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  • MICHAEL SHORT: So, today we're going

  • to get into the most politically and emotionally fraught

  • topic of this course for stuff on chemical

  • and biological effects of radiation.

  • Now that you know the units of dose, background dose,

  • we're going to talk about what ionizing radiation does

  • in the body, to cells, to other things,

  • and we're going to get into a lot of the feelings associated

  • with it.

  • And by the end of this lecture, or Thursday,

  • I'm going to teach you guys how to smell bullshit.

  • Because we're going to go through one of millions

  • of internet articles about things that cause cancer,

  • that don't cause cancer.

  • In this case, it's going to be radiation from cell phones.

  • So I'm going to try to reserve at least 10 minutes

  • at the end of this class for us to go through a bunch of quote,

  • unquote, studies and misinterpretations

  • of those conclusions.

  • And I was going to pick my favorite of the 44 studies,

  • and looking through them all, my favorite are all of them.

  • AUDIENCE: [LAUGHTER]

  • MICHAEL SHORT: So we'll see how many we can get through.

  • But let's get into the science first,

  • so you can understand a bit about what goes on

  • with ionizing radiation.

  • Like radiation damage in materials,

  • radiation damage and biological systems

  • is an extremely multi-time-scale process.

  • Everything from the physical stage, or the ballistic stage,

  • of radiation damage to biological tissues

  • acting on femtoseconds, where this

  • is just the physical knocking about atoms and creation

  • of free radicals, these ionized species, which in metals you

  • wouldn't care about, in biological organisms you

  • do because then they undergo chemical

  • reactions from the initial movement

  • and creation of other strange radiolytic species

  • and the diffusion and reaction of those things,

  • which starts and finishes in about a

  • microsecond, before most of these things are neutralized.

  • And then, later on, the buildup of those oxidative byproducts

  • of these chemical reactions undergo the biological stages

  • of radiation damage.

  • All of the free radicals with biological molecules

  • have reacted within a millisecond.

  • So radiation goes in, a millisecond later the damage

  • is done.

  • Then you start to affect, let's say, cell division.

  • It takes, on average, minutes for a rapidly dividing cell

  • to undergo a division.

  • That's when the effects would first be

  • manifest from a DNA mutation.

  • But then it'd take things like weeks,

  • or years for these sorts of things

  • to manifest in a health-related aspect.

  • So, the division of one cancerous cell into two

  • won't change the way your body functions,

  • but the doubling in size of a tumor that blocks other tissue

  • absolutely would.

  • And so, it all starts in this sub-femtosecond regime,

  • when most of you-- well, for this entire year,

  • we've been approximating humans as water.

  • We're going to continue to do so for the purposes

  • of these biological effects.

  • So, let's say you, a giant sack of water,

  • gets irradiated by a gamma ray.

  • And that gamma ray undergoes Compton scattering.

  • Which, now you know how to tell what the energy of the Compton

  • electron would be.

  • We never talked about what happens with the molecule where

  • it came from.

  • That molecule remains ionized.

  • And since you're not especially electrically conductive,

  • they're not neutralized immediately.

  • And you can be left over with either a free radical

  • or an electron in an excited state.

  • And then what happens next is the whole basis

  • of radiation damage to biological organisms.

  • These free radicals can then encounter other ones,

  • and let's say an H2O+, can very quickly find a neighboring

  • water molecule, which they're almost touching and form OH

  • and H3O.

  • This is better known as H+, and that OH is a kind of unstable

  • molecule.

  • And these excited electrons here can also become these

  • H2O+'s, leading to this cascade of what we call radiolysis

  • reactions.

  • There's a few of them listed here,

  • things like an OH plus an aqueous electron,

  • which could come from anywhere, like Compton scattering,

  • like any other biological process that frees an electron,

  • can make another OH-.

  • So you can locally change the pH inside the cell

  • that you happen to be irradiating.

  • Or, let's say any of these oxidative byproducts

  • could encounter DNA.

  • Rip off or add an electron to one of the guanine, thymine,

  • or other two or three bases in DNA or RNA,

  • then you've changed the genetic code of the cell.

  • In the progression of these radiologists byproducts,

  • like I mentioned, whether you go by excitation or ionization,

  • then you start to build up these six species-- these five

  • species tend to be-- or these six ones

  • tend to be the ending byproducts of a whole host

  • of radiolysis reactions.

  • And don't worry, you're never going

  • to have to memorize all the radiolysis

  • reactions because the mechanism map is fairly complicated

  • and there are multiple routes to creating each one.

  • But the ones that are highlighted here

  • in these squares, are the ones that

  • end up building up in your body, things like peroxide.

  • Has anyone ever put peroxide on a wound before?

  • What happens?

  • Yell it out.

  • AUDIENCE: It bubbles up.

  • MICHAEL SHORT: Bubbles up.

  • What happens when you form peroxide in your body

  • from radiation?

  • AUDIENCE: It bubbles up.

  • MICHAEL SHORT: Well, luckily it doesn't quite

  • bubble up on the macro scale level,

  • but it is a vigorous oxidizer.

  • 90% H2O2 is used as rocket fuel, as the oxidizing species

  • in rocket fuel.

  • You don't make 90% H2O2 from getting irradiated,

  • but every molecule counts.

  • Things like O2, you're shifting the amount

  • of oxygen in the cells.

  • And then there's things like these superoxide radicals,

  • or H2O-, H2O+, or all these other things that are available

  • to rip off or add an electron to something else that normally

  • wouldn't have it.

  • And the list of these potential reactions,

  • as well as their equilibrium constants and activation

  • energy, is huge.

  • Here's half of it.

  • Notice a lot of these equilibrium

  • constants shift really strongly one way or the other.

  • So, just because these molecules are made,

  • doesn't mean that all of them end up

  • staying and doing damage.

  • But unless these rate constants are either 0 or infinity,

  • there's going to be some dynamic equilibrium of these reactions.

  • So, once in a while, some of these free radicals

  • will escape the cloud of chemical change and charge

  • and get to something else.

  • Here's the other half of the equation set.

  • And it's under debate just how many of these reactions

  • there actually are.

  • Like, how often would O2- radicals combine with water,

  • which you can see is not quite set in the reaction,

  • to form [? HO2 - NO2 NH+ ?] Kind of a strange little reaction

  • right there.

  • Actually, a lot of them are quite strange.

  • You don't usually think of them happening

  • because these are very transient reactions, whose byproducts

  • do build up.

  • And that's the chemical basis for radiation damage

  • to biological tissues.

  • Now, once those chemical products form,

  • they have to move or diffuse.

  • So you can actually calculate or get diffusion coefficients

  • for some of these oxidizing species,

  • as well as compute an average radius

  • that they'll remove before undergoing a reaction.

  • So this is part of the basis for why

  • alpha radiation is a lot more damaging than gamma radiation.

  • Chances are, if you incorporate an alpha emitter into the cell,

  • it does a whole bunch of damage.

  • That damage consists of these oxidative chemical species,

  • that, if they're that far away from neighboring atoms that

  • happen to be in DNA, they might do some damage.

  • Whereas, isolated Compton scatters and photoelectric

  • exhortations from gamma radiation, not so much.

