have also known that iodine tablets can be deployed to help protect people if radioactive iodine has been released into the environment; it was given to people in 1986 when a nuclear accident occurred at the Chernobyl power plant.

Another pill, Prussian blue (potassium ferric hexacyanoferrate), can help remove radioactive caesium and thallium.

If HOPO 14-1 works, it would be another to add to the stockpile, offering protection against uranium and neptunium in addition to plutonium, americium and curium.Dirty bombs are different from nuclear ones as they can only contaminate an area of a few miles from the explosion, as opposed to a thousand.

Two drugs, both made with diethylenetriamine pentaacetate (DTPA), are already used on people exposed to radiation.

Iodine tablets have also been administered to people exposed to radioactive iodine from a nuclear accident, such as the one at Chernobyl in 1986.

But if proved to be safe and effective, HOPO 14-1 could be given to people in tablet form, which would be much easier than intravenous methods in the event of an emergency.

It would also offer an antidote to more dangerous elements than just iodine, including plutonium, americium and curium. The first phase of the trial is being funded by the US National Institute of Allergy and Infectious Diseases (NIAID) and conducted by the research institute SRI International in California.

It will be carried out on 42 healthy adults, aged 18 to 65, who will be given varying doses of the drug.

They will be monitored for 14 days, with results expected in 2024.

Weapons of mass disruption

Dirty bombs, also known as radiological devices or RDDs, are classed as "weapons of mass disruption" by US authorities.

They cause far less damage than nuclear bombs, or "weapons of mass destruction". But if inhaled, ingested or exposed to an open wound, the substances they emit can cause cancer, DNA and organ damage.

No dirty bomb attacks have been successful.

Chechnya rebels planted a bomb containing dynamite and radioactive caesium-137 in Izmailovo Park in Moscow in 1996 but it was found and destroyed. Two years later, the Chechnyan intelligence service defused a dirty bomb left near a train line.

Al-Qaeda operatives have also been arrested for dirty bomb plots in the UK and US.

During its invasion of Ukraine, Russia has claimed that Ukrainian forces plan to dirty bomb its own citizens, but this has been dismissed as "transparently false" by the West. The drug, HOPO 14-1, is thought to work against several materials that might be used in weapons, including uranium.

If it proves safe and effective it could guard against potential harm from nuclear accidents or terrorist attacks.

About 42 volunteers will try different doses, checking for side effects.

There will be "intensive safety monitoring", with results from the phase one study expected in 2024, say the trial leaders from SRI International of Menlo Park, California, who are receiving funding from US government agency the National Institutes of Health.

There has not yet been a successful dirty-bomb attack anywhere in the world.

However, there have been attempts.

In 1996, rebels from Chechnya planted a bomb containing dynamite and radioactive caesium-137 in Moscow's Izmailovo Park.

Security services discovered its location and it was defused.

In 1998, Chechnya's intelligence service found and defused a dirty bomb that had been placed near a railway line in Chechnya. If it proves safe and effective it could guard against potential harm from nuclear accidents or terrorist attacks.

About 42 volunteers will try different doses, checking for side effects. There will be “intensive safety monitoring”, with results from the phase one study expected in 2024, say the trial leaders from SRI International of Menlo Park, California, who are receiving funding from US government agency the National Institutes of Health. Also known as a radiological dispersal device or RDD, a dirty bomb is an explosive that has been mixed with radioactive material so that when it goes off there will be contamination of the blast zone.

A dirty bomb is not a nuclear bomb – it is “weapon of mass disruption” rather than “mass destruction”, says the US Nuclear Regulatory Commission.

The cloud of radiation from a dirty bomb could be dispersed within a few blocks or miles of the explosion, whereas a nuclear bomb could spread thousands of square miles.

Exposure to radiation can damage a person’s DNA, tissues and organs, leading to illnesses, including cancer, which is why an oral drug that could counteract some of the effects would be useful.

There are already two different drug injections that can be used to treat people who have been exposed to radioactive plutonium, americium or curium. For decades, experts have also known that iodine tablets can be deployed to help protect people if radioactive iodine has been released into the environment; it was given to people in 1986 when a nuclear accident occurred at the Chernobyl power plant.

Another pill, Prussian blue (potassium ferric hexacyanoferrate), can help remove radioactive caesium and thallium.

If HOPO 14-1 works, it would be another to add to the stockpile, offering protection against uranium and neptunium in addition to plutonium, americium and curium.

There has not yet been a successful dirty-bomb attack anywhere in the world.

However, there have been attempts.