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204 points XzetaU8 | 16 comments | | HN request time: 1.995s | source | bottom
1. peanut_merchant ◴[] No.44414951[source]
Not well versed in the field, what are the basic implications of this for health?
replies(3): >>44414976 #>>44415003 #>>44415304 #
2. whitexn--g28h ◴[] No.44414976[source]
The article does not come to any health conclusions, just studies the impact on indoor air chemistry.
3. PaulHoule ◴[] No.44415003[source]
In the 1970s there was a lot of talk about ‘healthful negative ions’ and a fad for negative ion generators even though many of those also generated hazardous ozone.

Hydroxyl ions are a significant kind of negative ion in the atmosphere and they’re known to be good because they react with and clean out pollutants like methane

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

https://earthobservatory.nasa.gov/images/144358/detergent-li...

replies(3): >>44415174 #>>44415293 #>>44415452 #
4. thaumasiotes ◴[] No.44415174[source]
How can something be a negative ion generator without simultaneously being a positive ion generator?
replies(2): >>44415219 #>>44417733 #
5. giantg2 ◴[] No.44415219{3}[source]
.
replies(1): >>44415296 #
6. westurner ◴[] No.44415293[source]
FWIU hydrogen plasma in water for hydrolysis would produce OH Hydroxl radicals. (and H2O2, O3 (Ozone), and NO_x).

TIL that Hydroxyl ions bind to methane and thereby clean the air?

Air ioniser: https://en.wikipedia.org/wiki/Air_ioniser :

> A 2018 review found that negative air ions are highly effective in removing particulate matter from air. [6]

But the Ozone. Ozone sanitizes and freshens, but is bad for the lungs at high concentrations.

7. rpnx ◴[] No.44415296{4}[source]
That isn't how chemistry works.
replies(1): >>44415457 #
8. GeoAtreides ◴[] No.44415304[source]
if only there was a 'Discussion' section in the article, that goes over the basic implication of the study results... if only.
replies(1): >>44415462 #
9. ryukoposting ◴[] No.44415452[source]
Here's some more research, since I have a tiny ozone generator in my fridge and I got worried:

Ozone concentrations as low as 70ppb are hazardous when you're exposed to it for several hours [1]. Estimates for Ozone's olfactory threshold aren't trustworthy, since you go nose-blind to it pretty quickly [2], but it seems like it's probably around 20-40ppb before olfactory fatigue sets in [3,4].

My takeaway is that Ozone generators for rooms/basements/etc are definitely a bad idea. The best-cited olfactory thresholds are all in the same order of magnitude as that 8-hour hazard threshold, and with nose-blindness being a significant factor, you just don't want to mess around with that.

Inside a fridge, though? As long as you don't actually smell any ozone when you open the fridge, and you don't just shove your head in the fridge for hours on end, I'd think you're probably fine.

[1]: https://ozonewatch.gsfc.nasa.gov/facts/SH.html [2]: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-H... [3]: https://www.cabidigitallibrary.org/doi/full/10.5555/19602703... [4]: https://spartanwatertreatment.com/ozone-safety/

10. wizzwizz4 ◴[] No.44415457{5}[source]
Isosaccharinic acid has the same chemical formula (C6H12O6) as glucose, which isn't acidic. However, they both have the same net charge.
replies(1): >>44415516 #
11. braaileb ◴[] No.44415462[source]
Yeesh, who taught you to debase others.
12. xvedejas ◴[] No.44415516{6}[source]
When something is an acid, it dissociates into both a positive ion H+ and negative ion (rest of the molecule)

HA ⇌ H+ + A-

13. gsf_emergency_2 ◴[] No.44417733{3}[source]
You're right but a lot of times the positive ion is far less reactive and/or more massive than the negative ion. Not so much for OH-. Charge is not the only thing that matters.
replies(1): >>44418738 #
14. thaumasiotes ◴[] No.44418738{4}[source]
Well, in a similar way to how you can't generate a negative ion without simultaneously generating a positive ion... how do you use the negative ion in a reaction without simultaneously using the associated positive ion in the same reaction?
replies(1): >>44421398 #
15. gsf_emergency_2 ◴[] No.44421398{5}[source]
Here's one way

https://en.wikipedia.org/wiki/Ion-exchange_membrane

Another, that you might be interested in, but it's more confusing

https://en.wikipedia.org/wiki/Proton-exchange_membrane

replies(1): >>44422258 #
16. gsf_emergency_2 ◴[] No.44422258{6}[source]
See the figure

https://www.fuelcellstore.com/introduction-ion-exchange-memb...

Each ion of salt participates in a different reaction