  • Chances are you hit random water in the cell that

  • isn't quite close to anything, fragile, and not much happens.

  • But you can also see this by looking at charged particle

  • tracks.

  • These things can actually be experimentally measured.

  • By firing electrons into gel or film or something like that,

  • you can actually see tracks of ionization

  • and watch them as a function of time.

  • In this case, it's a simulation of a charged particle

  • track at different timescales.

  • So, right here, this 10 to the minus 12

  • for the time in seconds, tells you

  • where these radiolysis products are.

  • And the N number, here, tells you how many of those remain.

  • So after a picosecond, you can pretty much just

  • trace out the path that the electron took, starts off right

  • here.

  • What do you guys notice about the density

  • of the charged particle track as it moves from the source

  • to the end?

  • AUDIENCE: It's much more dense at the end.

  • MICHAEL SHORT: It's much more dense at the end.

  • And why do you think that is?

  • AUDIENCE: Stopping power.

  • MICHAEL SHORT: OK.

  • More than just-- yeah.

  • Stopping power, yes, but fill in the beginning

  • and end of that sentence.

  • Chris, do you have your hand up?

  • AUDIENCE: [? It's all good. ?] So, it's a charged particle,

  • so it drops off most of it's energy where it has the least

  • amount of energy, so it does the most damage [INAUDIBLE]..

  • MICHAEL SHORT: That's right.

  • So, you're actually visualizing the change

  • in stopping power as a function of charged particle energy.

  • It comes in, has a very high energy.

  • And it might knock a little radiation damage cascade

  • by hitting another electron, which can have

  • its own shower of ionization.

  • And then it moves while doing nothing, in this straight line,

  • until it hits another one.

  • And notice right at the end, that's

  • where the densest amount of damage is done because that's

  • where the stopping power is the highest.

  • It's also where the energy is the lowest.

  • So, this is where the worlds of and physics collide.

  • You can actually visualize stopping power, like actually

  • visually in gel or on film or on a computer

  • by watching these charged particle tracks.

  • And after 10 to the minus 12 seconds,

  • all the ballistics are over.

  • Then you end up with diffusion and reaction.

  • So, it's going to be a balance between these charged particles

  • moving away from each other and finding something else,

  • or finding each other and re-combining.

  • And that's why, as you go up in timescale,

  • the particle tracks get more and more diffuse

  • and the number of these remaining free radicals

  • goes down until you level out at about a microsecond,

  • when all of the different particles

  • are so spread out that there are none

  • touching each other anymore.

  • To refresh your memory a bit from a few seconds ago,

  • take a look at some of the charge

  • states of these oxidative byproducts.

  • Some of them plus, some of them minus, sum of them excited,

  • all over the place.

  • So they can react with each other, which

  • is something you'd want to encourage so that they

  • don't go and find something else, causing

  • biological damage.

  • There's a question on last year's OCW problem set,

  • that I'm not giving you for this one, which

  • is, calculate the radiation resistance you

  • would get by getting cryogenically frozen.

  • So here's a question that I don't

  • think a lot of cryogenicists ask themselves,

  • if you want to preserve a human for 10,000 years

  • and wake them up later, how much radiation damage

  • are you going to get?

  • Ever think there's a cryogenicist that

  • ask themselves that question?

  • I don't actually know.

  • But it's not a question I've ever heard before,

  • which is why I made it a problem set question.

  • Because I know the answer is not out there.

  • I looked for a while.

  • Let's switch particles for a second and look

  • at the charged particle tracks from a proton.

  • What differences do you see between the proton

  • and the electron charged particle track?

  • So, proton, electron.

  • Proton, electron.

  • AUDIENCE: There's no curve.

  • MICHAEL SHORT: There's what?

  • AUDIENCE: There's curve.

  • It's straight.

  • MICHAEL SHORT: Its straight.

  • Why do you think it's straight?

  • Why does anyone think it's straight?

  • AUDIENCE: They're bigger.

  • MICHAEL SHORT: They are bigger, more massive.

  • So the same deflection, the same transfer of momentum,

  • to an electron using our beloved hollow cylinder approximation

  • thing, causes less of a change in direction for a proton

  • as it does an electron.

  • The forces are the same.

  • They're both just a plus or minus 1 hitting a plus

  • or minus 1 charge.

  • But the mass is quite different on the proton,

  • so it doesn't get deflected as much,

  • which is why the charged particle

  • tracks are so straight.

  • Now, what are these things here?

  • What are those offshoots?

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: They're secondary charged particle tracks.

  • So, let's say a proton hits an electron,

  • that electron can have any amount of energy, probably

  • going to be lower than the proton did.

  • And it's going to cause its own little damage

  • cascade right there.

  • And, just like before, you can track the number of these

  • charged particle trucks moving from 5000 to about 1000,

  • between, let's say, 10 picoseconds

  • and a little less than a microsecond.

  • And once these charged particles have spread out or diffused

  • away, chances are recombination has gone down quite a bit

  • and they're going to go react with other things.

  • And this is a perfect analogy to radiation damage in metal.

  • So, radiation damage in biology is like radiation damage

  • in material science.

  • You have this initial cluster of damage,

  • in materials it's usually vacancies or intestinals,

  • in biology it's charged particles.

  • But when they're in a dense cascade

  • they can recombine with each other.

  • And the ones that miss each other

  • go off to find either other defects in the material

  • or other atoms in your cells.

  • It's a very fitting analogy.

  • Yeah?

  • AUDIENCE: How come we don't see like a denser [INAUDIBLE]

  • to the proton [INAUDIBLE] electrons?

  • MICHAEL SHORT: Let's see.

  • I don't know if we see the whole charged particle track here.

  • You're right, it doesn't look like the density changes

  • very much.

  • You can't even really tell where the source is.

  • We may not be looking at the whole thing.

  • Here's another question.

  • So, it's a 2 MeV proton.

  • That scale bar is 0.1 microns.

  • Let's do a quick simulation to verify this idea.

  • Luckily we have the tools to do this,

  • soon as I clone my screen.

  • Let's use SRIM and find out what is the range of 2 MeV protons

  • in water.

  • And if it's more than about a micron, which is what's shown--

  • well, let's say, that's 2 microns.

  • If it's more than 2 microns, what's shown on the screen,

  • it means we're not seeing the whole track.

  • SRIM.

  • Good, you can see it.

  • So let's say, hydrogen at 2 MeV, going into something consisting

  • of H and O in a ratio of 2:1, make

  • sure its density is correct for room temperature water,

  • and let's look at a range of 25 microns,

  • because I kind of already know the answer.

  • AUDIENCE: [LAUGHTER]

  • MICHAEL SHORT: Much more than 25 microns.

  • So, our initial assertion was correct.

  • Let's actually find out what the range is.

  • Let's put 40 microns.

  • Whew, it's a little more than I thought.

  • Protons in water, at just 2 MeV.

  • Let's fly tons of them.

  • Wait til we get about 1,000.

  • Look at the range.

  • Make it bigger so you can read it.

  • 75 microns.

  • 75.5 micron range.

  • There you go.

  • Let's go back to the big one.

  • So, there you go.

  • If this scale bar is 0.1 microns, you're looking about 2

  • of the 75 microns of charged particle track.

