Dangerous nuclear compounds were stolen from the back of an unlocked ute in the Melbourne suburb of Dandenong earlier this year, and remain at large despite a police investigation, according to the annual report of the Radiation Advisory Committee.
A senior research fellow in the Department of Biological Sciences at Macquarie University, Mr Janusz Gebiki, described the isotype contained in the stolen equipment, caesium-137, as “a highly dangerous emitter of penetrating gamma rays”.
Gebiki said there have been several injuries caused by exposure to lost, stolen or discarded caesium: “Because it is water soluble and behaves chemically like potassium, it is easily absorbed by organisms.” The biological half life was about 70 days, he said.
The ute belonged to an employee of a Melbourne environmental and engineering company, the name of which is being kept confidential by the committee. The committee could not say what the repercussions against the company would be.
The equipment was to be used on a job the next day, but was left in the ute, parked outside the employee’s home. Both the ute and the box in which the equipment was contained were unlocked. Dandenong police investigated the theft, and the Australian Federal Police and Australian Radiation Protection and Nuclear Safety Agency were advised.
The Secretary of the Radiation Advisory Committee, Julian Marwick, confirmed last week that the equipment had not been recovered. He said the material could be dangerous if handled incorrectly, but was not at the high end of risk: “I guess it’s all relative as to how it’s used… If it’s handled correctly it’s not terribly dangerous.”
Marwick said the committee had been in touch with all those licensed to have similar equipment to make sure it was locked and secure: “There are pretty strict requirements and we do conduct inspections.”
The theft is the most serious incident in the report, which includes another 33 cases where people were exposed to levels of radiation, most often as the result of medical error.
The committee also reported on research which had established “unequivocally” that ultraviolet tanning machines cause both skin and eye melanomas, and had been elevated to “top-most cancer risk category” by the International Agency for Research on Cancer.
Another issue considered by the committee was the use of security scanning in prisons, which could expose staff and prisoners to significant doses of radiation. So far as prisoners were concerned “there were benefits indicated in terms of detection of contraband materials that could result in harm to the person carrying them or others.” The committee recommended that dose meters be used to monitor the levels of exposure by staff.
All but one of the cases of medical exposure involved levels of radiation well below those that cause radiation sickness or increased risk of cancer. But in one case a cancer patient excreted radioactive “seeds” that had been implanted as part of his treatment. He picked them up and carried them in a plastic container in his trouser pocket.
He received a radiation dose double that which can cause increased cancer. When the patient brought the seeds back to the doctor, they were left for more than three days unshielded, and less than a metre from a desk used by medical staff, who would have been exposed to low doses as a result.
Another case involved the incorrect CT scanning of a patient because two people who both had the surname ‘Smith’ were confused with each other. Fortunately the dose of radiation received by the patient was low.
Also, a patient who had been previously diagnosed with breast cancer and received a full CT scan of bones, brain and pelvis was later discovered to be pregnant. The foetus received a low dose of radiation.
And a pregnant radiographer went in to a room where a CT scan was being performed to calm a patient. She has since claimed the scan was not properly paused while she was in the room, and as a result she was exposed.
The Radiation Advisory Committee is part of the Department of Health, and advises on radiation safety and risk. A copy of the report is claimed to be available online, but at the time of writing, the most recent report on the website was 2008.
Half life of Cs137 is 70 years, not days. Among fission products, it has a particularly long half life. This is convenient for shipping it around the world, as it doesn’t have to arrive there in a hurry. However it does mean that any spills or losses would take an unreasonably long time to die away. Hence the hoo-hah to get it back into captivity.
By the way, it is excess radiation that has to be controlled. Background radiation is part of our living environment wherever we are.
No wonder those of us who are aware of these ‘human errors’ aren’t in favour of Australia embracing nuclear power. I recall reading a book in the 70’s written by a Walter Patterson simply called ‘Nuclear Power’ (I think), and it was full of incidents and accidents. There’s been a few scares at Lucas Heights in recent years, and the then Minister in the Howard govt’s response was to castigate the Labor Party for even mentioning it – she took about 6 questions to even address the issue. Hardly a reassuring stance. Of course, I quickly add, that the Rudd/Gillard govts would’ve taken the same action.
I suppose we just hope that it hasn’t fallen into the hands of someone with evil intent, and doesn’t end up in a “dirty bomb”? Not very hopeful is it! I don’t feel reassured anyway! One would think that there’d be very strict guidelines for handling such matter – everyone knows about not leaving valuables in a car, don’t they?
