Great to see the preprint! Kevin Esvelt also explains the approach in his EAG Boston 2023 talk (starting around 20min): 

No wonder Bulby is unhappy; they're missing a good chunk of their head! 

Thanks for digging into the repo 

Does somebody have the image file of the sensitive, sentient lightbulb that visited the forum dropdown menu two days ago? 

That's really sad to hear! Given the number of events hosted there and the renting costs of alternative venues, it seemed like a solid investment (while also being much more picturesque, of course). So, I'm also hoping for a post-mortem with more details. 

I'm personally not that worried about substitution risks. Roughly: The deterrence aspect is strongest for low-resource threat actors and—from a tail-risk perspective—bio is probably the most dangerous thing they can utilize, with that pesky self-replication and whatnot. 

Hi Sean,

Thanks for the write-up and opening the discussion. I agree that material degradation is something that should be thoroughly investigated. Caveat: I'm not a polymer engineer and have read/seen a few papers/talks on the topic, but I'm by no means deeply familiar with all the material types, etc.

Re. the Boeing study (working link, btw): The study used fairly low doses per disinfection cycle but simulated 25 years of service, totalling >108 J/cm² of far-UV exposure. Still just about a third of the bus study exposure, but already in the dose range where the bus study measured only marginal effects of additional far-UV on colour or mechanical properties. 

Still, I don't find myself overly worried (but again, not an expert and I also don't have regulator-brain, so interpret this accordingly).

Far-UV doesn't penetrate deeply and will likely not affect the mechanical properties of solid plastic objects. The bus study found effects in thin sheets of fibre-reinforced materials (in some directions), and I don't doubt that, but in what situations is a 10% decrease in failure strength of thin polymer layers that relevant for consumers or regulators? I genuinely don't know, and there might be specific circumstances in which parts must be replaced more frequently, or the plastic type needs to be switched, but I don't think this will matter a lot in most settings. E.g., Boeing found "no adverse impact on the mechanical properties of thermoplastic and textile materials" in the airplane setting at the dose where the bus study already saw decreased tensile strength. I'm very interested in hearing counterexamples, though! 

But ultimately, both Boeing and the bus study have only tested the materials present in those surroundings. Looking around in my office or the office of friends, I'm not sure how many of the materials overlap. There's some testing behind closed doors from lamp manufacturers, but no public database of common materials and the impact of far-UV on them. We eventually want and need such a database to make the far-UV implementation as pain- and seamless as possible for building operators, etc., but I'm not sure how much the average office worker or regulator cares if the back cover of their monitors starts yellowing faster (like you said, open question: Market research opportunity!). 

And in the beachhead markets for far-UV (long-term care homes, ICUs), the cost–benefit calculus is favouring far-UV so much that a premium for far-UV coatings will happily be paid if yellowing is even something they care about. And the plethora of single-use plastics are not affected. 

That's likely an even smaller issue. Far-UV inactivates the transient microbiome on the upper skin surface but not in the pores where the majority of the bacteria live. It’s also strictly line of sight and the skin is pretty wrinkly and only small areas (e.g., back of the hands) are exposed and you constantly re-seed your microbiome from other parts of the body. There’s prelim data from hairless mice which found no changes to the microbiome.

Everything touched by the immune system is complicated, agree. But I strongly suspect the net balance will be highly positive, still:

a) As you wrote, seasonal respiratory disease is a massive problem, in the order of trillions of dollars of health and economic damage every year

b) There is some cross-reactivity, yes, but the tail events will be too different from what we usually have. Frequent common-cold exposure will not be the thing that protects us from a GCBR. Neither will the original antigenic sin play a role, as that usually requires quite closely related strains to matter. Overall, your immune system will be a bit less-well prepared for this particular pathogen family that you haven't encountered in a while, but that's also the case for any other sufficiently different pathogen. 

Re. cost reductions: That's a bit tricky. With the current lamp tech (KrCl excimer lamps), 20x is not on the table. Their cost floor is closer to 1/3 of the current cost. Next-gen (read: solid-state) emitters can achieve 20x in principle but are often still bottlenecked by fundamental academic research; we're eventually talking about ~5–10 years and 10s to 100s of M of $ to get to fab scale. There are two startups around a different promising approach that might be a bit faster but will require the same money. 

For any technologies that have a market, $100M of investment are doable, but far-UV faces a bit of a circular problem: Missing data (safety/effectiveness) → No official recommendations → No market → No emitter R&D and high product prices → Insufficient deployment that limits real-world data. There are now some market-shaping initiatives that will hopefully ameliorate this dynamic so that R&D money flows naturally. But as Max wrote, OP will hopefully also address some of those points after their RFI. 

Re. IAQ: The ozone/VOC data are still somewhat contested and in flux, so it remains to be seen what the far-UV impact on real-world IAQ will actually be. But you're generally right; it's best to view the IAQ interventions holistically. Ventilation/filtration can complement far-UV, and the best deployment scheme will depend on the environment. But I still don't worry too much about cost/flexibility limitations, as most environments in which far-UV would be first installed already have decent air handling systems (hospitals, airports, etc.)