[HN Gopher] Why is my dryer radioactive?
___________________________________________________________________
Why is my dryer radioactive?
Author : jpitz
Score : 341 points
Date : 2023-05-18 16:58 UTC (6 hours ago)
(HTM) web link (physics.stackexchange.com)
(TXT) w3m dump (physics.stackexchange.com)
| kzrdude wrote:
| I haven't read much on physics before. My favourite thing to do
| on these stack overflow sites (or on specific tags) is to go to
| Questions -> sort by score, and just read through the top
| questions and answers. It's a bit hidden away because they want
| to steer people to the active questions, not to established ones.
| kzrdude wrote:
| I'll just make a note of a few good ones..
|
| https://physics.stackexchange.com/questions/121830/does-eart...
| There is no tidal bulge
| belter wrote:
| GPT-4 get's this wrong...There is still hope for humans...
| robocat wrote:
| At least lay the blame correctly: humans get this wrong and
| they write it all over the internet and we then train our
| models on incorrect information.
|
| An astonishing amount of what we each believe is plain
| wrong, especially when we have little stories about it.
| Jun8 wrote:
| The tidal bulge one is one my all time favorites, you should
| absolutely read the answer. tl;dr the simplistic view of two
| tidal bulges (that started with Newton) is wrong! This is one
| of those physics simplifications that still gets pushed
| around. For another example, see speed of light in glass is
| slower than vacuum.
| mparnisari wrote:
| > they want to steer people to the active questions
|
| why?
| voynich wrote:
| I always find this a more entertaining way to learn about these
| topics, because they're questions which we might have had
| before, but never thought much about.
| dylan604 wrote:
| Yeah, these kinds of things are what the internet should be all
| about rather than whatever the hell it morphed into. Sure, I'm
| applying my morals and expectations to it, but I don't think
| I've ventured onto a thin limb here.
| t0bia_s wrote:
| The true story part is hilarious!
| ck2 wrote:
| Florida is about to build some test roads using phosphogypsum, a
| radioactive waste product of the fertilizer industry that has
| been piling up and they want to unload.
|
| It contains high quantities of radium which decays into radon,
| this should end well.
|
| > "Phosphogypsum contains appreciable quantities of uranium and
| its decay products, such as radium-226," according to the EPA.
| And because the fertilizer production process concentrates waste
| material, "phosphogypsum is more radioactive than the original
| phosphate rock," the agency notes.
|
| > "The radium is of particular concern because it decays to form
| radon, a cancer-causing, radioactive gas," the EPA adds.
|
| https://www.npr.org/2023/05/09/1174789570/florida-roads-radi...
| skybrian wrote:
| It's outside though, so the radon wouldn't normally accumulate
| unless something weird happens. Seems like this is the sort of
| thing you'd want experts to look at.
| ck2 wrote:
| They have looked. For 30 years. And it was continuously
| banned. Until the previous president decided all regulation
| was silly and unprofitable.
|
| Now we have states trying to override federal regulations
| because superpac donations.
| skybrian wrote:
| Who is "they?" What did they find?
| bobthepanda wrote:
| It is a road, though, and we know all sorts of things already
| accumulate via stormwater runoff.
| hammock wrote:
| >It's outside though, so the radon wouldn't normally
| accumulate
|
| Well, no more than any other heavier-than-air gas, like say,
| fog.
| westmeal wrote:
| What the hell...
| sbierwagen wrote:
| Uh oh, nobody tell NPR about granite countertops.
| gwbennett wrote:
| Great point and made me laugh!
| r3trohack3r wrote:
| We had this issue in the Midwest (central Illinois). Can't
| remember exactly why, but radon would accumulate in the
| basements. Had to have sensors and ventilation for it.
| anamexis wrote:
| Indeed - radon checks are a standard part of pre-purchase home
| inspections, because remediation can be quite expensive
| Kon-Peki wrote:
| Most of the cost is the installation of equipment in the
| existing home. In areas of the country that have a lot of
| radon, it's not uncommon to install the equipment during
| construction of the house foundation, which then only adds a
| few hundred dollars to the total cost.
