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hello and welcome to technically speaking where scientists and Engineers come together to chat about a common interest share knowledge and satisfy some curiosity I'm Antonia and I'm joined by Laura to talk about radiation and whether films portray accurately so Laura you used to work with radiation and you also had some thought based on a film you watched recently I did yeah so I used to work in a lab that had two different sources of radiation and I've worked in the nuclear industry for quite
a while so I'm fairly familiar with radiation protection procedures but uh probably Last Christmas I was watching Batman Dark Knight right near the start they mentioned the use of irradiated bills and I thought huh so it made me think about how it's portrayed and what those words mean yes and I don't remember that I did watch the film but that didn't stick in my memory so what do you think think they were on about sounded like it was a way of tracing where money had ended up because they
were trying to track down some criminals essentially and figure out how they were selling drugs where they were selling drugs that sort of thing and gathering information on them so I think when they say irradiated it was a way of tracing the bills using radiation it's not quite what the word irradiated means though I'm imagining glowing green American dollar s now that would in a way make more sense than the way they were using it in the film yeah if something wasn't radiated
what would that actually be that would literally mean you'd be exposing something to radiation right which I used to do all the time us bills are made of a combination of linen and cotton I think so if you were to expose that to radiation You' probably find that it would just end up being a bit discolored and maybe a bit brittle I used to irradiate paper all the time time it was a good way of marking my samples and that would definitely come out looking very aged so I guess it
would do the same to the builds so once the paper is radiated would it give off any radiation it's unlikely it would depend on what you radiated it with so I tended to use gamma radiation which is photons it's similar to light it's just higher energy if you were to radiate something with neutrons they can make something radioactive if they get absorbed by the atoms they'd go into the nucleus and then they would change whatever atom into a different isotope which may be unstable therefore May
undergo radioactive decay but I'm also not sure that's what Batman did well I'm also just thinking just because they blasted swing with radiation doesn't mean it then gives off radiation which you could then actually detect and follow someone with instead you just have discolored paper bills yeah which I guess you could detect using certain means like spectroscopy but I don't I think that's what Batman was doing when he held his little detector device that had a radiation
Hazard symbol on it I assume he was using it like could use a g counter I may have read far too much into this and overanalyzed it a bit too much yeah and is it possible that it would be above the background radiation because then how much would it have to be for it to stand out against the buildings which have background radiation from Stone it would depend on how you'd calibrated your sensor so say he' picked a particular I isotope to smear across these bills and then fixed it to the
bills in some way so people couldn't then become contaminated with it that isotope will give off radiation with a particular energy so we could have calibrated a sensor to look at just that and it could be something that's not so common so that's one way you could do it and it can be quite sensitive when you do it that way uh I would expect it's not really exactly what I did in my field of work but I can definitely see how that' be possible if this is a thing
you would ever do in real life anyway yeah but it it gives us a bit of a thought experiment of could we be using radiation to track things in the way like a GPS pings out a signal and then you pick up that signal but it has to also be you have to have a detector so what kind of guy counter could you have that could follow it presumably through streets of Gotham City on that kind of scale oh could you get anything that was that I guess you could get something
that was that sensitive I'm not too sure how you do the logistics of it so there is a way of detecting how nuclear reactors are operating from quite a long way away and I can't remember any of the details of it I think it's something to do with neutrinos but I might be misremembering that and that sort of thing is very sensitive from like kilometers away wow but it's also very specific to a particular application whether it would work with something that's been irradiated or is carrying a
radioactive isotope versus something that is undergoing fishing and giving off a lot of energy I don't know H I'm also imagining is that going to be a big dish to pick up that is the bat symbol also where he's got his radioactive detector to then have some other Communications to his little handheld device that presumably telling him where everyone's going maybe maybe you could use something with uh scintillation counters I guess that can be quite sensitive you'd still have to calibrate
it though and that's the tricky bit because you rightly said you want to detect things that are outside of normal background radiation that's probably not so easy to do I think you do need to do it Case by case if Batman knew what radio isotope he's used he presumably would also know the energies so he could have it calibrated so it's kind of paintball he's made that paintball he knows how to use it yeah he could do and when I looked at what he was doing in the film he was holding his detector
really close I thought well that's probably Alpha radiation in that case told you I thought about this way too much so you could use something like ponum 210 it's got quite a long half life as well so it gives off radiation for quite a long time on alpha particles quite easy to absorb as well so if it got covered up surely it would then be absorbed and then you've lost your sort of signal it would yes so the advantage is that because Alpha radiation is blocked by your skin you're unlikely to
