What's good in small concentrations, but lethal in higher? What's a glaring red flag you're encroaching on a lethal concentration?

ilex@lemmy.world to No Stupid Questions@lemmy.world – 102 points –

Like Fluoride or Oxygen.

126

Just about anything including water or salt

Not just about. Literally everything is lethal at a high enough concentration.

Alle Dinge sind Gift, und nichts ist ohne Gift; allein die Dosis macht, dass ein Ding kein Gift ist.

All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.

Paracelsus, 1538

The word for poison in German is Gift?!

The word has been used as a euphemism for "poison" since Old High German, a semantic loan from Late Latin dosis (“dose”), from Ancient Greek δόσις (dósis, “gift; dose of medicine”). The original meaning "gift" has disappeared in contemporary Standard German, but remains in some compounds (see Mitgift). Compare also Dutch gift (“gift”) alongside gif (“poison”).

Well that's dumb.

"gift" means both "poison" and "married" in swedish. languages are fun :)

Some people would not see a difference in those words, so why not use the same and decide on context xD

The first part of the question asks what is safe in small amounts

I'd argue gravitational force isn't lethal. As long as you don't arrive at whatever is pulling you & the gradient of gravity doesn't change across your body length. You could be perfectly fine (for a while) orbiting a black hole at enormous speeds (assuming you don't collide with matter in the accretion disc.

I'd argue against that. For one thing it is impossible to imagine a situation where there is no change in the gravitational gradient across your body over time. Your orbiting a black hole situation is a perfect example of a situation where the gradient alone would tear you apart. The conditions you've specified are tautological. There's no way to maintain a zero gravitational gradient while also simultaneously having extremely high gravitational field. The two are mutually exclusive in any conceivable scenario.

It's like saying a human being in a hypersonic wind stream won't necessarily hurt you, burn you alive and rip you to pieces (not necessarily in that order) as long as there is no turbulence and you have a sufficient boundary layer -- but you're a non-aerodynamic human body in a hypersonic wind stream, so of course there will be turbulence and the boundary layer will not protect you at all, you're going to die, basically instantly.

Does the change in gravity gradient across your body kill you right now? No? You are currently orbiting the supermassive black hole in the center of the milky way. You and everything else in the milky way aside from a few intergalactic objects just traveling through.

I am not an astrophysicist, but I do understand basic physics.

Does the change in gravity gradient across your body kill you right now? No? You are currently orbiting the supermassive black hole in the center of the milky way.

It was implied by "accretion disc" and by the fact that we're talking about gravitational gradients at all that we're talking about a close orbit. Gravitational strength gets smaller with distance according to the inverse square law, so by the time you're a few light years out from the galactic core the gravitational gradient is already extremely insignificant.

Accretion discs can be large enough that I am pretty sure a human body wouldn't be torn apart at that distance (at least the outer bits) by the difference in gravity across it's length. In the linked article about the supermassive black hole at the center of the Milky Way, we're talking 1000 astronomic units, so 1.5 * 10^14 meters.

The current value of this black hole's mass is estimated at ca. 4.154±0.014 million solar masses.

So let's calculate the equivalent distance from the sun in terms of gravitational force on an object at the outer edge of the accretion disk:

F_sun = C * (R_equivalent)^-2 * m_object

F_black_hole = C * 4.15*10^6 * (R_accretion_disk)^-2 * m_object

where C equals the gravity constant times the mass of our sun.

==> C * (R_equivalent)^-2 * m_object = C * 4.15*10^6 * (R_accretion_disk)^-2 * m_object

divide by C and m_object:

<=> (R_equivalent)^-2 = 4.15*10^6 * (R_accretion_disk)^-2

invert:

<=> R_equivalent^2 = (1/4.15) * 10^-6 * (R_accretion_disk)^2

==> R_equivalent^2 ~= 0.241 * 10^-6 * (R_accretion_disk)^2

square root (only the positive solution makes sense here):

==> R_equivalent ~= 0.491 * 10^-3 * R_accretion_disk

with R_accretion_disk = 1000 astronomic units = 10^3 AU

<=> R_equivalent ~= 0.491 * 10^-3 * 10^3 AU

<=> R_equivalent ~= 0.491 AU

Unless I have a mistake in my math, I sincerely hope you will agree that the gravitational field (tidal forces) of the sun is very much survivable at a distance of 0.491 astronomical units - especially since the planet Mercury approaches the sun to about 0.307 AUs in its perihelion.

If the gravity were strong enough and the source close enough then the tidal force would absolutely be strong enough to simultaneously crush you and rip you apart. The same effect gives rise to tides on this planet, hence the name.

Your orbiting a black hole situation is a perfect example of a situation where the gradient alone would tear you apart.

