[mr_toad]

I don’t understand why the innate immune response wouldn’t default to attacking an organism made of chiral molecules, since it attacks anything it doesn’t recognise.

And while the adaptive immune response might not immediately recognise a novel organism, is there something that would prevent it ever adapting?

[Filligree]

I’m sure it would attack it, and it likely would even succeed.

The problem is the chiral molecules would be difficult to clean up. You’d have this anti-life bacteria torn to pieces, yes, but then the pieces get stuck everywhere and potentially jam things.

Personally—not a biologist—it doesn’t feel like a huge risk, given we accept threats such as microplastics which do much the same thing. However, it’s a completely unnecessary threat with essentially no upsides, and it wouldn’t be possible to undo once created.

[tw04]

Do we really "accept" microplastics? It seems to me most scientists in the field are terrified of microplastics, while simultaneously acknowledging it's a problem that we almost assuredly can't realistically solve on any reasonable timescale.

I'm confident if we had seen microplastics coming when we first started using plastics, science at least would have tried to prevent their use becoming as widespread as it has.

[sitkack]

Humanity knew very well that lead and mercury were highly toxic and yet only recently are they being phased out in widespread use.

The Man Who Accidentally Killed The Most People In History https://www.youtube.com/watch?v=9sm1qxqdRyY

Hundreds of millions of pounds of Glyphosate is spread across the entire globe.

Scientists don't have much say in these things.

[cyberax]

> Hundreds of millions of pounds of Glyphosate is spread across the entire globe.

And none of it is harmful to humans.

[Supermancho]

> > Hundreds of millions of pounds of Glyphosate is spread across the entire globe.

> And none of it is harmful to humans.

As Monsanto assures us, except when https://www.youtube.com/watch?v=ovKw6YjqSfM (extremists are funny)

To be fair, safety is a matter of concentration and exposure. It's not safe, per se, as with any pesticide. The question is about it's lingering effects.

https://usrtk.org/pesticides/glyphosate-health-concerns/

[gus_massa]

Table salt is safe, but you definetively not want to eat a full glass of table salt. I guess it's fatal.

Sugar is perhaps safe, there is a test for diabetes during pregnancy that consist in drinking a (small) glass of very concentrated sugar solution. I think it's not a full glass, so don't try it without medical doctor authorization and supervision.

A glass of food oil? Does it give you diarrhea?

A glass of alcohol? It's like two glasses of vodka. I think you get alcoholic coma or worse.

Also, the level of purification is different for food/medicine and other applications. Don't try to eat the salt that is sold to clean snow.

[cyberax]

Yeah, yeah. Proof by a video from an eco-terrorist group is the best thing ever.

I would have just punched that smug moron in the face. So kudos for the Monsanto guy.

> To be fair, safety is a matter of concentration and exposure. It's not safe, per se, as with any pesticide.

It actually IS safe at any sane level. The surfactant that is added to the formulations is more dangerous than glyphosate itself.

Sometimes things are just black and white.

[cj]

Humans only respond to acute threats. As a society we don’t have a means of effectively responding to long-term threats. We seem to only care about the next 5-10 years. Our species is short sighted, but I suppose evolution will correct that, eventually.

[deadbabe]

Well the average remaining life expectancy of all adult humans currently alive is probably only a little more than 10 years so it makes sense.

[throwaway0123_5]

Are you suggesting a massive collapse is likely in ~10 years?

[fc417fc802]

> It seems to me most scientists in the field are terrified of microplastics

Got anything you can point to? I haven't looked for a while but last time I did the evidence of harm appeared quite minimal. I recall that it was quite toxic in aquatic environments that had already been contaminated with (previously mostly harmless) low levels of heavy metals.

PTFE is similar in that it too hangs around in the environment for ages which is certainly a cause for concern. Yet it seems to be difficult to track down any known concrete negative effects. (If you are aware of any I would be interested in learning about them.)