  • Interesting, no one picked up that question last year,

  • but I'm glad you did.

  • I'm glad we were able to show you where it comes from.

  • So this will look quite different

  • if you're looking at the end of the charged particle track.

  • Cool.

  • Good question.

  • To look really, really close up, you

  • see a lot more of this branching again.

  • So whenever a proton strikes, let's say another atom

  • or an electron, you get your own little dense damage cascade.

  • And look at that, not much until the very end

  • when you get this cloud of damage popping off at the end.

  • So, yet more examples of the physics that you've learned

  • popping up in biological systems.

  • The difference is it's water not metal,

  • but otherwise everything's the same.

  • And then we get to what's called G-values.

  • I don't know why it's called G, but I'll

  • tell you what they mean.

  • It's the number of each species, per 100 MeV, found later,

  • at let's say, 0.28 microseconds, or typically 1 microsecond,

  • for different particles of various energies.

  • These are relative effectiveness' of these

  • particles at different energies to leave oxidative byproducts

  • by.

  • So there's a few things that are wrapped up into these G-values.

  • So, notice that, in this case, here's

  • a G-value for electron energy.

  • At different energies, you'll have

  • different amounts of OH, H3O in such, per 100 eV of energy.

  • So the unit of G-values here, it's

  • like number of chemical species per 100 eV of energy.

  • So it's an energy normalized measure of the effectiveness

  • of radiation making chemicals.

  • Does make sense to folks?

  • If not, raise your hand and I'll try to re-explain.

  • OK.

  • AUDIENCE: Please repeat it.

  • MICHAEL SHORT: Yep.

  • So a G-value, it's got units in concentration per unit energy.

  • And it's a measure of how many chemicals

  • a given particle will make as a function of its energy.

  • And these particles are the ones that survive the recombination

  • and end up diffusing to other species.

  • So, these G-values, it's kind of like how many

  • oxidative species are made that go off and damage other things?

  • Let's look at some trends right here.

  • For things like OH, for electrons,

  • what sort of patterns do you notice in the data?

  • And take a sec to parse some of these numbers.

  • Just look at the top three rows.

  • What pattern do you see?

  • AUDIENCE: Starts high and then goes--

  • MICHAEL SHORT: Starts high, goes low, goes high again.

  • Why do you think that is?

  • Straight from the physics.

  • At super low energies, 100 eV electron,

  • you'll make, on average, 1 OH radical

  • for every 100 eV of energy.

  • As you increase in energy, you start

  • making fewer and fewer per unit--

  • actually, that's not the one I want to look at.

  • That's a different species.

  • Let's see.

  • No, that is.

  • OK.

  • That follows the pattern that we're looking for.

  • AUDIENCE: Does the high energy includes

  • stuff that's created from causing secondary cascades?

  • MICHAEL SHORT: Oh, yeah.

  • This is just total number from everything.

  • Right?

  • It's just the number of each chemical species left over

  • after a microsecond.

  • So what do you think could cause this initial increase

  • and then decrease and then increase?

  • AUDIENCE: Is it because of the cross-sections

  • of different particles?

  • MICHAEL SHORT: Part of it.

  • The cross-sections that also go into the stopping power.

  • That's part of the answer.

  • So at really low energies, you're already

  • at your stopping power peak.

  • And that way, for the little bit of energy you have,

  • chances are it's going to ionize different things.

  • Then as you increase your energy,

  • you have more and more of that range

  • of the particle in the lower stopping power region.

  • So, you'll have more of the-- let's see.

  • You'll have more and more of that particle--

  • let me try and phrase this quite well.

  • Let's go back to the charged particle tracks for electrons,

  • and I'll get this-- yeah, here we go.

  • So, when you're electron comes in a really, really low energy,

  • you're in that region right there.

  • Chances are you're going to make a lot

  • of those oxidative byproducts.

  • And then as you go a little higher in energy,

  • you make fewer per unit distance--

  • or you make fewer per unit energy.

  • You can think of that as the spread, right there.

  • But then also, as you go way higher in energy,

  • your ability to ionize increases.

  • So you've got that sort of 1 over E term

  • in stopping power making things worse.

  • And you've got that log of E term

  • in stopping power making things better.

  • And if we go back to the data right here,

  • for those top three or four, it tends

  • to follow that trend pretty well.

  • Now what about things like H202?

  • What sort of trend do you see there?

  • AUDIENCE: The opposite.

  • MICHAEL SHORT: The opposite.

  • So, I'll give you a hint.

  • H2O2 isn't directly made by radiolysis,

  • it tends to occur by reaction of other radiolysis products.

  • So it's like a secondary chemical,

  • not a primary produced chemical.

  • So, why do you think H2O2 follows the opposite trend?

  • AUDIENCE: It comes from the-- not the decay,

  • but like a reaction from one of the previous ones, that there's

  • more of that first species there, that it

  • hasn't reacted to form it yet.

  • But once it is lowered, that means

  • it's made more of the H2O2.

  • MICHAEL SHORT: Sure.

  • AUDIENCE: And then vice versa.

  • MICHAEL SHORT: Yeah.

  • So, to rephrase what Sarah said, in this energy range

  • right here, you're producing this fairly dense cascade

  • of oxidative byproducts.

  • When those reactions occur, they tend

  • to make things like H2O2, something that's

  • not made directly from radiolysis, but indirectly

  • from recombination of those chemicals.

  • And then as you raise the energy more and more, to like 20 keV,

  • you start making those primary products more spread out.

  • They're not as close to each other.

  • They don't recombine as much.

  • They don't make as much H2O2.

  • They'll tend, instead, to spread out a little more.

  • So more will survive.

  • More of these primary ones will survive, and not

  • react to make as many of the secondary ones.

  • So, how is that explanation fitting with you guys?

  • Cool.

  • So, it's a balance between intermediate energies.

  • You make a whole lot of primary ones, which

  • are so close that they react to make the secondary species much

  • more easily.

  • As you raise the energy of the particles going in,

  • you make more isolated primaries that can't find each other,

  • and they don't make as many secondaries per unit energy.

  • Yeah?

  • AUDIENCE: How come for like the 100 eV H2O2 it's less?

  • Because since it's making a lot of the initial,

  • or the primary, byproducts, wouldn't you

  • expect it to also make a lot of the secondary

  • because they're also close together?

  • MICHAEL SHORT: You might, except at very low energies,

  • our idea of stopping power isn't quite as complete.

  • So, by what other processes can electrons lose energy

  • at really low energies?

  • You could have a deflection without an ionization, right?

  • Just a simple-- let's say, you could have an excitation,

  • you could have just coulomb deflection,

  • you can have neutralization.

  • You can have all those really, really low energy things

  • that go on, that don't end up producing as many ionizations.

  • Because you need to produce an ionization or an excitation

  • to kick off radiolysis.

  • So then, when you get high enough in energy,

  • and chances are you'll ionize rather than undergo

  • one of these really low energy inner loss mechanisms,

  • then you start making more of the primaries,

  • but densely, which make more of the secondaries.

  • Then as you go even higher in energy,

  • you still make tons of primaries,

  • but since they're spread out more,

  • since the stopping power is lower,

  • they don't find each other and they

  • don't make as many secondaries.