The NSW govt recently announced, that it was going to send what was once “contaminated soil” to be permanently stored at Penrith. It had conveniently been renamed as “safe land fill”? Not only this, but a ‘PR firm’ had been employed to “reassure the public” of its safety? Of course, the people of the West were outraged, and rightly so. Somebody asked a very reasonable and rational question; ‘If it’s so bloody safe, why isn’t it being stored on the North Shore’? As I said, a prefectly reasonable question? The mind boggles! This soil was on a site that was a uranium facility decades ago. There’s been a history of cancers in the surrounding residential areas.
I’ve always maintained, that govts, property owners of nuclear facilities etc, can’t be trusted with our health and safety when it comes to these issues – nor would the police or army or private security people – all have a vested interest in telling lies and other forms of cover up. There’s been a history of lies and bs over many decades in many countries – the US/Britain being repeat offenders!
I suggest, that if the said “soil” is so safe, the pollies should divvy it up and take it home to add to their veggie gardens – some nice tomatoes would be a good idea? (beat the anticipated price rise in the coming months?) Little Tiny Toms? or whatever, that could ‘glow in the dark’ would look cute I reckon!
any irradiated drug addicts turning up at emergency departments recently?
Umm, Roger, I think its radioactivity half life is 30 years? (which effectively is no different). The report talked about biological half life of 70 days, which probably means its dwell time in the body before being excreted? (I should know, having done my PhD on radiobiology a lifetime ago but the half life of my memory feels like about 70 days too!)
It is pretty disturbing that the workers treated this with such casual indifference. It is used in machines to deliver precise dosages of gamma radiation, mostly in research settings. (Possibly it is also used to sterilize surgical instruments?) Almost every university campus will have at least one such machine–essentially a massive large-fridge size block with an elevator shaft that takes things to be irradiated up and down to the radiation source. I believe there is only one source of this kind of “medical” caesium, Canada’s Chalk River nuclear research facility; which I only bring up because it allows me to tell the irrelevant story of how, as a student, I once walked into Chalk River labs several miles through shoulder-high snow, from the highway where the Greyhound dropped me!
Anyway, the Cs is likely to be pelletized and coated so that it doesn’t represent an environmental hazard (not going to get into the food chain or the water). And it would have been stored in a large lead cannister. So the main risk is that the thief sells the lead and just discards the pellets. All of this would have those big red radiation danger symbols all over it, and the massive lead cannister would give anyone a clue that maybe it shouldn’t be messed with–but of course there are Homer Simpson types out there. If it gets buried in landfill it is most likely perfectly ok. But if left lying around in a garage or whatever anyone staying very close is going to get a dose and maybe a burn; but of course that does not show up for days after exposure so they may not associate the burn with its cause.
Cs-137 is the main long-lived nasty from nuclear bombs and is still the main problem in Chernobyl.
Hmm, might be a bit more dangerous due to its chemical reactivity, just found this on Wiki:
“The improper handling of caesium-137 gamma ray sources can lead to release of this radio-isotope and radiation injuries. Perhaps the best-known case is the Goiânia accident, in which an improperly-disposed-of radiation therapy system from an abandoned clinic in the city of Goiânia, Brazil, was scavenged from a junkyard, and the glowing caesium salt sold to curious, uneducated buyers. This lead to multiple serious injuries from radiation exposure.”
and:
“Caesium gamma-ray sources that have been encased in metallic housings can be mixed-in with scrap metal on its way to smelters, resulting in production of steel contaminated with radioactivity.[7] One notable example was the Acerinox accident of 1998, when the Spanish recycling company Acerinox accidentally melted down a mass of radioactive cesium-137 that came from a gamma-ray generator.”
Just for the record, so I don’t mislead people, it is Cobalt-60 that is more commonly used in those radiation-delivery machines and surgical sterilizers, and therapeutic radiation delivery. It is less chemically reactive than Cs and has halflife of about 5 years.
Chalk River was in the news in 2007 because it had to close (and again in 2009) for an extended period. This caused alarm around the world because Chalk River is the major supplier of these medical isotopes and risked impacting on cancer therapy throughout the world. There are only 4 such producers in the world and they are all over 40 years old (the reason why they are having increasing unscheduled closures.)
So Liz, also be aware that these isotopes have a hugely beneficial medical and research use. Diagnostics as well as therapy. No reason not to take great care in their handling but also we shouldn’t be alarmist about research reactors like Lucas Heights.