Would wearing sunscreen help during a nuclear disaster/attack?

[MELJA]

TL;DR Summary

The purpose of sunscreen is to block UV rays, right? Would it work against alpha particles as well?

So as I understand it, there are five types of radiation: alpha particles, beta particles, sub-red light, visible light, and above-violet light. Sub-red light is basically like Superman's heat vision, while above-violet light includes UV light like the UV-A and UV-B that sunscreen protects you from, X-rays, gamma rays, and cosmic rays (the last of which I don't think human-made weapons produce).

Since the whole purpose of sunscreen is to protect you from UV-A and UV-B rays, would that work against a nuclear disaster as well? I know that those aren't really the most dangerous part of the above-violet radiation, since X-rays and gamma rays probably create higher cancer risk and can also penetrate through objects to a much greater degree, but it would help against that part of the spectrum, right?

I also suppose sunscreen would help create a tiny barrier between your skin and any dust that contained radioactive isotopes, if traces of the radiation-emitting material itself got on you rather than just the radiation. Though in that case, a bigger concern might be to avoid inhalation, and then to wash it off you.

Also, I've heard that a sheet of paper can block alpha particles. Could sunscreen block them as well? If so, would they become "stuck" in the sunscreen? Would they remain dangerous?

 

[Astronuc]

TL;DR Summary: The purpose of sunscreen is to block UV rays, right? Would it work against alpha particles as well?

So as I understand it, there are five types of radiation: alpha particles, beta particles, sub-red light, visible light, and above-violet light. Sub-red light is basically like Superman's heat vision, while above-violet light includes UV light like the UV-A and UV-B that sunscreen protects you from, X-rays, gamma rays, and cosmic rays (the last of which I don't think human-made weapons produce).

We commonly talk of alpha particles, which are emitted by nuclei heavier than bismuth, beta particles (high energy electrons from nuclei) and photons (gamma rays and X-rays). With respect to gammas and X-rays, the distinction is the origin, nuclear in the case of gammas, and atomic (orbital electrons) in the case of X-rays. There is bremsstrahlung radiation, in which a photon is emitted by an accelerated electron under the influence of a nuclear electric field. I have seen some refer to bremsstrahlung photons as X-rays, while other use gamma rays. Cosmic rays are not produces by fission devices. Rather, besides the kinetic energy of the fission products, and process produces copious amounts of beta particles, gamma rays (about 7 or 8 per fission, as well as at least 2 following beta decay of fission products), X-rays, UV, visible light and infrared.

Alpha particles may be found in some transuranic elements which are produced by successive neutron capture and beta decay of uranium atoms. Alpha particles do not travel far. Betas are more penetrating, as are X-rays and gamma rays; the greater the energy, the more penetrating.

Also, I've heard that a sheet of paper can block alpha particles. Could sunscreen block them as well? If so, would they become "stuck" in the sunscreen? Would they remain dangerous?

To determine the effectiveness of sunscreen, one would need to review the reflectance as a function of photon energy. Beyond UV, they would not be particularly effective. Clear sunscreen might be effective for UV, but not visible, while the ZnO or TiO₂ cream would be effective for UV and some visible light. A layer would absorb some alpha particles.

Alpha particles neutralize to for helium-4 atoms, so that is essentially harmless, unless there is enough to displace air/oxygen. Otherwise, it is the slowing down process (by any radiation) that produces harmful effects.

Most fission products emit beta particles, and it is the beta, X-ray and gamma radiations, especially from those radionuclides that are inhaled (into lungs) or ingested (taken into the body with food/water) that are most concerning. Radionuclides of I are a concern since they likely end up in the thyroid gland, while Cs is chemically similar to Na and K, so affects systems using those elements, and Sr and Ba are chemically similar to Ca, so it would tend to go to the bones, or taken into the alimentary system.

 

[mathman]

The most dangerous radiation from a nuclear disaster are gamma rays and neutrons. Sunscreen would have no effect on stopping these.

 

[Vanadium 50]

First, the sunscreen will evaporate.
Then you will.

 

[Rive]

Sub-red light is basically like Superman's heat vision

That 'sub-red' carries around third of the released energy and is the main cause of burns and damages on people around. UV radiation is considered intense, but short: the flash may cause temporary blindness or sunburn-like effects relative far away, but the most widespread immediate damage comes from heat (radiation).
Even gamma radiation will be more constricted.

As I recall, the Japanese imperial army started to use some white bed-sheet like overclothing to limit the effect of heat radiation after the first bomb, as a countermeasure. Survivors of the bombs also showed strong protective effect of clothing.
Sunscreen as a protective layer is not effective against heat (radiation) and in general, it is just not in par with clothing, but far more inconvenient to wear on long term.