  • So, let's look at some other numbers and trends,

  • different particles.

  • First of all, for protons and for alpha particles,

  • note here that the scales are in MeV.

  • Whereas, the G-Value is for electrons in the keV range,

  • and for protons in the MeV range are pretty much the same,

  • on the same order of magnitude.

  • Anyone have any idea why?

  • AUDIENCE: They're heavier.

  • MICHAEL SHORT: They're heavier.

  • And then what does that lead to in terms of a stopping power?

  • AUDIENCE: They're easier to stop.

  • MICHAEL SHORT: They're actually harder to stop.

  • If they're heavier, than the deflection of an electron

  • doesn't stop them as much.

  • And so that way, more of these proton and alpha radiolysis

  • products are going to be more spread out.

  • So you get the same number per 100 MeV,

  • in the MeV range, as you do for electrons

  • at a much lower energy.

  • But then alphas also have this interesting thing

  • that they're doubly charged, so that those coulomb

  • forces, remember it's by Z squared,

  • so it's four times as strong.

  • So, let's see, how do they compare?

  • Yeah.

  • There aren't really enough data to draw those nice trends

  • that you could see from electrons.

  • But we do have some other interesting trends

  • in the G-values as a function of temperature.

  • So these right here are G-values for H and OH

  • by gamma rays, which are two primary species.

  • And here we've graphed them as a function of temperature.

  • Why do you think the G-values, or the amount

  • of radiolysis products that survive a microsecond, increase

  • with temperature?

  • What's this a competing force or a balance between?

  • So once these products are made, what are the two things

  • that they can do?

  • Anyone?

  • AUDIENCE: Recombine or diffuse.

  • MICHAEL SHORT: Recombine or diffuse.

  • Good.

  • Which of these will increase much more strongly

  • with temperature?

  • AUDIENCE: Diffusion.

  • MICHAEL SHORT: Diffusion.

  • If they spread out more at higher temperature, then

  • they'll separate from each other and not recombine as much.

  • So a whole bunch will be made, no matter what,

  • in a matter of femtoseconds.

  • But at a higher temperature, more of them

  • diffuse away from each other and survive the cascade,

  • rather than recombining.

  • And so that's why, when you look at any primary species, H2 or H

  • or anything like that, you're going

  • to see an increase in G-values with temperature.

  • What do you guys think is going to happen

  • to these secondary byproducts with temperature?

  • AUDIENCE: Decrease with temperature.

  • MICHAEL SHORT: Decrease.

  • And why do you say so?

  • AUDIENCE: Well, if they're made from the primary products

  • and the primary products are surviving more because they're

  • separating, then the secondary ones are just going to be less.

  • MICHAEL SHORT: Yeah.

  • If the primary ones are surviving more,

  • you're not going to make as many secondary ones.

  • And that's just what we see.

  • Number of free electrons left, or especially things

  • like the amount of H2O2, it's all going to be in balance.

  • And if more primaries survive, you

  • don't make as many secondaries as a function of temperature.

  • One, these heavy ones are slower to diffuse.

  • But two, they're not made as much

  • because the primaries escape each others pull and go off

  • to damage something else.

  • In a reactor, this would be metals causing oxidation.

  • In a body this would be you.

  • And so let's get into the materials aspect of this

  • to give you a more--

  • a less biologically damaging view

  • of what can radiolysis really do.

  • It's quite relevant to all reactors, including

  • the Fukushima reactor.

  • The idea there is that the reactor

  • was flooded with seawater, which introduces chlorine,

  • which greatly changes the balance

  • of radiolytic byproducts.

  • And this can actually be directly studied.

  • There's an experiment just a few years ago--

  • two years ago, where they wanted to figure out

  • what is the influence of radiolysis on corrosion?

  • If you're making all of these Hs and OH-s and H2O+s,

  • does it change the corrosion rate of materials

  • in the reactor?

  • So they built a high-pressure cell,

  • that they fill with high-pressure, high-temperature

  • water.

  • And they've got this little disk of metal with a thin membrane

  • right there.

  • It's thin enough that protons can pass through it

  • and cause radiolysis to occur right in this little pocket

  • where the water is.

  • And so where the protons are, you get radiolysis.

  • Where the protons aren't, you get regular old water

  • corrosion.

  • And the results are pretty astounding.

  • You can see the irradiated zone in extra oxide thickness.

  • So you can see where the protons were

  • because radiolysis sped up the corrosion

  • rate as a single effect.

  • Right nearby, not 100 microns away,

  • was the same water, at the same temperature and pressure, just

  • no protons and no radiolysis.

  • To look at a cross-section, you can very clearly

  • see the difference in oxide thickness

  • way out in the unirradiated zone or in the irradiated zone.

  • And you can tell right here how many

  • protons there were, until right over here

  • where there were none.

  • So it's a very striking example of, well,

  • this is what radiolysis does in reactors.

  • And we actually do things in reactors

  • to suppress radiolysis.

  • We inject hydrogen gas.

  • So there's a hydrogen gas overpressure injected.

  • One of the main reasons is to suppress radiolysis.

  • Because if I jump back to any of these reactions, a lot of them

  • involve H2.

  • And if you dump a whole bunch of H2 into the reactor,

  • you push the reaction backwards in the other direction.

  • From straight up chemistry, if you add a reactant

  • and add a product, you push the equilibrium

  • in the other direction.

  • That's why we do this in terms of injecting hydrogen

  • into light water reactors.

  • And if you look at the amount of hydrogen injected

  • in a PWR, a pressurized water reactor, which comprises 2/3

  • of the reactors in the country, it's

  • like 20 to 30 cubic centimeters per kilogram of dissolved

  • hydrogen. That's quite a bit.

  • And the whole idea there is to suppress radiolysis

  • and suppress corrosion.

  • So I find it to be pretty cool.

  • So a knowledge of G-values can keep your reactor

  • from corroding.

  • Then let's get into the biological effects.

  • In the end, for the long-term effect

  • it's all about what happens to DNA.

  • Because if a cell mutates, it can either

  • kill the cell so that it can't replicate,

  • or you can cause a mutation that might

  • make some sort of a change and change the cell's function.

  • And so you may imagine, a lot of this stuff

  • is done in LET, linear energy transfer.

  • Again, another word for stopping power.

  • If you look at the density of these damaged cascades

  • as a function of stopping power, LET.

  • You can see that for high-energy electrons, or beta particles,

  • they just bounce around with a lot of distance

  • between interactions, causing very relatively little damage

  • on the way.

  • For Auger electrons, again electrons,

  • but at a much lower energy.

  • They're at the end of their stopping power curve

  • and they cause a lot more damage wherever they're

  • emitted because already, they're going to make a much denser

  • damage cascade.

  • Alpha particles just go slamming through.

  • It's like rolling a tank through your cell pretty much.

  • Because there's going to be a ton of interactions

  • from charged particle interactions,

  • you won't really change the path of that alpha

  • because an electron imparts very little momentum

  • to an alpha particle.

  • And if DNA happens to be in the way, it's going to get damaged.

  • This is a lot of the reason why there

  • is relative effectiveness of different types of radiation.