|
| > Radon-resistant new construction (RRNC) typically costs a
| builder between $250 and $750. RRNC could cost less than $250
| if the builder already uses some of the same techniques for
| moisture control.
|
| https://www.epa.gov/radon/radon-resistant-new-
| construction-h...
| hinkley wrote:
| Not uncommon as in it's building code in those areas.
|
| Tricky bit I think is when you live in a state with small
| pockets of radon instead of broad regions. Then you're back
| into crapshoot territory.
| danbtl wrote:
| We had such a remediation done recently, in Alberta close to
| the rocky mountains.
|
| Costs were around $2,000 CAD to install a sub-slab
| depressurization system (i.e. a fan that pulls air from below
| the house and vents it away from the house).
|
| Radon values dropped from around 500 Bq/m3 to less than 20
| Bq/m3.
| hinkley wrote:
| Those systems must be new. The classic solution is to
| install drain pipes before pouring the slab, so one can
| imagine how difficult it would be using 1980's construction
| techniques to retroactively add piping below a finished
| house.
|
| We also had to dig trenches to lay natural gas lines, but
| we have a way to do those with horizontal boring techniques
| (of course then people who didn't know what they were doing
| put them straight through sewer lines, causing backups,
| visits from the Roto Rooter man, and subsequent explosions
| due to dumping natural gas straight into the sewer main).
|
| Is it safe to assume they're using something like that with
| perforated pipes to exhaust radon?
| ilyt wrote:
| >Those systems must be new. The classic solution is to
| install drain pipes before pouring the slab, so one can
| imagine how difficult it would be using 1980's
| construction techniques to retroactively add piping below
| a finished house.
|
| They didn't had diggers and drills in the 80's ?
| inglor_cz wrote:
| Some places in Czechia have a huge problem with radon emanating
| from the ancient bedrock below. These places, even though rural
| and not polluted, tend to have more deaths from lung cancer
| than the rust belt in northern Moravia, where air quality in
| general is worse, but the radon problem is almost non-existent.
|
| Newly built houses are required to be radon-proofed, AFAIK.
| theGnuMe wrote:
| Happens almost everywhere where basements exist.
| lazide wrote:
| Higher amounts of granite in the soil make it worse.
| Depending on the area, it can be a severe health hazard to
| the point no one puts in basements - others, kinda meh.
|
| Here is a map! [https://www.epa.gov/sites/default/files/2018-
| 12/documents/ra...]
| bhhaskin wrote:
| Same issue in Northern Nevada. Radon gas seeps in.
| dmicah wrote:
| It can be an issue everywhere, Radon is the second leading
| cause of lung cancer, after smoking.
| schiffern wrote:
| This claim (which ultimately came from the EPA) is suspect at
| best. It just comes from _assuming_ a Linear No-Threshold
| model, which flatly contradicts the available body of medical
| evidence.
|
| https://youtu.be/TYZglUjLE0Y
| pfdietz wrote:
| Indeed, it's good to be cautious of such claims. Low level
| radiation could be worse than predicted by the LNT.
| joshuahedlund wrote:
| Thanks for posting this, I will check it out. As a
| Midwesterner with a basement I had once looked into those
| claims about radon as the second-highest cause of lung
| cancer with concern and found the evidence much weaker than
| I expected. Even by EPA estimates[0] almost 90% of the lung
| cancer deaths attributed to radon are smokers (i.e. who
| have already weakened lungs), and there didn't seem to be
| good evidence of damage from basement radon for non-
| smokers.
|
| [0]https://www.epa.gov/radon/health-risk-radon
| schiffern wrote:
| Let me preemptively disclaim that I do have nitpicks
| about the talk I linked, but IMO his main argument is
| sound.
|
| In particular I think his scientific explanations aren't
| always fully accurate, and he worries about measurement
| minutia very strenuously. Also at one point he says you
| could breathe 80% radon/20% oxygen, which while
| chemically this is true, radiologically it would be
| suicidal.
