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Comment by amluto | Hacker News Reader

This seems like a stretch. Barring some rather unexpected effect, this device will not change the amount of aerosolized pathogen emitted by a person. At most it will change the distribution — the aerosols will be presumably be mixed into a larger volume of air. So maybe they will spread somewhat father, but, if so, they’ll be more dilute.

[0] To the extent the wearer’s breath is sucked back through the filter, the total emitted pathogen load will be reduced.

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It is not a stretch. This is why many hospitals require staff to wear an N95 (a hard shell mask—not a surgical mask—in order to prevent as little leakage as possible) underneath a PAPR. PAPRs (with the exception of the CleanSpace Halo if using a special adapter) do not have source control. (I personally use an Optrel e9000x PAPR with an N95 underneath for source control. If not able to use a PAPR such as on an airplane, I wear a valve-free P100 mask [MSA Advantage 900] over an authentic KF94 mask [see: https://behealthyusa.net/ for KF94]. Yes, I am immunocompromised...)

This Dyson device does not have source control, and yes, it is a super-spreader device.

There is proof that such devices are super spreading tools: hospital administrators wore a blow up costume in to a Kaiser Hospital ER and caused a huge COVID-19 outbreak.

This was when contact tracing was in effect in California.

See: https://www.nytimes.com/2021/01/03/us/kaiser-san-jose-outbre...

Comments on r/Medicine subreddit: https://old.reddit.com/r/medicine/comments/kpjs8s/inflatable...

> This Dyson device does not have source control, and yes, it is a super-spreader device.

By this standard, my unmasked mouth is a super-spreader device. (Of course it is! Most super spreader events occurred without the assistance of any particular technology except perhaps walls and a ceiling. Sometimes technology is involved. For example, COVID pretty clearly spreads through inadequately filtered HVAC systems, but that seems to be just because it moves air to people that otherwise wouldn’t have gotten there.)

> There is proof that such devices are super spreading tools: hospital administrators wore a blow up costume in to a Kaiser Hospital ER and caused a huge COVID-19 outbreak.

What proof? I see no evidence whatsoever that exactly the same superspreader event wouldn’t have occurred with the same infected person without the suit.

The issue is that the Dyson device aerosolizes exhaled breath, including virus particles, immediately, and at much higher pressure than HVAC.

As for the inflatable costumes incident there was contact tracing in effect in California when this happened. This was in a Californian hospital and no other incident like this happened before. This was due to the aerosolizing of the costume wearer’s COVID-19 infected breath.

This comment should NOT be downvoted. We are not comparing this device to somebody wearing a mask. We're comparing two mask-less people - one with, one without this device. In which case the quantity of virus expelled in their breath is equal, but the distribution of air is different. How this affects spread of disease is far from obvious.

It could spread more:

- it reaches more people

- it reaches people faster

It could spread less:

- much more diluted

- will dry droplets faster

- it works as a portable filter which filters part of the volume of air in that space

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