I didn’t realize at first that this was cross-posted from EAF, so since this seems to be getting more attention here I’ll repost my comment from there here:
You don’t mention this, and maybe there is no research on it, but do we expect there to be much opportunity for resistance effects, similar to what we see with antibiotics and the evolution of resistant strains?
For example, would the deployment of large amounts of far-ultraviolet lamps result in selection pressures on microbes to become resistant to them? I think it’s not clear, since for example we don’t seem to see lots of heat resistant microbes evolving (outside of places like thermal vents) even though we regularly use high heat to kill them.
And even if it did would it be worth the tradeoff? For example, I think even if we knew about the possibility of antibiotic resistance bacteria when penicillin was created, we would still have used penicillin extensively because it was able to cure so many diseases and increase human welfare, although we might have done it with greater care about protocols and their enforcement, so with hindsight maybe we would do something similar here with far-ultraviolet light if we used it.
Some bacterial species have impressive level of radiation resistance, so it’s a quality that can certainly be evolved much like antibiotic resistance. The most extreme radiation-resistance strategies involve the presence of multiple genomes within a cell as “backups”, this is coupled with various metabolic activities which have the goal to replace/repair the “main one” when it is damaged by radiation. Viruses, on the other hand, completely lack a metabolism and therefore will have serious trouble developing this kind of resistance.
I agree with this, plus note that UVC is actually more dangerous than radiation for bacteria, because the number of photons per watt is significantly greater and the energy per photon is already enough to do damage.
I am not an expert on viral and bacterial resistance to UV radiation. Some googling reveals that bacteria can evolve partial resistance to some forms of UV. In th following paper, the bacteria survived roughly a minute of UVB exposure from a 15W source: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1558-5646.2011.01438.x
But I don’t think they can evolve to be totally resistant, i.e. just sit under a UV light at 250nm or 220nm indefinitely. UV is fundamentally harmful to bacteria because their germ line cannot be protected from it, kind of like how humans are fundamentally vulnerable to gamma rays.
The same goes for viruses, except they also cannot repair themselves and they’re even smaller which makes them more vulnerable.
I think that for viruses it will be difficult to become completely radiation resistant, as it would require complete overhaul of their makeup: thicker walls, stronger self-repair.
I didn’t realize at first that this was cross-posted from EAF, so since this seems to be getting more attention here I’ll repost my comment from there here:
You don’t mention this, and maybe there is no research on it, but do we expect there to be much opportunity for resistance effects, similar to what we see with antibiotics and the evolution of resistant strains?
For example, would the deployment of large amounts of far-ultraviolet lamps result in selection pressures on microbes to become resistant to them? I think it’s not clear, since for example we don’t seem to see lots of heat resistant microbes evolving (outside of places like thermal vents) even though we regularly use high heat to kill them.
And even if it did would it be worth the tradeoff? For example, I think even if we knew about the possibility of antibiotic resistance bacteria when penicillin was created, we would still have used penicillin extensively because it was able to cure so many diseases and increase human welfare, although we might have done it with greater care about protocols and their enforcement, so with hindsight maybe we would do something similar here with far-ultraviolet light if we used it.
Some bacterial species have impressive level of radiation resistance, so it’s a quality that can certainly be evolved much like antibiotic resistance. The most extreme radiation-resistance strategies involve the presence of multiple genomes within a cell as “backups”, this is coupled with various metabolic activities which have the goal to replace/repair the “main one” when it is damaged by radiation. Viruses, on the other hand, completely lack a metabolism and therefore will have serious trouble developing this kind of resistance.
I agree with this, plus note that UVC is actually more dangerous than radiation for bacteria, because the number of photons per watt is significantly greater and the energy per photon is already enough to do damage.
Is number of photons greater or energy of each photon?
the number of photons per second per watt of power is a lot greater for UVC than for gamma radiation.
If the number of photons per Joule* is higher for UVC, that means that each photon carries less energy.
*A Watt is a Joule per second; sustaining a Watt of power for one second requires a Joule of energy.
I am not an expert on viral and bacterial resistance to UV radiation. Some googling reveals that bacteria can evolve partial resistance to some forms of UV. In th following paper, the bacteria survived roughly a minute of UVB exposure from a 15W source: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1558-5646.2011.01438.x
But I don’t think they can evolve to be totally resistant, i.e. just sit under a UV light at 250nm or 220nm indefinitely. UV is fundamentally harmful to bacteria because their germ line cannot be protected from it, kind of like how humans are fundamentally vulnerable to gamma rays.
The same goes for viruses, except they also cannot repair themselves and they’re even smaller which makes them more vulnerable.
I think that for viruses it will be difficult to become completely radiation resistant, as it would require complete overhaul of their makeup: thicker walls, stronger self-repair.