I just proved this claim of yours wrong, and then you move the goalposts. I said from the very beginning that a gravity gradient is a problem.

I studied Relativity at university as part of combined Physics/Maths degree, but please feel free to continue entertaining us with your popular magazine-based learnings.

You argue that it isn't, and then provide several examples where it is.

Can't help you if you don't understand what "ideal cases" are, when the real world examples are not practical to describe the underlying principle. The point is: gravity doesn't kill you, no matter how high the absolute. Arguably, in a perfect gravitational field, you could even be accelerated at insane speeds without experiencing discomfort, because each atom of your body would be experiencing the same acceleration.

I think General Relativity is based on the idea that a frame of reference that's in freefall is equivalent to one that in a gravity free region of space (at least that was one of Einstein's Gedankenexperiments that led him to his theory of GR).

Having said that, in reality a sufficiently strong gravitational field will cause a tidal effect, which will crush you along one axis and pull you apart along another.

There was definitely something like that - I am not sure if free-fall and being accelerated in a gravitational field are the same though. It may be that GR is talking about moving along lines in space-time that have the same gravitational potential (orbits), and moving across potential lines counts as an accelerated frame of reference in which you wouldn't observe the same as in a reference frame moving at constant speed.

I was thinking of the Equivalence Principle:

the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference.

okay, but that would be an accelerated frame of reference, not equivalent to one that is "gravity free"

Wouldn't a high enough force cause the gradient of gravity to differ?

Unless I misunderstood how that works. I'm picturing a downed powerline that causes large differences in voltage across the ground, which is why you are supposed to shuffle instead of taking a normal step. Would a high enough gravity cause a harmful gradient across the length of a human body?

The term spaghettification comes into mind.

Like if you were free falling into a black hole, the gravity forces would rip you to shreds long before you ever actually impacted anything because the difference in the force of gravity on the parts of your body that are closer to the black hole and the parts of your body that are farther away are enough to shred you like lettuce.

I have read popular scientific articles however according to which in a large enough black hole, it may be possible to fall through the event horizon before being inconvenienced by the gravity gradient, and even the smartest physicists do not know for sure what will happen beyond the event horizon. In theory, there could be the beginning of another universe there :) Like - the singularity at the center of the black hole could expand as a big bang into a brand new universe "on the other side".

Gradient: the change of a value (here: gravitational force, or rather: potential) over a reference variable (here e.g. the length of the body)

No, the absolute value of the gravitational force does not matter for the gradient. Gravitational force (potential) is proportional to the inverse distance squared from the center of mass that exerts the gravitational potential. If your distance from the object R is large enough, then the gradient of gravity across the length of your body is negligible: In the worst case, with your body length being s, the gravity at the part of your body closest to the center of mass pulling you would be: F_max = F_min * ( R^2 / (R-s)^2 ), and with s << R, this becomes F_min, the force at the part of your body furthest away from the mass pulling you in.

This becomes problematic when you get "too close" to the body in question - and where too close begins, depends indeed on the absolute force. But for each black hole, there's a safe distance at which you could fall around it, assuming no other factors killing you (like intersteller particles, or an accretion disc)

Makes sense, thank you :)

I thought about this a bit and concluded that it only applies to physical materials and forces.

For example: There certainly are lethal ideas, but most of them are not, and much like bosons they can overlap, so filling a person with multiple copies of the same (benign) thought has a diminishing effect.

But yeah, anything physical has a lethal concentration.

Panadol / Paracetamol / Tylenol / Acetaminophen / C8H9NO2 is exceptionally easy to overdose on. I've done it accidentally a couple of times. It causes liver damage at even lower overdoses, you really don't want that.

The maximum dosage is 1g every 4 to 6 hours, maximum total 4g a day. I am no doctor but I strongly recommend 6+ hours between doses (I set a timer) and I try very hard to not get to 3g or above per day. It's even worse that plenty of medications just throw it in to the mix casually.

Unfortunately as the only first line of defence I have against pain, I cannot avoid it altogether. Redflags for me were light abdominal pain and yellowing of skin under eyes. Plus fatigue, but that's normal in my world.

Huh. That might explain the last two weeks. Dental pains. Lot's of tylenol. And why I feel much better now.

For dental pain I recommend ibuprofen (advil). Seems to work significantly better than acetaminophen (Tylenol) and seems to be much safer.

NSAIDs can be just as bad in different ways. They cause your digestive tract to bleed and can cause perforations.

Tylenol can be taken with ibuprofen to increase pain or fever relief. Just follow directions for both.

Definitely ease up on it if you can, especially if you've been taking it for more than a week regularly. If you can't reduce usage/dose, then be much more generous with the minimum gap between doses, especially if your liver is already under a bit of pressure from other meds or alcohol.

Pain sucks, and pain management causes pain. Sorry about the dental stuff, my issue isn't teeth but I know that is no fun too.