  • We talked last week about these quality factors,

  • gamma rays are 1 electrons tend to be pretty close to 1

  • alphas tend to be 20.

  • Because the same energy alpha particle

  • will impart a ton more damage locally than the same energy

  • beta particle.

  • So can you guys see visually where these quality factors

  • come from?

  • Cool.

  • And there's two types of DNA damage, direct and indirect.

  • Direct damage is what you might think

  • radiation comes in and ionizes something in the DNA,

  • either causing, let's say, 2 thymine-based bridge,

  • like a kink in the DNA, or destroying it

  • or doing anything.

  • But most of the damage is done indirectly

  • because the amount of volume of DNA in your cells

  • is extremely low.

  • Has anyone ever done the old high school bio experiment,

  • where you extract DNA from onions?

  • AUDIENCE: Yes.

  • AUDIENCE: Strawberries.

  • MICHAEL SHORT: Strawberries.

  • Anything?

  • So how did you do it?

  • Anyone remember how this was done?

  • AUDIENCE: Some chemicals and stuff.

  • AUDIENCE: You have to mix in good solution

  • with a bunch of good stuff and [INAUDIBLE]

  • MICHAEL SHORT: So you take, let's say, an onion,

  • mix it in solution with a bunch of stuff,

  • and you end up with this gigantic booger,

  • which happens to be DNA.

  • It's like a three-foot snot thing.

  • But what was the volume of the DNA compared

  • to the volume of the onion?

  • AUDIENCE: Quite small.

  • MICHAEL SHORT: Quite small.

  • There's not a lot of DNA in cells.

  • So the direct damage route, while still there,

  • comprises very little of the damage done to tissue.

  • Mostly it's indirect because surrounding

  • all DNA is the rest of your cellular fluid, which

  • consists mostly of water.

  • And as we've seen all today, water undergoes radiolysis.

  • Those radiolytic byproducts can diffuse, find their way to DNA,

  • and cause the same sort of ionization

  • that direct radiation would do.

  • And since that volume is much larger,

  • let's say the hollow cylinder of water surrounding your DNA,

  • this is the most likely route to cellular damage.

  • And--

  • Actually I want to skip ahead to something real quick,

  • you can actually use that to your advantage

  • because it can kill tumor cells.

  • So tumors are rapidly dividing masses of cancer cells.

  • If those cells are rapidly dividing,

  • then DNA is being replicated much more readily.

  • So you can inject something that will

  • bind to DNA, like this little chemical right

  • here, this Iodine-125, whatever, whatever, which

  • mimics thymidine, something that would be found in your DNA,

  • but absorbs radiation much better.

  • So you can inject this iodine-containing organic

  • molecule, which binds somehow to DNA.

  • I'm not going to even guess how it works.

  • But, if you want this to get damaged,

  • then you want-- let's say, your DNA to get preferably damaged,

  • the tumors are replicating faster,

  • they're going to incur more damage from the same amount

  • of radiation.

  • So the same process that causes cancer

  • can be used to cure cancer, interestingly enough.

  • And so, good, we do have about 10 or 12 minutes

  • to talk pseudoscience.

  • So now that you know a little bit about how

  • radiation can cause cancer and mutations

  • and you know a lot of the physics behind how much energy

  • do you need to cause an ionization,

  • let's start knocking off these questions one by one.

  • So, this field, more than any, is

  • fraught with garbage, absolute garbage science.

  • I won't even say pseudoscience because that almost

  • makes it sound half legit.

  • Garbage, misinterpretations, lies, poorly done studies,

  • misinterpretations of abstracts and conclusions.

  • And today I'd like to focus on cell phones

  • and do they cause cancer?

  • Very hot topic.

  • There's lots of people with predetermined agendas that

  • want to say all electromagnetic radiation is bad

  • and we should go back to an agrarian society

  • where nothing happened.

  • Well, I'll give you a hint, Cambodia tried that

  • and it didn't turn out too well.

  • People have interesting notions of what's real and what's not.

  • So let's start looking at some of these.

  • There's an article written by this fellow, Lloyd Burrell,

  • around November, 2014.

  • It looks like it was republished somewhere in 2016.

  • Let's just start looking at the facts.

  • So, what I want to start doing here

  • is cultivating your nose to be able to smell bullshit

  • because this is a lot of what you're going to be doing,

  • in terms of public outreach.

  • As nuclear scientists you will be called on

  • to provide expert advice and say whether things are real or not,

  • explain why, and do it in an empathetic way

  • so as not to make people feel stupid.

  • Because it's very easy for someone to read this and think,

  • yeah, I should be afraid.

  • Cell phones cause cancer.

  • It's a natural reaction to feel.

  • Let's take a look at some of these facts.

  • Cell phones emit microwave radio-frequency radiation.

  • True or false?

  • AUDIENCE: True.

  • MICHAEL SHORT: True.

  • Yeah.

  • These are microwave emitters, or RF emitters.

  • What sort of energy is microwave radiation emitted at?

  • Just give me an order of magnitude, MeV, eV, keV.

  • AUDIENCE: MeV?

  • MICHAEL SHORT: Little MeV.

  • Fractions of an eV.

  • It's far beyond the visible range

  • in the lower energy spectrum.

  • Can a milli-electron-volt photon cause an ionization directly?

  • AUDIENCE: No.

  • MICHAEL SHORT: No.

  • Microwaves and RF non-ionizing radiation.

  • They can cook things by heating up water,

  • but they do not cause ionizations the way

  • that ionizing radiation does.

  • This radiation has an ability to penetrate our bodies.

  • True or false?

  • AUDIENCE: Yeah, [INAUDIBLE]

  • True.

  • MICHAEL SHORT: True.

  • It gets through us, right?

  • Radio waves are going through us all the time.

  • Our governments do virtually nothing to protect us

  • from these dangerous.

  • AUDIENCE: Technically, but what dangers?

  • MICHAEL SHORT: Technically, true.

  • Yeah.

  • So this is a classic example of fear mongering, taking

  • a bunch of facts, putting them together

  • to elicit an emotional response that is incorrect.

  • And because the emotional part of the brain

  • kicks in far faster than logical part of the brain, that's

  • how we're wired, it elicits a reaction with a predetermined

  • conclusion.

  • And yet, there is strong evidence, multiple peer

  • reviewed studies--

  • I'm not even going to read the rest of the sentence

  • because I don't want to go on record saying it

  • as if it were true.

  • Let's, instead, look at the studies,

  • because that is the stuff that we should trust.

  • AUDIENCE: [INAUDIBLE] 44 studies.

  • MICHAEL SHORT: 44 studies cited.

  • And let's look at some of the reasons.

  • Let's see, there's a little bit--

  • I have to make it a little smaller.

  • Can you guys still read that at the back?

  • Or actually, no, make it a little bigger

  • and forget the sidebar.

  • That's better.

  • OK.

  • I was going to pick a couple of these to show you

  • and I started going through them and my favorite ones

  • are all of them.

  • Most of the studies are perfectly legitimate,

  • some of them are not.

  • Most of the interpretations by this Lloyd fellow

  • are absolutely wrong, and either done

  • ignorantly, which somewhat forgivable,

  • it can be hard to parse these studies, or intentionally.