receive any sort of radiation damage from it but he would have to hold his detector quite close to it which is what he was doing in the film that seemed to be his method of detection he had to be in the room with with the bills I'm very skeptical of this yeah I did a quick Google search I don't going to get anything specific about how they actually Trace bills but apparently you just use some sort of die that flues under UV and a really efficient money counting device that can
go through lots of bills really quickly and can see that die that's apparently quite a standard way and sounds much more feasible unsurprisingly yeah but it doesn't exactly tell you live information it's not like a GPS track you would just know where they've spent the money you would and if you can correlate where where they've been yeah I get the impression from bit of research that I did that lots of businesses may have money counting devices that can detect these sorts of
things potentially or there's some sort of government police coordination to figure out these things they normally do it in coordinated way right similar to the way Batman was doing with Commissioner Gordon they'd know there might be some criminal activity here so focus on this area and we'll send out some bills that we can trace so that a bit of it I suppose made sense okay from the little I know about how money tracing Works who knew that this this is where your background and radiation
would take you this is what happens when you just overanalyze films though and you think oh come on you're not really representing that Faithfully surely no one would use radiation to track bills because they are safer methods of doing it you wouldn't expose people to an unnecessary dose even if it were tiny yeah yeah no there are there are literally guidelines about that yeah but we have we have heard of using radio isotopes for actually tracing things but just in different applications yeah so
one of the first instances I heard about this was ah nearly two decades ago when I was a relatively fresh graduate in the nuclear industry um it's sounds like it's actually quite a common method used in non-nuclear settings to trace things so you're basically looking at a radiation signal passing through something we were using it to measure the level in a vessel where we didn't have any other radiation sources around basically you calibrate a sensor on the
other side of this vessel for the amount of radiation when the vessel's empty and as the signal drops off you can figure out how full the vessel is so it's a non-invasive way of knowing what your fill level is essentially ah I was going to say there are much more basic ways of checking the level in something such as opening the top yes there are so yeah now you're saying non-invasive makes a little more sense to do that yeah I guess it would be for Industries where
you wouldn't necessarily want to open the lid and stick your face in and have a look as it as chemicals yeah there are I can think of a few where it where it's like that or it's it's just not feasible tanks can be very big and to climb all the way up to the top you've got to have a permit to work at height got to have a permit to open it and then got a permit to not fall into it yeah I'm thinking of more B my ES scenarios that would lead to super villains now from falling into
tanks but how funny that you're using radiation is a safer mechanism than just going and having a look this is the challenge of explaining industry and scaling up things I think this is a classic chemical Engineers problem of it makes sense in a lab but it doesn't make sense when you have a whole production site based around this so talking about scaling things up there are some quite good examples of tracing things on a huge almost like a Geographic scale all
right so there's an example dating back from probably about 40 years ago now of uh leak testing at 140 km of crude oil pipeline in India and they were accurate to one meter using uh Broman 82 which is a gamma emitter they could detect the gamma from whatever distance away through whatever medium it had to pass through I didn't see any details on where that pipeline was presumably underground or under sea but that is one very large engineering scale especially
if you don't have V you know pipe work is often hidden away we don't like to see it um and also you get a bit more protection if it's not exposed so yeah finding a leak would be quite hard until it resurfaces yeah and if it's something that's similar to the medium that you're already in anyway or it's really dilute how would you know there's also examples of seeing how things disperse in the environment as well um so things like measuring water discharges to rivers and
canals you can use technum 999 to do that it's another gamar emitter it's a quite short half life as well so you can get quite good time resolution if you wanted to I also heard about using radio isotopes almost as a marker so you know how far it's been sort of absorbed into the environment as well because you could see if there's particular places where it's popped up more yeah so to see if like a particular substance concentrates somewhere and then try and
figure out why that might be is that the example that you saw it was specific to fertilizer so seeing the uptake of nitrogen and they had nitrogen 15 so they can spot it I think there are probably lots of examples like that and you don't tend to hear about them all that much but they're definitely there and I wonder if part of the reason you don't hear much about it is because people think that it will be sort of scary to think about the idea that crops or whatever else are absorbing
radioactive material but they do that anyway radioactivity in the environment Brazil nuts are a good example of this cuz those trees have a really big root structure that extends really far they suck up a lot of pottassium so they end up sort of concentrating it and there are naturally occurring radioactive isotopes of potassium I've heard that of bananas as well so some people say how much is an equivalent dose in bananas I have heard that's quite a common one yeah another place where
