From: James Cameron <quozl@laptop.org>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Wed, 23 Dec 2020 14:40:28 -0800
Subject: Re: [OT] Air quality, Dust, TVOC?
Thread-Topic: [OT] Air quality, Dust, TVOC?
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On Wed, Dec 23, 2020 at 02:42:48PM -0500, Jason White wrote:
> Hi everyone,
>=20
> I have taken an interest in measuring and reducing the airborne dust
> levels in my basement. (I suffer from dust allergies)
>=20
> On a whim I've bought a cheap Chinese air quality monitor, a "Yvelines
> HTO-131." I figure it would be neat to try to measure dust levels before
> and after doing a variety of different things clean up the air.
>=20
> This monitor claims to measure:
> * Total volatile organic compounds (mg/m3)
> * Formaldehyde (mg/m3)
> * PM10 (ug/m3)
> * PM2.5 (ug/m3)
> * CO2 (ppm)
>=20
> I'm not sure how relevant most of the parameters, like TVOC, are to dust
> allergies.

They can be correlated sometimes, but not always a cause.

In my own experience, air humidity and suspended sea spray also plays
a significant part, which I guess is because it changes cilia and
mucociliary clearance (MCC) in respiratory tract.  I live 400km from
the sea.

Also in my own experience following brain surgery, suboptimal T3 or T4
hormone levels led to weakened efforts by cilia until supplementation
began.  So if you have any known or undiagnosed thyroid function
issues, get them worked.  Aging also slows cilia, and smoking damages
them.  If symptoms take many hours to begin, suspect an MCC loading
problem.

Check for mould spores; four to 20 microns, blocked by HEPA.
Developing an allergic response to spores can make it look like you
have an allergy to dust in general.  I don't know how to measure mould
spore density.  If symptoms go away in a bleach-cleaned and ventilated
bathroom, and rapidly begin on exit, be suitably suspicious.

> I was wondering if anyone has had experiences with these types of
> monitors and with improving "air quality" in general?

We have a retail air filtering appliance with a display which spends
half the time showing either PM2.5 or VOC.  During dust storms or
bushfire smoke events, we run it to relieve symptoms.  The symptoms
only correlate to the PM2.5 display, not the VOC display.  The VOC
display is really good at detecting farts.

--=20
James Cameron
https://quozl.linux.org.au/
--=20
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