Cold plasma can inactivate or remove airborne viruses, UMich study shows | Hacker News Reader

Cold plasma can inactivate or remove airborne viruses, UMich study shows

news.umich.edu

75 pointsarto28 comments

Sounds like "air ionizers":

https://en.wikipedia.org/wiki/Air_ioniser#Ions_versus_ozone

see also "Ions versus ozone" (part of the same article):

https://en.wikipedia.org/wiki/Air_ioniser#Ions_versus_ozone

I'm fairly certain any plasma is harder to create than ionized air and the plasma could be maintained only in a relatively small confined space, whereas ions can be freely distributed into a room.

Air ionizers are one option used for cleaning up black mold, fungus, etc. when a building suffers water damage. They're sometimes used to "mop up" after the usual methods of cleaning (washing with anti-fungals, antiseptics, etc.) have been exhausted.

Turn on the ionizer, keep the air circulating, and periodically measure cooties (fungus, bacteria, germs, viruses, etc.) until levels are below tolerance. You leave the premises if using an ozone generator but some models claim to limit ionization to the unit itself, in which case you should be able to live on the premises. Any released ionized particles travel to the remotest parts of the air circulation system for mop-up.

Its old tech that has existed almost since the first spark coil.

“In those void spaces, you’re initiating sparks,” Clack said. “By passing through the packed bed, pathogens in the air stream are oxidized by unstable atoms called radicals. What’s left is a virus that has diminished ability to infect cells.”

That sounds just like ozone sterilisation, something that's been around for a very long time. What's new about this variation?

https://en.wikipedia.org/wiki/Dielectric_barrier_discharge

Probably nothing new. Seems like just supporting PR for all those more expensive "cold plasma" air conditioners at the beginning of the season.

In order for those "soft kill" technologies to work, you need to get all the "big" particles out of the fluid. Similarly to how potable water needs to be filtered and flocculated before chlorination becomes effective. So while this is an alternative to UV or higher-order filtration, it's not replacing filters.

Yeah but what do those radicals do to human tissue? Ozone isn't all that great for your lungs.

If it's great at destroying viruses, it's probably great at damaging human tissue as well.

but if it doesn't stick around for a long time, that's very useful!

Not the point. The idea is that you can quickly sterelize a room buy pumping the stuff then flushing it. It opens the possibility of regular automatic ER cleaning without the need for human intervention and error, plus faster.

Okay, so you sterilize the air and then pump the sterilized air out. Where do you want to get the air to replace that air with?

What good is sterilizing the air if you've got to replace the air after you've sterilized it because it's contaminated with ozone? Is this just a case of not wanting to vent air with more parasites than the atmosphere outside the ER?

Ozone has a half-life of a few hours to a few days, depending on temperature and airflow, so the problem eventually solves itself.

Not if you're using it after every procedure.

- You can use catalysts - you can pump outside air and exhaust the ozone to the outside (creates smog though)

The question is more : does it sterilize surfaces well ? The air is not the most important in the ER.

That's not what they were studying. The title of the study linked in the article is, "Inactivation of airborne viruses using a packed bed non-thermal plasma reactor".

I believe the idea is that the plasma never leaves the filter.

My professor in college was studying this. The big deal was that you could use cold plasma to deactivate bio-films which are resistant to even autoclaving. I guess biofilms are a problem when you are trying to clean hospitals, surgical tools, etc...

The only issue was that she needed helium to ignite the cold plasma in the RF generator. Helium is stupid expensive for this sort of thing.

All hail the .1%

I remember watching a talk from a chap who started his own cleaning business. They found themselves doing more and more "niche" cleaning - mopping up blood spillages in nightclubs, working with police cleaning houses after gruesome murders or just old guys who fell down the stairs and weren't found for months. Apparently, getting brain matter out of stair carpets is a real challenge.

Anyway, they were using off-the-shelf cleaners for this kind of thing, with 99.9% promises on the bottles. At some point, they had to submit samples of their cleaning agents for testing.

Turns out, some of the 0.1% of viruses and bacteria happened to include the really bad ones - Hepatitis I believe was one of the scariest survivors (particularly problematic in nightclub blood cleanups) and some of them even thrived in the chemicals.

That said, I don't think that's what this article is saying, as they aren't testing different pathogens - they're testing a single pathogen, and only 0.1% of the mass passed through remained viable. Still, don't underestimate that 0.1%. If it can multiply, it can kill you.

Yeah, make them immune to that too. Improves the chances of life spreading across universe.

Plasma isn't like antibiotics. There's no enzyme that can degrade it, and no transporter that can pump it out of the cell. Its damage is untargeted, so the only way to resist it is to become generally tougher, which has high metabolic cost. The microbes that don't evolve this will out-compete them. Worrying about resistance to plasma (or similarly indiscriminate antimicrobials, like bleach or ionizing radiation) is like worrying about animals evolving armor plating to resist bullets.

Seems like a really good way of creating a niche for plasma proof viruses.

Could this lead to mutated super-viruses?

Likely not. Mutation that will help to survive this type of sterilization likely will not help virus to be more effective in other aspects. For example extremophiles are not very effective as infections.

Not within our lifetimes (and several thousands of years on top of that), probably

We have antibiotic resistant bacteria already today, and antibiotics were invented less than 100 years ago.

That's a very different thing. Adapting to antibiotics is not comparable to adapting to something wildly different and new

Could virus mutate to be resistant to that? Sure, why not. Will it be super-virus? Depends on what is super-virus. If it means more deadly, then probably not, since this resistance is most likely not related to deadliness.

In fact the mutation is likely to make it slightly less deadly, since it's likely to involve tradeoffs that make the virus less fit for other purposes.

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