[Stoves] particulate size retention

[Andrew Heggie]

Xavier

I'll take the liberty of reposting your question to Prof Lloyd about how
come the smallest particles are more likely to be exhaled rather than
absorbed through the lung membrane and his good explanation and response
  of a couple of hours ago because I find it gives me a good idea about the
mechanisms but some may miss the post because the subject line contains so
many "SPAM"s

"> Dear Philip,



> OK, thanks for the precisions.

> But don’t the recent studies found, or suspect, that below a certain
size, like below 0.1µ, retention increases since the nanoparticles cross
the cell membranes?

> Not sure I understood right.



> Best,



> Xavier
> "

On Tue, 29 May 2018 at 17:44, Philip Lloyd <plloyd at mweb.co.za> wrote:

> It is difficult conceptually to even think about the mechanism whereby
submicron particles interact with matter. I have suggested to you it is a
question of momentum.  At the sub-micron scale “surfaces” are a moosh of
electrons – that’s all you can see as you approach the surface.  You may be
lucky, and be riding a particle which is looking for an electron, but even
so with that excess of surface electrons you are likely to get repulsed.
Alternatively you may be going fast enough (Boltzmann allows it) to dash
through the Coulomb barrier.



> These probabilities are calculable and lead to low adsorption at less
than 0.5 micron. I’ve given you a mechanistic, Newtonian interpretation,
which is a good enough first approximation. Being more exact gets fun but
some of the approximations you have to make are hairy.



> Hope that gives some clarity



> Philip

Thanks Prof Philip  Andrew