  • We don't know which one.

  • Let's look here.

  • "Telecoms giant," et cetera, "commissioned

  • an independent study--" 404, not found.

  • Let's go to the next one.

  • We can't conclude anything from that.

  • The Interphone Study found that: "regular cell phone use

  • significantly increased the risk of gliomas,"

  • some type of tumor, "by 40% with 1,640 hours or more of use."

  • Let's look at the key figure, taken from this paper,

  • and blow it up so you can see it.

  • What do you guys notice about this figure?

  • AUDIENCE: [INAUDIBLE]

  • AUDIENCE: It's so [INAUDIBLE].

  • MICHAEL SHORT: Forget the low resolution.

  • We can't knock that because it might be a copy.

  • No error bars.

  • And what does most of this cell phone

  • use-- and the unit not shown here is,

  • I think it's like hours of use?

  • AUDIENCE: It's all about the same.

  • It's basically all the same.

  • MICHAEL SHORT: Yeah.

  • AUDIENCE: [INAUDIBLE] by any chance [INAUDIBLE]

  • AUDIENCE: The never is actually closest to the 1.

  • MICHAEL SHORT: Except for this one.

  • Blue line is odds ratio.

  • A lot of these things are given in OR, or odds ratio.

  • Let's say the fractional-- or let's

  • say the multiplying factor for increased risk of finding

  • cancer in the variable group compared to the control group.

  • And control and variable are interesting topics

  • I want to make sure people have.

  • So we have the Interphone Study cited in many of these papers.

  • Let's see.

  • OK.

  • Garbage, garbage, opinions, opinions.

  • Let's go find the study.

  • This is something I wish people did more, is go to the study

  • itself.

  • Yeah, the Interphone Study.

  • AUDIENCE: Overall, no increase in risk.

  • [LAUGHTER]

  • MICHAEL SHORT: We'll make this bigger to make it more obvious.

  • So many people-- this article's been cited almost 500 times.

  • I don't know in what capacity because I haven't looked up

  • every citation.

  • But a lot of what this site and other sites do

  • is cite the Interphone Study to say cell phones cause cancer.

  • Read the conclusion.

  • AUDIENCE: Rise of an era.

  • Prevent [INAUDIBLE] interpretation.

  • MICHAEL SHORT: Yes.

  • So this study is not a bogus study.

  • The study was done correctly, reporting

  • ORs, these odds ratios, with 95% confidence intervals.

  • If you just look at the numbers itself,

  • oh man, 1.15 odds ratio, 15% higher incidence of cancer,

  • with a confidence interval that includes less and more.

  • So you cannot conclude with 95% confidence that this data is

  • correct.

  • And the authors very honestly say,

  • no conclusion can be drawn, require further investigation.

  • What does this Lloyd fellow say?

  • AUDIENCE: Cancer.

  • MICHAEL SHORT: Cancer.

  • Yeah.

  • An either accidental or deliberate misinterpretation

  • of the data.

  • OK, let's go to numbers 2 and 3.

  • I don't need those anymore.

  • Let's see, number 2.

  • Oh, we did number 2.

  • Number 3, again from the Interphone Study.

  • We can discount that because we've now

  • read the conclusion of the study and looked

  • at a bit of the difference.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Number 4, "Harmful Association Between

  • Cell Phone Risk and Tumors."

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Let's see.

  • AUDIENCE: It says there's possible

  • AUDIENCE: Possible.

  • Studies providing a higher level of evidence

  • are needed [INAUDIBLE].

  • MICHAEL SHORT: Again, honest authors.

  • I applaud the authors for taking a controversial topic,

  • doing a fair bit of data, with at least enough metadata

  • analysis, I think the sample size is OK, and then saying,

  • higher level of evidence is needed.

  • What does the internet say?

  • It takes the one sentence that they

  • want to support their predetermined conclusion.

  • Very dishonest, if you ask me.

  • Number 5.

  • Oh, this is fun.

  • OK.

  • What does number 5 say?

  • AUDIENCE: Does this not just make you angry?

  • MICHAEL SHORT: Huh?

  • AUDIENCE: Does this not just make you angry?

  • MICHAEL SHORT: Yes it does make me angry.

  • This is why I'm showing it to you.

  • - infuriating, right?

  • But some of the comparisons between what

  • the folks on the internet will say with the sentence

  • that they want to say- and then you

  • go to the actual study, which they do

  • give you the link for, "a consistent pattern

  • of increased risk associated with wireless phones."

  • What does the study say?

  • Take a sec to parse this.

  • I'll make it a little bigger.

  • When you see an odds ratio of, let's say, greater than 1.

  • And see a confidence interval--

  • AUDIENCE: Oh, holy crap.

  • AUDIENCE: Oh!

  • [INAUDIBLE]

  • MICHAEL SHORT: Yeah.

  • Again, another odds ratio and another confidence interval.

  • Another odds ratio, another confidence interval.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Interesting.

  • The one interesting part is for what

  • they call ipsilateral cumulative use, which

  • means a tumor found on the same side of the head

  • as the cell phone, there is actually a confidence interval

  • that seems to be significant.

  • So, I'm not going to trash this study.

  • I'm going to say it's not quite conclusive.

  • It doesn't go out and say cell phones cause cancer,

  • despite this fellow coming out and saying

  • cell phones cause cancer.

  • OK, moving on to number 6, was a 404.

  • Let's just confirm.

  • Wasn't able to get it an hour ago.

  • Oh, it's back.

  • OK, let's see what it does.

  • I don't even know what this one's going to do.

  • AUDIENCE: [INAUDIBLE]

  • AUDIENCE: Potential [INAUDIBLE]

  • AUDIENCE: Possible association with [INAUDIBLE]

  • AUDIENCE: What's heavy mobile phone use?

  • MICHAEL SHORT: Heavy mobile phone use, yeah.

  • Well, they'll define that somewhere in the article.

  • So, some of these studies, it's like OK, there's

  • interesting viewpoints to be seen.

  • They shouldn't be ignored just because we

  • have this predetermined conclusion that cell

  • phones don't cause cancer.

  • It's important to go and actually look at the studies

  • and decide for yourself.

  • Let's get into the fun ones.

  • Number 7.

  • "A recent study on 790,000 middle aged women found that,

  • "women who used cell phones for ten or more years were

  • two-and-a-half times more likely," et cetera, et cetera.

  • "Their risk increased with the number of years

  • they used cell phones."

  • Let's look at the study.

  • OK, That's.

  • Not the study, so we need to go find the study.

  • And that's another news article about the study,

  • we need to go find this study.

  • Ah, finally.

  • AUDIENCE: The study.

  • MICHAEL SHORT: The study.

  • AUDIENCE: The study.

  • MICHAEL SHORT: Read the conclusion.

  • AUDIENCE: What the--

  • I'm so bad.

  • [LAUGHTER]

  • AUDIENCE: I don't think the people writing

  • these articles are actually like reading these--

  • MICHAEL SHORT: No, I don't think so either.

  • AUDIENCE: They just look at the title

  • and they're like, [INAUDIBLE]

  • MICHAEL SHORT: So, the best thing

  • that you can conclude about these sorts of people

  • is that they're not reading the studies and reporting on them.