|
| Those nitpicks aside, his point about the EPA LNT model
| having no clothes is spot on. After "the scales fell from
| my eyes," now I can't _not_ notice how all those same
| Party Line Claims get parroted in every piece of radon-
| related content.
|
| Another glimpse down the rabbit hole is this interview
| with the late Dr Bernie Cohen, who studied the link
| between residential radon and cancer:
|
| https://youtu.be/xhkBLhw-8pk
| pfdietz wrote:
| The alternative to LNT is to conservatively assume
| radiation has the maximum effect not ruled out by
| evidence (after all, radiation is not a criminal
| defendant that's innocent until proven guilty). This
| would make low level radiation more dangerous than
| predicted by LNT, not less.
| geoduck14 wrote:
| I'm in the middle of moving from Texas to New England. In
| Texas, Radon is such a "not a problem", that I've _never_
| considered it before our move. In New England, our basement
| tested above the "safe" limit (iirc, 4 somethings), so we
| are having a venterlator installed for ~$1.4k.
|
| In the south, Radon "can" be an issue, but it _simply isn 't_
| an issue. In New England, it is _often_ an issue.
| Merad wrote:
| > In the south, Radon "can" be an issue, but it simply
| isn't an issue.
|
| There's more to the south than Texas, y'know. I can't
| recall if radon tests are required during a home inspection
| here in NC, or just highly recommended, but when I was
| buying a house last year I toured several homes that had
| radon mitigation systems installed.
| NotYourLawyer wrote:
| Nobody in Texas has basements.
| __MatrixMan__ wrote:
| Heavy metals in the nearby earth are the obvious parameter
| here--you need something to decay into radon for there to
| be radon.
|
| But I think another factor has to do with the water table.
| In some places the water table rises high enough to flood
| basements, so you don't usually have basements at all in
| those places, and subsequently you don't have large
| reservoirs of radon adjacent to living spaces. I know of
| some people here in CO (where we have decaying granite in
| the soil) that don't have a basement and still need a radon
| ventilator, but it's not very common.
| simcop2387 wrote:
| My understanding on why this is, is because in New England
| there's a lot more granite in the ground. Granite is
| particularly annoying in that respect because the trace
| amounts of, i think, uranium and radium that the rock
| concentrated when it was formed will give off the radon gas
| when they decay.
| eichin wrote:
| and that can mean high _outdoor_ radon levels... a home
| inspector back in early 2000 told me about a seller
| sneaking back in and opening basement windows to attempt
| to pass a radon test (sensors left in the basement over
| the weekend.) The inspector caught it but let the test
| run to completion - at which point it failed _anyway_
| because the adjacent "forest with exposed granite rocks"
| was a fine natural radon source...
| xenadu02 wrote:
| Because the rock formations in some areas are more prone to
| production of Radon gas which slowly diffuses through the soil.
| Basements in those areas tend to have Radon infiltration. It is
| obviously very slow but the basement is a low point and often
| not well ventilated which can allow the Radon to accumulate.
|
| Poured slabs are less permeable, not a low point, and tend to
| have better ventilation either intentionally or
| unintentionally.
| lsllc wrote:
| Clearly it's residual radiation from the collapse of the wormhole
| to the sock dimension.
|
| /s
| crazygringo wrote:
| We can confirm this hypothesis if there's also radiation in
| between the couch cushions from the wormhole to the dimension
| of lost pocket change...
| perihelions wrote:
| I doubt it has anything to do with molecular dipoles. More likely
| I'd guess ionized radionuclides adsorb onto macroscopic dust
| particles (or some similar mechanism), which then maintain a net
| charge imbalance.
| jpmattia wrote:
| Yeah, the wording in the explanation was particular suspect:
|
| > _Polarized or polarizable objects are attracted to strong
| electric fields_
|
| Polarizable objects _align_ in an E field, they aren 't
| _attracted_ to the E field. I don 't doubt you could contrive a
| field to move a polarized object, but the wording seems to be
| confusing an ionized object with a polarized object.
