Dear Dr. Zoomie – what is it about Mexico and all the stolen radioactive sources? Why is it happening there? And what sort of risk do these thefts pose?
Good questions! It sounds like you’ve heard about news reports concerning another stolen radioactive source in Mexico.
Let’s take them one at a time, along with a little background information.
We’ve talked about the security of radioactive materials in the past in this blog – there’s a certain level of security that the International Atomic Energy Agency (IAEA) recommends and that the Nuclear Regulatory Commission (NRC) requires. For the most dangerous sources, these security requirements are most stringent – if you have enough radioactivity in one place you’ll have to perform background checks (including fingerprinting) of anyone who will have unescorted access to these sources.
There are also transportation requirements – not only security, but also to move the materials safely. For example, high-activity sources are required to be secured in very strong containers (called Type B containers) that are marked with the radiation symbol and that are secured in the beds of trucks that must carry the radiation symbol. There are additional requirements, but these are the most relevant to your questions. So now let’s see what it is about Mexico that makes it the recent poster child for radioactive materials insecurity.
The biggest thing is that effective radiation safety regulation requires a strong and effective central government and a generally law-abiding society – Mexico has neither of these things at present. Organized crime – particularly the drug cartels – consumes so many of the government’s resources that there is little left to enforce compliance with radioactive materials regulations. Because of this, there is incentive for licensees to follow the rules – it’s easy to cut corners, reducing security for example, or neglecting to put the radiation symbol on vehicles or containers. This, in turn, means that thieves are unlikely to understand that the vehicle they are stealing is carrying radioactive materials. In addition, the general destabilization of the government and the general level of violence in society makes crimes (not just murder, but theft and hijacking as well) more common. So this answers the “why Mexico” part of your question.
Now we get to the risks, and let me look at both the risks to individual people as well as the risk to our society from these losses.
The risks to individuals from these sources can be substantial. The sources that were stolen in late 2013 contained over 2500 curies of cobalt-60 – this amount of radiation can give a person a fatal dose of radiation in just a few minutes at arms’ length from the sources, far lower-activity sources have caused deaths when the sources were found by unsuspecting members of the public. In fact, even sources with as little as 5 curies have given a fatal dose of radiation to people – a 5-Ci source of Co-60 can give a person a fatal dose of radiation in about two weeks or less, depending on the amount of exposure each day and the location of the source relative to the people exposed. Even the source stolen last week (some reports say it contains 120 Ci of activity) is a potentially dangerous source. Any individual would finds any such source needs to back away to a distance of at least 100 feet, contact the authorities (police, fire, or radiation regulators), and keep an eye on the source until help arrives. As long as you keep your distance – and NEVER try to recover or to shield a source yourself – you will be safe.
A somewhat larger question is the risk to our society, and the answer here is that we just don’t know. The three thefts in the last 15 months are troubling, but they seem to be accidental; the thieves seem to have stolen vehicles that just happened to hold radioactive materials – as opposed to stealing them because of the radioactive materials. This tells us that the thieves were most likely not terrorists attempting to construct dirty bombs, which is good. On the other hand, these thefts have given ample evidence that radioactive materials are poorly secured in Mexico – this might encourage the deliberate theft of radioactive materials from Mexico by groups who wish to cause us harm. So here we can only say that, to date, these thefts have been accidental and don’t seem to pose a risk to the US, but this might not always be the case.