  • If they are reading them and not getting it right,

  • no, not everyone can parse the science.

  • If they're reading them, understanding them, and cherry

  • picking the facts in order to support their conclusion,

  • that to me should be criminal.

  • We do live in a country where there's freedom of speech.

  • You're free to say whatever you want,

  • as long as it's not hate speech of various kinds.

  • It doesn't have to be right.

  • You also don't have to listen.

  • So just because you have freedom to talk,

  • doesn't mean people have an obligation to listen.

  • And this is the problem with a lot of this.

  • So I think my--

  • yeah, my notes for this study was just kind of the F word.

  • It was, how do you get the conclusion

  • from this internet article, which

  • wrote an article about an article

  • about an article about a study, when the conclusion says,

  • with an excellent sample size not associated.

  • OK.

  • We have like five or seven minutes left,

  • so let's skip ahead.

  • I had a fun one for number 12, cancer of the pituitary gland.

  • Let me get rid of the other stuff.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Oh, does that look

  • like a surprisingly familiar figure?

  • AUDIENCE: Cool.

  • MICHAEL SHORT: It's another article about the same study.

  • Let's just confirm.

  • AUDIENCE: [INAUDIBLE] articles about--

  • MICHAEL SHORT: Oh, look at that.

  • AUDIENCE: [INAUDIBLE] papers.

  • MICHAEL SHORT: That right there was the article written

  • about the study, where the other link was

  • an article, written about the article, written

  • about the study.

  • OK.

  • What else?

  • Next one.

  • Let's just keep going in number order.

  • Israeli study about thyroid cancer.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: OK.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: This appears to be a blog, so let's search

  • for the word "Israel."

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: OK, but first the news article.

  • So take a sec to parse some of this.

  • "The incidence of thyroid cancer has been increasing rapidly

  • in many countries, including the US, Canada, and Israel."

  • I mean, one thing to say-- let's say,

  • case control research on this topic is warranted.

  • Sure.

  • No one's going to refute a claim that, hey, maybe we should

  • study something properly, right?

  • Let's go a little further down.

  • Let's try to find the actual study.

  • Where is this study?

  • Interesting.

  • The main point of the study is that thyroid cancer and cell

  • phone usage are going up at the same time.

  • AUDIENCE: Wow!

  • MICHAEL SHORT: This is the point where

  • I like to say correlation does not imply causation, and hammer

  • that point home by going to one of my favorite blogs, Spurious

  • Correlations.

  • You can find any data set that correlates with any other data

  • set.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Let's look at some examples.

  • US spending on science, space, and technology

  • correlates with a 99.79% correlation of suicides

  • by hanging, strangulation, and suffocation.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Correlated, yes.

  • Causal, I don't think so.

  • [INTERPOSING VOICES]

  • MICHAEL SHORT: Yeah.

  • Divorce rate in Maine correlates with per capita consumption

  • of margarine.

  • AUDIENCE: [LAUGHTER] Michelle, [INAUDIBLE] margarine.

  • MICHAEL SHORT: You can find a link between anything

  • and anything else if you just search the data long enough

  • without searching for a mechanism or a reason.

  • AUDIENCE: That's cool.

  • Can we look at the age of Miss America below this?

  • MICHAEL SHORT: Oh, OK.

  • Age of Miss America correlates with murders

  • by steam, hot vapors.

  • [LAUGHTER]

  • AUDIENCE: [LAUGHTER]

  • MICHAEL SHORT: Clearly, we should ban the Miss America

  • pageant or make them older.

  • AUDIENCE: Yeah, [INAUDIBLE].

  • MICHAEL SHORT: Or the other way around, make them younger.

  • Maybe this is why we have toddlers in tiaras,

  • it's to stop murders by steam.

  • Oh, my God.

  • OK.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: So this is, again,

  • the point where you have to ask yourself,

  • what are the other confounding variables in this study?

  • Why else could thyroid cancer be going up?

  • Anyone?

  • I can probably come up with like a hundred

  • different possible reasons.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Any sort of other chemicals?

  • Let's say, more industrial runoff, more urbanization,

  • smog, inhalation, some amount, let's say, I don't know,

  • iodine released from Chernobyl making its way through.

  • Now, that would have had like a 30-day half-life.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Yeah, that's also got to pretty much decay

  • by now.

  • Yeah, there could be any number of reasons.

  • And just to say cell phones and thyroid cancer are correlated,

  • is like saying this.

  • What else?

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: This I think might actually

  • have something to--

  • AUDIENCE: [LAUGHTER]

  • MICHAEL SHORT: There might be a link here.

  • Revenue generated by arcades kids

  • with computer science doctorates.

  • Again, just a correlation.

  • AUDIENCE: [INAUDIBLE]

  • AUDIENCE: Sociology doctorates-- [LAUGHTER]

  • MICHAEL SHORT: Ah, look at the amazing--

  • it's got all the same humps.

  • And everything.

  • All right, I think I've made the point.

  • AUDIENCE: Actually, I like the margarine

  • and the divorce rate one

  • MICHAEL SHORT: Let's go on to some of the other studies,

  • let's say, number 15.

  • 11 of 29 cases of neuroepithelial tumors, cell

  • phone users accounted for 11 of them."

  • 11 of the 29 people in the study that got this type of tumor

  • used cell phones.

  • What's wrong here?

  • AUDIENCE: Who doesn't use cell phones?

  • People use cell phones.

  • Everybody uses cell phones.

  • They don't think about anything else that could have happened?

  • MICHAEL SHORT: No, no.

  • Here, I think the study is flawed.

  • What is the worst part about this study?

  • AUDIENCE: [INAUDIBLE]

  • AUDIENCE: It's only 29 cases.

  • AUDIENCE: It's 29 cases.

  • MICHAEL SHORT: 29 cases, sample size.

  • If you get 11 out of 29 and say half of the tumors

  • we saw were attributed to cell phones, that

  • is not a proper conclusion.

  • AUDIENCE: How are you going to [INAUDIBLE] it

  • to a cell phone [INAUDIBLE]?

  • MICHAEL SHORT: Let's see, number 17.

  • Ah, OK.

  • Another Israeli study that talked

  • about parotid gland cancers and salivary gland cancers.

  • My note to this is read the last sentence.

  • AUDIENCE: [LAUGHTER] [INAUDIBLE]

  • AUDIENCE: Like, I'm sure there's other factors [INAUDIBLE]

  • [INTERPOSING VOICES]

  • AUDIENCE: They cause cancer.

  • MICHAEL SHORT: The blog says, cause cancer.

  • The data says, no causal association.

  • So again, almost criminally ignorant.

  • How many times did you have to miss

  • the last sentence, the conclusion of the article,

  • to pick the part that you want?

  • AUDIENCE: But everything you read on the internet is true.

  • You know, it's [? illegal. ?]

  • MICHAEL SHORT: All I can say is everything

  • that you read on the internet was written.

  • That's the best I can say.

  • Number 20, we don't even have to go to the study here.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Oh, boy.

  • AUDIENCE: [INAUDIBLE] machine learning [INAUDIBLE]..