| _Microft wrote:
| Polarized objects in inhomogeneous electric fields experience
| a net force. The effect is called dielectrophoresis.
|
| https://en.wikipedia.org/wiki/Dielectrophoresis
| [deleted]
| afterburner wrote:
| > I was once prevented from leaving a neutron-science facility at
| Los Alamos after the seat of my pants set off a radiation alarm
| on exit. This was odd because the neutron beam had been off for
| weeks. It was a Saturday, so the radiation safety technician on
| call didn't arrive for half an hour -- at which point I was
| clean, so the detective questions began. I had spent the day
| sitting on a plastic step stool. The tech looked at it, said that
| radon's decay products are concentrated by static electricity,
| and told me that I needed to get a real chair.
|
| Hilarious
| thedanbob wrote:
| I appreciated his tl;dr in the comments:
|
| > ONE TIME I GOT RADON ON MY BUTT
| eastbound wrote:
| > I had spent the day sitting on a plastic step stool
|
| So, if it attracts radon, does it raise the risk profile of the
| person? Should I ban sitting on static-electricity objects in
| radon-sensitive areas?
| duskwuff wrote:
| Not really. If there's that much radon in the air, it's a
| risk to health with or without the static electricity.
|
| (Los Alamos doesn't have dangerous concentrations of radon;
| they just have very sensitive detectors.)
| yummypaint wrote:
| They also make you take off synthetic jackets for the same
| reason. Apparently alot of people have had to do extra
| paperwork over the years because of their patagonia grabbing
| radon.
| dylan604 wrote:
| I know that red tape is a thing with gov't procurement, but
| come on!
| tpmx wrote:
| Also: That competence (the radiation safety technician).
| bitL wrote:
| I presume that the technician had at least one PhD. I had a
| colleague who worked at Los Alamos with a top PhD and he was
| basically driving around placing and collecting data from
| some sensors all day long.
| dylan604 wrote:
| I would hope that at some place like Los Alamos the
| technicians are a little more qualified than your run of the
| mill techs.
| tpmx wrote:
| I suppose the downside of all that secrecy is balanced with
| the upside of having lots of competent and smart
| colleagues.
|
| In my experience that is worth even more than a very high
| salary for your quality of life.
|
| (That _1958_ article morkalork dug up and presented below,
| seems historically interesting at least. Thanks for making
| an effort to show it.)
| morkalork wrote:
| You might lose your mind a bit if you're surrounded by
| them 247 though.
|
| >Although the town is trim and neat, With cozy houses on
| every street, Though saying so is indiscreet,
|
| >I hate it.
|
| From: https://web.archive.org/web/20201126185123/https://
| archive.m...
| roywiggins wrote:
| You'd hope so, but...
|
| https://www.science.org/content/article/near-disaster-
| federa...
| jupp0r wrote:
| Do you think they would be paid more?
| zamnos wrote:
| Nope. Government salaries are public information, and are
| reported all over the usual sites (levels.fyi, glassdoor,
| indeed, etc) More importantly though, the government
| doesn't give out stock options with a vesting schedule.
| Meanwhile, techs who were at Tesla and got a small grant
| when it was at $20 are likely pretty happy with the stock
| being at $170. (Tech's that got grants at $400, less so.)
| Eumenes wrote:
| National labs have alot of smart people, but alot of paper
| pushers too
| [deleted]
| dotBen wrote:
| Related: HNer recommendations for home geiger counters? (serious
| request - for general fun/experimentation/curiosity satiation)
| shmerl wrote:
| [dead]
| schiffern wrote:
| I've seen Cody (of CodysLab fame/infamy) use a GMC-320 Plus,[0]
| which runs about $130.
|
| You can get the GMC-300E a bit cheaper, but with no temperature
| compensation sensor[1] it won't be quite as accurate.
|
| [0]
| https://old.reddit.com/r/codyslab/comments/hk3jru/more_fun_w...
|
| [1]
| https://www.gqelectronicsllc.com/support/GMC_Selection_Guide...
| sbierwagen wrote:
| GQ makes several dosimeters, I own the dual-tube GMC-500+.