I've found some mentions about Edward Teller applying sunscreen before the Trinity test, though.
Guess they got enough data to drop the idea later on.

 

[bob012345]

First, the sunscreen will evaporate.
Then you will.

Indeed. So says Sarah Connor from Terminator 2;

 

[artis]

@MELJA You don't need sunscreen to block alpha particles, as long as the source is outside your body they are blocked by your skin just fine.

 

[pinball1970]

@MELJA You don't need sunscreen to block alpha particles, as long as the source is outside your body they are blocked by your skin just fine.

Just the fireball /blast to deal with



10.55 the narrator explains that after the fireball the blast follows that would throw people against buildings.

"arm and leg fractures are likely,"

Whitewashing the windows at 13.10 to keep some of the heat out.

So your are not fried to death before the house is obliterated.

 

[DaveC426913]

First, the sunscreen will evaporate.
Then you will.

So you're saying it'll buy me a little time...

 

[anorlunda]

For most of my life, we had to live with the assumption that nuclear war meant the end of all life on Earth. See the movie, "On the Beach", and Nuclear Winter. That may not be a true, but it is a good working assumption. If that's true, who cares about ways to live a few days longer?

 

[artis]

For most of my life, we had to live with the assumption that nuclear war meant the end of all life on Earth. See the movie, "On the Beach", and Nuclear Winter. That may not be a true, but it is a good working assumption. If that's true, who cares about ways to live a few days longer?

With modern filtration systems and big enough food storage for long enough , technically someone having access to such a bunker given it doesn't experience a direct hit could survive for say a few years in it.
First few years I suppose would be the hardest , after that stuff would settle slowly and the short lived highly radioactive radionucles decay away so much so that one could walk around and get some sun.I haven't done the math nor do I know anyone who has done it or whether it is even possible but if I had to guess, I doubt that by having a nuclear war we could get radiation levels on average around the world higher than those that were present within the Chernobyl reactor zone and immediate vicinity.
And while many got cancers down the road and various health effects many also survived being in that zone and breathing in every radionuclide known to man.

Maybe I'm wrong but that is my assessment based on what I know

And how dirty can a modern nuke be? IIRC an average two stage H bomb uses about few hundred kg's of "fuel" , the RBMK at chernobyl had about 200 tons of irradiated U fuel alone not to count the irradiated graphite and other stuff.
So in terms of dirtiness , about 200 modern bomb equivalent? I guess @Astronuc will be able to better estimate

 

[bob012345]

For most of my life, we had to live with the assumption that nuclear war meant the end of all life on Earth. See the movie, "On the Beach", and Nuclear Winter. That may not be a true, but it is a good working assumption. If that's true, who cares about ways to live a few days longer?

If Russia decides to use nuclear weapons in Ukraine it won't likely be the end of the world but the inflation and disruptions we had from the pandemic will seem insignificant in comparison in my view.

 

[anorlunda]

I doubt that by having a nuclear war we could get radiation levels on average around the world higher than those that were present within the Chernobyl reactor zone and immediate vicinity.

We are working with very different assumptions. I'm talking about escalation to full scale war, resulting in maybe 10K thermonuclear explosions. So, 10³ to 10⁴ as much radiation as Chernobyl. But a single tactical warhead in Ukraine with no retaliation is maybe only 10^-5 times as much as a full scale war.

Nuclear brinksmanship is a scary topic. Many great minds have wrestled with the issues for the past 70 years. The only safe conclusion is to never allow the first one to be used.

 

[DaveC426913]

Many great minds have wrestled with the issues

And not all of those minds were biological...

The only safe conclusion is to never allow the first one to be used.

 

[bob012345]

For most of my life, we had to live with the assumption that nuclear war meant the end of all life on Earth. See the movie, "On the Beach", and Nuclear Winter. That may not be a true, but it is a good working assumption. If that's true, who cares about ways to live a few days longer?

There was a 1984 movie called Threads which suggests civilization would not end completely but be rather medieval. The title suggests civilization hanging on by a mere threads. Here is the official trailer;

 

[anorlunda]

I don't want to hijack this thread. But if someone else wants to start a GD thread on the survivability of nuclear war, I'll participate.

 

[bob012345]

So you're saying it'll buy me a little time...

Assuming a sunscreen density ~$1 \frac{ g}{mL}$ and a sunscreen layer ~ $1 \frac{mg}{cm^2}$ the layer thickness is ~10 microns, this would be sub-picosecond but assuming one would apply it ~10x thicker for a nuclear war, perhaps a picosecond or two. Just remember to Duck and Cover.