we've heard about radioactivity is in medicine it's used in a variety of ways isn't it you can either use it to trace where things have gone in the body or you can use the radiation to treat certain conditions like certain cancers or thyroid problems um and they normally attach it to some molecule that tends to go to a particular part of the body so they could potentially use the same radioactive isotope for all of this and just add some chemistry to it but it's
carefully chosen so they understand how much radiation dose you're getting so it would be gamma radiation that we're using in order to be able to to detect outside the body otherwise you know Alpha is just going to be ionizing the internals of the person who's trying to you're trying to treat and would be to make it out of the body either it would depend where it was but probably not and you want the radiation to leave the body right because if it comes to the end of
its track in the body it will probably do more damage it's a weighted risk isn't it you've kind of measured how useful it would be yeah and I think we've sort of briefly gone over quite a lot of uses of radiation in engineering and in the body as a tracer and various other things not so much for money though yeah going back to sort of how radiation is portrayed in films you often do see that Hazard symbol of radiation warning and it kind of gives off a bit of a scary fearsome impression
of a radioactive area I imagine that isn't how you'd see it since you've worked with it no that's a good point I tend to think the same thing when I watch films they they treat it like it's some really bad thing and it's just something else to be understood and worked with it's similar you know working with electricity where you tend to get trained people to work with it or crossing the road you tend to be more cautious when you're about to cross a really busy road right and you there are
actual procedures that you follow at to Cross Road stop look and listen so thinking of procedures in Star Trek sometimes before they go into high radiation area they use what they call a high hpos spray to give them protection against radiation or they take pills do you think there is such a thing that exists in the world um it would depend on the environment that you're going to go into the radiation dose and potentially the Isotopes that you're exposed to for example iodine is taken
up by the thyroid and it concentrates there so sometimes you might be given iodine tablets to take if there might be quite a lot of radioactive iodine in an environment the idea is that the pills would contain non-radioactive iodine and that would go to the thyroid and then that would mean there wouldn't effectively be enough space for radioactive iodine to accumulate there that's how I understand of it anyway so that's a very specific radioisotope yeah and that tends to be how it works for
just like General radiation effects I mean essentially what happens is you get things being ionized in the body uh so you could ionize water and the body's 70% water so you get all the different fragments of water flying around in your cells and they could then interact with your DNA and cause the DNA to become damaged but if you had something that radiation chemists call a scavenger that would preferentially interact with those water fragments it would prevent it from
interacting with your DNA and protect it and I guess most people have heard of antioxidants I think from Beauty and I don't know if people really know what an antioxidant does no something that prevents oxidative stress or damage to molecules in the body through oxidation so it's a similar thing it mops up some of these chemicals that may cause oxidative stress before they have that chemical interaction that makes sense so you hear there's a lot of it in things like green
tea and apples and tomatoes so potentially eating more of those things could help protect you from radiation but it depends on the dose rate if your body is being blasted with huge amounts of radiation I don't think there much and antioxidants or anything will do unfortunately so in some of the Star Trek episodes uh it's just fantasy unfortunately will be that's a shame you'd have to almost get your body weight in antioxidant for it to be able to interact with it instead of you so
you would have to not be there effectively yeah the way you control that in the industry is first of all you figure out what the dose is you figure out how long you can stay in a particular area and then you figure out if you need extra shielding so a lot of the work we do is do like big thick concrete walls with um meter thick lead glass window so we can see what we're doing but not get much of a radiation dose so that's a slightly more practical way of doing it but I
guess in Star Trek where it was like emergency situations needs must yes and I don't think that spray was atomized lead because that's toxic in itself yeah but they might have different body chemistry at that point and they may be resistive to lead um in that case wouldn't you just Eng near the human body to be more radiation tolerant than it already is but what would be radiation tolerant as a human body yeah I guess it would be able to repair itself really quickly which it does
quite well anyway there are loads of different repair mechanisms for fixing damaged DNA and whatever else it just do it faster whether you can do it faster because then you're getting down to how fast chemical reactions can occur I don't know I feel like we could do an entire episode on just this though and get very distracted by biochemistry and I'm not a biochemist I am certainly not either and it's it's been a while since I looked at chemical reaction engineering yeah maybe let's not go