I accidentally overdosed on acetaminophen after a surgery once. Doctor forgot to tell me (or I was still high when he told me) he gave me acetaminophen during/after the surgery. I thought I still could take up to 4g that day. A few hours after the surgery, the pain started to kick in so I took some acetaminophen. Ended up vomiting uncontrollably.

Can you not use ibuprofen?

Sadly no, the entire NSAID class are off the table. I'm one of the "lucky" few who gets one of the rare but serious side effects.

Weed. A gram will get you high. A woolpack full of it can crush you like a grape if falling from the hay loft.

woolpack
From Middle English wolpak, wullepak, equivalent to wool +‎ pack. 
A bag of wool, traditionally weighing 240 pounds.

TIL, Thx

Took a Hazmat class today and the big thing they drilled into our heads was "Everything is toxic at scale." So make anything you want and there is an IDLH concentration.

Age

I think this is one of those "any amount is bad" things.

Optimal age to be is blastocyst. It's just downhill from there.

To quote, poorly from memory, the wisdom of Silenus "The best fate for a man is to never have been born at all, the second best fate is to die quickly."

dying is a pretty big red flag, you ask me.

Okay. Do you think dying is a pretty big red flag?

I guess I did ask for that.

I also guess you like to tell dad jokes.

Everything is good in moderation. Even drinking too much water can lead to death.

It’s been said a lot that light alcohol consumption is actually good for your health, but this is not actually true. It improves some health outcomes but the benefits are outweighed by the risk. There is no safe amount of alcohol consumption.

Hilarious how the alcohol lobby scratched around for years looking for a good news story about alcohol and came back with some weak sauce link between red wine and heart disease. Meanwhile, 50% of reported sexual assaults are linked with alcohol. Probably more like 80%. How is alcohol legal and LSD is a schedule 1 substance? There is no lethal dose and has been discovered as a treatment for resistant depression and PTSD, OCD, etc. Our drug laws are completely wack.

The real elephant in the room is alcohol is much more destructive and just as addictive than measurable controlled doses of opoids, and also equally if not more destructive than stimulants like amphetamines and cocaine. It's basically the worst drug in every metric. If every alcoholic got their drinks replaced with MS Contin and or weed, the strain on the health system would be much less. Not to mention all the other negative externalities related to alcohol intoxication.

I say all this as someone who drinks. I am going to ensure my child is aware of all the negatives at an early age and be open to discussion about substances. People either like or dislike alcohol, and the people who like it have no self control. It's a stupid drug, I wish I was never introduced the way I was.

Don't even get me started on the alcohol companies producing alcoholic mountain Dew, freeze pops and Sunny D... and they have the gall to ban flavored vapes haha.

I have a feeling that alcohol will come to be viewed in a similar way we now look at religion. It's a cultural artefact from an ignorant time. It serves some purpose and there is a basic utility but overall it has a toxic effect. I hear that research is ongoing to find a credible alternative molecule without the deleterious health outcomes.

Western society has a generally incoherent and childish attitude to substances. Some are viewed as evil e.g. heroin but when this drug turns up in a therapeutic setting, it inexplicably becomes medicinal i.e. diacetylmorphine, which is the acceptable face of heroin, used for terminal cancer treatment.

No substance should be viewed as either panacea or disaster. They are tools that we can use when the time and place is appropriate. We ought to educate ourselves and have honest conversations. Prohibition is getting in the way of this effort and it must go. In it's place we install education, healthcare and hygiene for the mind.

Happy to find a fellow psychonaut. What's your next project in this area? I am considering a psychedelic voyage to the Netherlands.

Haha, I am a bit on the older side and basically have took all my trips. I have a hallucinagen stash for every couple years with my wife, but that's about it. I have tried almost everything at this point.

I would like to take one of those camel desert treks, where before bed you get to smoke opium and then cuddle with a camel for warmth while you sleep. That sounds like the best nights sleep possible... Although it's relatively weak opiate, opium is supposedly a very unique high compared to other opiates. My uncle did it decades ago and he said it was one of the best times of his life. Unfortunately there are few countries that offer the experience, and a few of them are going through very dangerous internal strife. (I mean the countries don't support the drug use, they just turn a blind eye)

I've had a few trips over the years but never used them in a therapeutic setting. My mental health has become more fragile as I've got older and I took up meditation over the last year in an effort to improve it. They say that meditation works by stilling something called the Default Mode Network and psychedelic drugs also work on this process in your mind but in a completely different way. The plan is to take a Heroic Dose of mushrooms (people say 5g of dry shrooms) and then do an assimilation session afterwards. The session is guided by an experienced person.