  • MICHAEL SHORT: Let's check the study to make sure

  • that the quote is actually correct, but before--

  • AUDIENCE: [INAUDIBLE] Oh, my God.

  • MICHAEL SHORT: Four women.

  • AUDIENCE: It's just the one.

  • AUDIENCE: Study four women.

  • Looks like it might [INAUDIBLE]

  • MICHAEL SHORT: Yeah, by the prestigious publication,

  • Hindawi, which sends me more emails

  • than I read their articles.

  • So let's look at the abstract.

  • Of all four cases, they are a case studies,

  • so striking similarity, how hard do

  • you think it would be to find four women with a certain type

  • of breast tumor?

  • There's a lot of women in the world, right?

  • AUDIENCE: Yes.

  • MICHAEL SHORT: And breast cancer is one of the leading

  • causes of cancer in women.

  • It wouldn't be hard to cherry pick four people to get

  • the same conclusion you want.

  • Oh, and there's another correlation,

  • out of 108 billion humans that have ever lived and have

  • been exposed to ionizing radiation, all of them

  • died at some point.

  • AUDIENCE: [LAUGHTER] At some point.

  • MICHAEL SHORT: At some point, yeah.

  • every human that's ever lived has died.

  • And every human that's ever lived

  • had been exposed to ionizing radiation.

  • AUDIENCE: [INAUDIBLE]

  • AUDIENCE: It must be true.

  • [INAUDIBLE]

  • MICHAEL SHORT: Perfect correlation, no causation.

  • Let's see, two more.

  • I think we have time for two more.

  • This is kind of fun.

  • An eye cancer study.

  • All right, let's just go--

  • "found elevated risk for exposure

  • to radio frequency transmitting devices."

  • AUDIENCE: Are these real studies?

  • Don't the authors get mad that people

  • are using their studies wrong?

  • MICHAEL SHORT: I'm sure the authors do get mad,

  • but what are you going to do about some person

  • on the internet, right?

  • You can send a nasty letter to the magazine, which

  • might reject it as hate mail.

  • OK, on the blog.

  • AUDIENCE: [INAUDIBLE] very strong--

  • MICHAEL SHORT: What does it say?

  • Elevated risk for exposure in the study.

  • AUDIENCE: People only get excited by some crazy person.

  • AUDIENCE: [INAUDIBLE] it's about.

  • [INAUDIBLE]

  • MICHAEL SHORT: I don't think I have to make my point anymore.

  • We've gone through about half of them.

  • I encourage the rest of you guys to go through the other half.

  • And to the people, like this Lloyd Burrell,

  • I say check your facts.

  • What you're doing is criminally incompetent.

  • With the way that people are misleading the public

  • to get whatever pre-gone conclusions that they have

  • from their emotions or their funding sources

  • or whatever the reason to be, by misquoting facts

  • you're absolutely misleading people

  • and spreading false science.

  • Because, to me, the most exciting moments in science

  • don't end with the words, "I told you so,"

  • but start with the words, "that's interesting."

  • So just because the studies that you find

  • don't support your predetermined conclusions,

  • doesn't mean you should reject them.

  • It means that you might have to change your idea.

  • So, on that note, I'd like to stop here.

  • We'll come back on Thursday and go over

  • the short and long-term biological effects of radiation

  • and look at some more garbage science.

  • Yeah?

  • AUDIENCE: How do you feel about those wireless chargers

  • they have now?

  • It's like a conductive charger so it

  • uses like a low-branch, strongish magnetic field.

  • MICHAEL SHORT: Mm-hmm.

  • AUDIENCE: And people are like, oh, my God.

  • That's so scary.

  • MICHAEL SHORT: I would just say go to the studies.

  • It's very easy to say put a bunch of rats on a cell phone

  • charger, turn it on, and see what happens.

  • I mean, the data doesn't lie.

  • The reason might be a little hard to figure out.

  • Yeah.

  • Yeah.

  • So, I mean, another thing is, when

  • people have a predetermined--

  • I know it's a little past 10:00, but no one's

  • gotten up so I'll keep ranting.

  • So a lot of this neo-environmentalism going on

  • has the predetermined conclusion that only sources

  • of power light on the Earth, like solar and wind, that

  • are renewable and such, are the ways to go.

  • And immediately dismiss nuclear as not part

  • of the environmental solution, despite being part

  • of the environmental solution.

  • A large source of power that's very efficient

  • and doesn't admit any CO2.

  • It might surprise them to know that manufacturing wind

  • turbines is a major source of radioactivity.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: Anyone want to guess where?

  • AUDIENCE: Rare-earth magnets.

  • MICHAEL SHORT: Yes, thank you, rare-earth magnets.

  • The major cause of wind turbine failure in the last decade

  • has been the gearboxes breaking down.

  • Because in order to extract power,

  • you have to gear down those giant turbines by quite a bit.

  • And those gears, 300-feet up in the air, tend to break down,

  • they're hard to maintain.

  • How do you fix it?

  • Make stronger magnets.

  • Put in rare-earth magnets that electromagnetically harvest

  • the energy, instead of gearing it down and doing the same

  • and you don't have mechanical things grinding.

  • What are rare-earth magnets made out of?

  • AUDIENCE: Rare-earths.

  • MICHAEL SHORT: Rare-earths.

  • Lanthanides, which happen to be found with actinides,

  • thorium,r whatever actinium exists, radium, uranium,

  • things with similar chemistry.

  • What do you do when you extract the rare-earths that you

  • need from the rare-earth ore?

  • You ditch the remains, which are concentrated sources

  • of these radioactive byproducts.

  • Where do most radioactive--

  • I'm sorry, where do most rare-earth magnets come from?

  • AUDIENCE: China.

  • MICHAEL SHORT: China.

  • How is China's record on environmental practices?

  • AUDIENCE: Not [INAUDIBLE].

  • [INAUDIBLE]

  • [INTERPOSING VOICES]

  • MICHAEL SHORT: Spotty, at best.

  • AUDIENCE: Questionable.

  • MICHAEL SHORT: Yeah.

  • So, again, one of those things where people say,

  • oh, wind power has absolutely no effect on the environment.

  • Check the radioactivity of making windmills.

  • AUDIENCE: I want you to tell the Sierra.

  • MICHAEL SHORT: I don't know if the Sierra Club would listen.

  • AUDIENCE: [INAUDIBLE]

  • MICHAEL SHORT: I have heard murmurs or rumors

  • of them coming around to the idea of nuclear power.

  • There's an article that said they switched positions,

  • then there was a counter article, followed a day later,

  • that says, no, that was a rogue actor.

  • They don't reflect the views of the Sierra Club.

  • The problem is with all these neo-envrionmentalists

  • and cell-phones-cause-cancer people

  • and food-irradiation-is-evil people,

  • you'll find them cherry picking data to support the conclusion

  • that they already felt they wanted.

  • And when confronted with overwhelming evidence

  • to the contrary.

  • They don't change their view.

  • And that to me is the best thing about science.

  • If you prove to me that you're wrong,

  • I will say, thank you, not [INAUDIBLE]..

  • AUDIENCE: [LAUGHTER]

  • MICHAEL SHORT: So, there you go.

  • All right, I'll see you guys on Tuesday.

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