|
| The cheaper single tube dosimeters will max out and saturate at
| radiation levels far below those that are immediately harmful
| to human health. (This was the source of the famous "3.6
| roentgen per hour, not great, not terrible" meme-- he was
| looking at a meter that was reading off-scale high at 0.001
| R/s)
|
| If you're buying a dosimeter with the threat in nuclear war in
| mind, check the specs for maximum readings.
| robocat wrote:
| > "3.6 roentgen per hour, not great, not terrible" meme
|
| Quote from HBO's Chernobyl, the _dramatisization_ of Anatoly
| Dyatlov: https://knowyourmeme.com/memes/anatoly-dyatlov
|
| A more balanced view of him:
| https://www.rbth.com/history/330525-anatoly-dyatlov-
| chernoby... and https://www.history.com/news/chernobyl-
| nuclear-disaster-7-pe...
|
| Aside: all of us, even the most competent engineers, can deny
| what is happening or make bad calls during an emergency,
| especially where everything is unknown during the initial
| stages. It takes very good training to teach us to make
| better emergency decisions - e.g. firefighter's training, and
| some military. Beware of selection bias in repeated deadly
| situations.
| rolobio wrote:
| I have a GQ 600-RPS and I love it. It detects alpha, beta and
| gamma. Detection range is only a few inches, so you have to
| know what to look for. We take it on family outings and search
| for uranium rocks.
| blackfawn wrote:
| I really like my https://www.bettergeiger.com/ (no affiliation
| with them, I just own one and am happy with it) It uses a
| solid-state scintillator instead of the older and less
| sensitive Geiger-Muller tube.
| BetterGeiger wrote:
| Thanks :D
| jboy55 wrote:
| I have a GMC-320S, its ok, I had to cut away some of the
| plastic so it could read a uranium source I bought. The plastic
| housing would shield the tube from most of the radiation of the
| source. There are little slits that would let some in, I just
| widened them with a dremel.
|
| I wouldn't recommend it again, but if you received one as a
| gift, with a bit of tweaking, you'll be measuring random stuff
| in your house.
| throwawaymaths wrote:
| Beta decay energies can be as low as 10ish KeV and static
| discharge can be in the 10 KV range, is it possible there's just
| crosstalk?
| cwmma wrote:
| Reminds me of the story about how Radon was discovered (well the
| fact that it can accumulate in homes). The story goes that a
| worker at a nuclear power plant kept on setting off the detectors
| when coming in to work and eventually they investigated his
| house.
| robmiller wrote:
| The nuclear power plant had built the homes to house workers in
| the early 1980s and to an early form of Energy Star compliance,
| with an emphasis on being air-tight. Radon was trapped in these
| homes, workers set off the alarms, and the radon mitigation
| industry was born.
| taubek wrote:
| I saw this nice visualization of radon decay time at
| https://www.reddit.com/r/dataisbeautiful/comments/13fw2uh/oc...
| jeffrallen wrote:
| That guy got out by the seat of his pants!
| BetterGeiger wrote:
| I think the core of the explanation given is correct but some of
| the adjacent details need adjustment. The important part is:
|
| "Clothes dryers are very effective at making statically charged
| surfaces. (Dryer sheets help.) So when radon and its temporary
| decay products are blown through the dryer, electrically-
| polarized molecules tend to be attracted to the charged surfaces"
|
| What that commenter misses is that nearly all hobbyist grade
| detectors (Geiger tubes) are not sensitive to alpha but they are
| highly sensitive to beta and a little sensitivity to gamma.
| However, any thin solid will block beta, so they would need the
| Geiger tube to be very near the radiation emitting material to
| pick up the beta. In other words, if they're just waving the
| detector around they're probably just catching the gamma.
|
| The radon in the air decays into various progeny, and by the time
| it reaches the dryer that will be to some extent in equilibrium,
| so several isotopes, including gamma emitters, will be present in
| the mix. Therefore I'm not surprised the detector reads a tiny
| bit of that.
