Comment by devy | Hacker News Reader

Comment by devy | Hacker News Reader

The simple answer is it probably can, but the actual facts are more nuanced than a simple confirmation.

All bio-safety labs or hospitals or water treatment plants or special HVAC systems have UV-C lamps to sanitize pathogens because UV-C radiation destroying nucleic acids (DNAs / RNAs).[1] However, the effectiveness really depends on the amount exposure/energy level, light of sight(because UV-C doesn't penetrate deep into objects), and even dust in the air or the on the UV-C light lamps(which reduced the energy they emit) as well as how DNA/RNA can be evolved or self-repaired.

Anecdotally, Chinese hospitals are using UV-C lamp to sanitize their medical equipments, masks (when it was in short supply months ago) among other things.

And yes, more exhaustive experiments should be conducted to affirm this practice as it's the most non-toxic and energy efficient way to sanitize surfaces.

[1]: https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia...

[2]: https://www.cnbc.com/2020/03/18/how-china-is-using-robots-an...

There's 2 things to also note:

1: Don't try this at home! If you are directly exposed to the light you too will get burned and you will likely do serious damage to your eyes. Seriously!

2: UV-C also degrades plastics. Many of these masks and equipment are made of plastic materials and can have reduced efficiency. Specifically the bands will break quicker and parts of the mask may fuse or thin. It also isn't guaranteed that you covered the entire surface of the object. Masks are opaque and have folds in them, thus meaning there is non-uniform exposure. That's why countries are using these methods as a last resort. Even if we can say that these methods certainty kill the virus (there's no reason to believe it wouldn't), there's the question of quality control. How strong is the mask after? And how efficient is it after?

All water treatment plants do not use UV.

It is actually fairly expensive.

Some municipalities only use chlorine. My municipality only has a 40 day supply of chlorine to treat the water.

For such reasons, I purchased a whole-home UV-C water unit.

Now, the wastewater plant uses UV-C, but its output is cleaner than the drinking water input (river).

Can also use ozone. One of Toronto's plants uses it and treats about 20% of the city's water. Nice thing is that you don't need railcars to arrive with it.

https://www.toronto.ca/services-payments/water-environment/t...

And I believe a byproduct of UV irradiation is the generation of ozone.

Any idea on cost? I just looked for a whole home system and it is several thousand dollars.

> I purchased a whole-home UV-C water unit.

Got a link for the system you use?

I just searched Amazon, ‘whole home uv water’, and it was around $200 and does 12gpm.

In your experience, what is the service life of the UV light source for your system?

The manual said 1 year, and the ac adaptor/ballast has an LED status light to indicate power and bulb failure.

It's not just Chinese hospitals that are using UVC to sterilize masks, I think some US hospitals have started doing the same thing due to the shortage there.

This is being pioneered in Omaha:

https://www.unmc.edu/news.cfm?match=25283

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