there yeah but you mentioned using a spray right and uh that reminds me of another movie not injecting something into your body with a hypos spray but in Die Hard five A Good Day to Die Hard great name they they went into chobble and they were wearing hazmat suits and they said oh radiation is pooling in this area but it's okay we have a spray and they sprayed something around the room and then took off their hazmat suits okay could that been a spray full of
your antioxidants Wait no that's not how it works no wouldn't it have been funny if it did though um I suspect they have been somewhat Artful with the truth because there is a spray that as far as I'm aware is used in chin Noble oh but what it does it's inside the reactor building there's a whole load of dust that may be Radioactive active and it can get into the air and it can then settle on things or it could maybe Escape through fishes I think this is before they put the new
confinement Arc over it a few years ago but I might be misremembering this but essentially they just spray water into the air and it makes that dust drop out of the air so it makes it a bit less likely that you'll have a radiation in air Incident That's it there's still radiation there it's just not radioactive particles flying around it's like when you're in a smoggy city particularly like in summer that seems to be more hazy and then it rains and then you're like wow the air is a lot
clearer now but if they were saying it was pooling what do they mean was it radioactive water I think when they said the radiation is pooling yes they meant the water that is made some of that radioactive particul come out of the air and is now collecting in one place I still would not take off my hazmat suit in that condition though cuz it just makes sense to leave it on just in case to me it seems like like an unnecessary risk to take you might still breathe it
in it's not like it's actually fixed to the ground and to me what is the Hazmat suit doing cuz it's probably not lead lined even if it was lead lined oh my God could you imagine how how you'd move around in there it seems more like it's preventing the water coming into contact with their skin or their clothes and sticking to them essentially exactly it stops you getting contaminated it would I guess it would stop Alpha and maybe beta radiation but you're still going to
get a radiation dose if there are gamma rise around there so yeah that hazmat suits just stopping you from being contaminated yeah keep it on I would unless you've got some monitoring equipment that says it's fine take it off that's been assessed by experts yeah leave it on and did they no did they have those people no no this is where I say they were very Artful with the truth which which it was kind of annoying to watch because they'd sort of made up something that was just a bit
silly just I don't know for a plot point and I get Die Hard five isn't meant to be particularly educational and that's kind of the fun of the Die Hard films yes but still when it comes to radiation science I just think oh please it's it's so misconstrued anyway don't make it worse but in this sense because they were so lacked with safety does that mean that actually radiation is low risk well in that particular madeup scenario it was like they had this magical spray that just halted all
radiation wouldn't that be great it would make radiation safety work a lot easier so yeah I guess they were sort of showing oh look radiation's fine just spray something over it that's it job done if that spray did exist that would make your life way easier is there anything else that you would want in the world of radioactive protection um for the work that I was doing because it was so well controlled anyway probably not I think what I would like to see though is
things like the media saying oh radioactive waste dump okay no no one just dumps radioactive waste it's all highly controlled I see and it will go into this like incredibly well engineered store that will keep it locked up far away from people for quite a long time so I think I'd rather see more sort of a change in how it's portrayed in mass media and in pop culture things like this rather than a change to you know some fundamental science it would be very cool though if someone came up with
some amazing science that said yeah people it's now fine to handle this thing this thing is definitely not scary so I was having a thought about what seems to be one of the only ways to prevent gamma rays is lead and I just wondered is there another material water's actually pretty good at shielding so as concrete cuz it contains a lot of water you just need quite a lot of it used fuel is stored in ponds of water for that reason I thought it was to also bring down the temperature as
well it is yeah but it also acts as shielding and so does the concrete around it as well the best thing you can do is probably just to put more distance between yourself and gamma radiation as well depending on how strong the source is it's quite a big distance maybe distance and things in between yeah get behind a big building it's a good idea go inside and shut all the windows yeah see there are loads of ways to be safe working with radiation so it's it's fairly well known it's just
you got to stop look and listen exactly pay attention to what that sign really means and uh follow procedures yeah yeah and I mean there there's an a certain amount of radiation your body can absorb it's not going to cause any problems so some radiation is fine I'm not saying go out there and find some radioactive sources though no that's definitely not what we're advocating here no don't take apart your smoke detector that's got a radioactive Source in it's there for a reason it
helps detect the smoke it's a good good point yeah that's another helpful use of radiation so this seems like a good place to leave it I think we've we've covered a lot about the uses of radiation what it can be used for and what we think it might been an exaggeration of the truth or just made or speak to you next time the views expressed in this podcast belong in tell you to the person that said them they do not represent any industry or organization if you enjoyed listening to
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