Your camel adventure sounds great but all the camels I met so far have been hella grumpy. I would be worried that they were going to bite me for snoring too much. Well, that's what my wife does.

ionizing radiation, according to some hypothesis, vitamin E, selenium, zinc,

there's no single "red flag" everything is different

Everything. Literally everything can be fatal in large enough quantities. Quote from one of my chemistry professors: "there are no lethal substances, only lethal doses"

"The dose makes the poison" -some old dude that like found the pharmaceutical industry

3 more...

There are lots of things that our body needs in really small doses. But anything above can be lethal.

Some things needs to be in really specific compounds. Like chrome we need really small dose of Cr3+ but Cr6+ is carcinogenic.

Acetaminophen/Paracetamol. The safe therapeutic dose is very close to the toxic dose. While most people don't intentionally overdose, at least not for treating illness symptoms, the problem arises when they take multiple medications that all contain acetaminophen, following the label for all of them can easily net you a toxic dose.

Chubbyemu video: https://www.youtube.com/watch?v=VSqrCgFMsCI

Some good fan service in that video

My medication. Lithium in small exactly precise doses according to each individual is helpful. But we have to take blood tests to check the toxicity.

We have to stay hydrated and be really careful if we are sick or vomiting

A warning signs is shaking (I tests my hands regularly), nausea and outcome is dying. Ha.

The human body is pretty weak so anything in high concentrations can probably kill us. It's no steel

Heartbeats. 60 - 70 is good (you can get away with lower if you're fit, but anything below 40 is bad), and anything above 180 - 200+ tends to be quite bad for your health.

Is there a lethal heartbeat? Google didn't immediately tell me.

Yes. Anything above 220 tend to be quite bad for your health, since there's not enough time for your heart's chambers to fill at that speed.

As usual with biology, there's exceptions to the rule, but for your average human, anything past that means that there's usually not enough blood coming out to keep you alive at those speeds, and your heart may as well not be beating at all, for all the good it does.

It's similar to why Ventricular Fibrillation is bad for you, since it's a similar problem (but only limited to the two main pumping chambers/ventricles of the heart, rather than including the atria).

Vitamin A. Probably others as well.

Also, water.

Blood sugar. Vital that you have enough to continue functioning but if it stays too high for too long, it will disable and eventually kill you.

Nicotine, small doses can be okay, but large doses and it's really lethal

Many plant-based drugs, including nicotine, originated as natural insecticides: the plant uses them to make itself poisonous to insects that would eat it.

But impossible to overdose by voluntary inhalation. Just don't eat, drink or inject lethal doses and you'll be fine.

I'm not sure bout that. I know they say it, but on many occasions I've taken 80+mg orally in a day. Lethal dose is supposed to be 60.

Ld50 is usually in units per kg, so unless you are a pixie, 90 is well under that number.

Remember that the ld50 is lethal for 50% of people (healthy adults? Something like that.)

Ld50 is not something I knew about when I asked. I'll pay more attention next time I see some info on it. I'm not abusing nicotine cessation products as much so my interest in researching it has waned.

I'm learning more than I thought I would from this question.

Booze... Nurofen

Apparently there is no longer a lower limit where alcohol is considered beneficial, at all.

https://www.who.int/europe/news/item/04-01-2023-no-level-of-alcohol-consumption-is-safe-for-our-health

I was thinking more the "merry" side of good rather than healthy good

Ah, I see. It was a surprise to me to hear, after years of being told that a glass of red wine per day is good for us. So I generally assume it’s a surprise to others.

LSD

There is no lethal dose of LSD

I'm sure drowning or inhaling it would be fatal. Or something similar to drinking too much water.

brb replacing all my bodily fluids with LSD, will let you know how it goes

Yeah but then that could be said about literally everything.

Which is why everything has a fatal dose

But it's a nothing comment. Water has an LD50. It's 90ml/kg. LSD has no known LD50 and has not been the sole cause of any known death. Drowning in it would not mean you died from LSD toxicity, you would die from asphyxiation. Sand doesn't have a lethal dose but can still kill you. But it wouldn't be from sand overdose.

I had a friend that od'd on LSD. His brain swelled up and actually cracked his skull. He was only 20. His sister rushed him to the hospital, but he was brain dead by then.

I had a friend that od’d on LDS. He started going on about magic gold plates and last I heard he moved to Utah and had 11 kids.

This user is lying.

Why would I lie about a friend dying? I was just sharing my experience. Believe it or not, it doesn't make any difference to me.

I have no doubt your friend died. What you're lying about is that his death was by an LSD overdose. Thats impossible. Hence why you're lying.

Was that before or after your other friend took a hit on a joint that was laced with PCP and they ripped their own face off their skull while looking in the mirror?

It's impossible to say for certain what caused that death without more info, but I can very confidently say that it was not LSD.

That's what the death cert said, but those aren't infallible.