[tw04]

Sure, here’s one that’s particularly disturbing and I can’t imagine long term is classified as benign.

https://www.npr.org/sections/health-shots/2024/05/22/1252831...

[fc417fc802]

I think this still fits the pattern I was referring to. Observation of a concerning trend but minimal or no direct evidence of harm. In this case accumulation in reproductive organs.

That article cites (https://pmc.ncbi.nlm.nih.gov/articles/PMC9134445).

> Animal studies have shown exposure to microplastics can impact sperm quality and male fertility,

That paper covers numerous aspects. Regarding specifically reproductive harm in mammals, it in turn cites numerous other studies at which point it becomes rather time consuming for me to get up to speed in the nuances of a field that I'm not intimately familiar with.

Having checked at least a few of the relevant citations, it looks like (most of?) the research in animal models involves short term acute rather than long term low level exposure. Not being an expert in this specific area I can't readily assess the quality or applicability of such studies. At least from what I looked through just now I'm not at all convinced that what the current animal studies are showing is (necessarily) directly relevant to low level environmental exposure.

https://pubmed.ncbi.nlm.nih.gov/30176444/

> exposed to 5 μm polystyrene MP at the concentrations of 100 (approximately 1.456 × 106 particles/L) and 1000 μg/L (approximately 1.456 × 107 particles/L) for the toxicological experiment.

https://pubmed.ncbi.nlm.nih.gov/32659591/

> the 0.5 μm, 4 μm, 10 μm polystyrene microplastics (PS-MPs) treatment groups were given 100 μL PS-MPs (10 mg/mL) by oral gavage once a day.

From my perspective there are a couple huge red flags here, and they seem to be present in all the studies I checked just now. I didn't immediately see comparisons of these protocols to the environmental conditions in the world at large (either current or predicted). Neither did I immediately see quantification of the degree and nature of the observed tissue accumulation in comparison to that observed in tissue samples collected in the wild. The latter is of particular concern because these accumulations in the laboratory happened very rapidly (over the course of a few weeks) in the face of acute exposure and impacts were then immediately measured. That doesn't really resemble what's going on in the world at large.

It is of course entirely possible that I missed something when quickly looking over studies that are outside my area of expertise. Apologies if so.

Lest it seem to you that I'm being overly pedantic here consider the difference in outcome for chlorine exposure between long term low level (ie tap water) and short term acute (ie poisoning).

[kragen]

Well, not anything. I have glass embedded in my foot which isn't being attacked, for example, and there are plenty of examples of biocompatible polymers, many of them already used in medical implants.

(By the way, all organisms are made of chiral molecules; what we're talking about is reversing the chirality.)

Some of the things the immune system uses to attack things, such as superoxide, would work fine on mirror organisms. Others, such as antibodies to existing organisms, wouldn't work at all. I don't know what the balance is.

[michaelmrose]

Stuff binds to other stuff because the magnetic domains and shape match up well enough.

There is no way to effect something that attacks everything it doesn't recognize because a) there is no ooeration that represents not matching and b) if there was such a cell would be a short lived bomb that would blow up your body.

You adaptive immune system learns to and antigen when a short lived immune cell is semi randomly generated that binds to it and becomes a longer lived cell.

Presumably this could still happen but this normally takes days to happen. In between your inate immune system relies on being able to recognize a lot of existing antigens that are out there and common in attackers.

Having the entire library of malicious life become magically unknown means that you are relying on only your adaptive immune system is available to contain the damage.

[dekhn]

Magnetism does not play a role in binding in biology. The primary determinants of binding are: shape complementarity, electrostatic interactions, van der waals forces, and some amount of hard to explain entropy.

(biomagnetism is a thing, but I'm not aware of any cases where binding occurs due to magnetic forces)

[aeonik]

I think they might have meant they are all geometrically defined EM interactions.

[f1shy]

In biology is much much muuuuch more about physics as chemistry. Is all about the shapes of very big molecules.

[selimthegrim]

There are already examples of immunosilent (to humans) lipids like in Moritella.