|
| Why it dissipates is probably not a decay thing but rather the
| accumulated material gradually diffusing away from the filter or
| whatever after the dryer is turned off and no longer actively
| accumulating radon.
|
| This could be tested by putting a detector right next to the
| filter to see how much beta it picks up. I've basically done that
| with a home air filter:
|
| https://twitter.com/BetterGeiger/status/1605639346865901570?...
|
| That's with the detector I make and sell which is primarily
| sensitive to gamma, which is why I could register a reading
| through the plastic container, even a couple days after preparing
| the test. When I used a pancake style detector sensitive to alpha
| and beta, directly against the exposed filter, the detector
| reacted much more strongly... But the Better Geiger S-1 gives an
| accurate _dose_ reading, the Geiger tube or pancake probe will
| dramatically overestimate dose in that scenario, which can cause
| undue concern... In reality it 's pretty harmless levels of
| radiation. :)
| thewanderer1983 wrote:
| >What that commenter misses is that nearly all hobbyist grade
| detectors (Geiger tubes) are not sensitive to alpha
|
| from the original post: "If your Geiger counter is actually
| detecting radiation, it's almost certainly the half-hour lead
| and bismuth. " If you look at the table he provided lead and
| bismuth are beta decay. It is likely he is specifying that on
| the fact that most home geiger counters only detect beta and
| gamma not alpha.
| thadt wrote:
| Hey, that's a pretty slick package (and price point). I looked
| through bettergeiger.com and read the discussion about the
| difference between GM tubes vs scintillators, but never saw an
| indication of what material you're using. Would be useful
| information for those of us thinking of upgrading from an
| SBM-20.
| antognini wrote:
| > hobbyist grade detectors (Geiger tubes) are not sensitive to
| alpha but they are highly sensitive to beta and a little
| sensitivity to gamma.
|
| This was part of the reason why it took so long to discover the
| cause of Alexander Litvinenko's death by Polonium-210
| poisoning. Doctors (and later detectives) had suspected some
| form of radiation poisoning, but the early tests used Geiger
| counters and came back negative. But Po-210 decays almost
| exclusively by emitting an alpha particle which is not
| detectable by Geiger counters. (And it also means it's not very
| dangerous outside the body but becomes extremely toxic if
| ingested.)
| BetterGeiger wrote:
| Yes, and even if you have a high-end alpha detector, ingested
| radioactive material cannot be detected externally if it's
| only emitting alpha. One would need to take a blood sample or
| something like that and do more complicated tests.
| K2h wrote:
| $149 for https://www.bettergeiger.com/product-list/p/better-
| geiger-ra...
| ilyt wrote:
| I'm mildly disappointed that banana is not listed as option
| for test material
| dogben wrote:
| My geiger counter activity goes up when air conditioner is
| working. Never figured out why. This could be a good
| explanation.
| Cerium wrote:
| Is your interior AC unit or its ducting in a basement or
| crawlspace?
| dogben wrote:
| It's interior. No ventilation. I guess it's ionizing the
| air and bringing radioactive dust particles to the whole
| room. The radiation level is still very low so I'm not
| worried.
| detrites wrote:
| Does your AC include a negative ion generator for cleaning
| the air? I wonder if that could be affecting it?
| dogben wrote:
| I don't think it has negative ion generator. I guess the
| fan itself can generate ions, that's why aircraft have
| static dischargers.
| kloch wrote:
| > but they are highly sensitive to beta
|
| I'm not familiar with Geiger counter design/specs but would the
| considerable static electricity send some electrons into the
| detector and cause a false positive beta hit?
| BetterGeiger wrote:
| Beta particles are basically energetic electrons flying
| around, yes, but for a Geiger counter to detect them they
| have to be _quite_ energetic in order to penetrate the Geiger
| tube itself (detection occurs essentially inside the tube, in
| the gas)... So I doubt that static field is generating
| electrons anywhere near that energy needed to be detected by
| a Geiger tube.
| [deleted]
| [deleted]
| Bendy wrote:
| Question fabulously answered by rob whose Stack Exchange avatar
| is also a banger.
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