[Stoves] Fwd: from K Smith [stove] Smoked out: Coal and health

[ajheggie at gmail.com]

[Default] On Mon, 10 Jun 2013 09:16:41 -0400,"Crispin
Pemberton-Pigott" <crispinpigott at gmail.com> wrote:

>
>Don't deep mined coals have elevated concentrations of everything?

Hardly, they are likely over 90% carbon, depending on how hot they
have been cooked. The thing is that many of the heavy metal salts are
not very soluble, so when the coal was formed in a wet environment
then super heated the superheated water was able to dissolve them, as
it then flashed off as steam the heavy metals were deposited in the
coal seam.

Interestingly I just read today that the fungi that can attack lignin
hadn't evolved at the time the plant precursors to coal existed, so
now it is unlikely coal would be formed from plant residues.
>
>As to what comes out in a fire I leave that to Prof Lodoysamba who watches
>the elements floating around Ulaanbaatar better than anyone. Some metals can
>be evaporated and some cannot.

Yes and it is the conditions in the fire that determine whether it is
oxides, carbonates or other species of heavy metal derivatives are
formed. Presumably it's their volatility in the fire which determines
if they end up as a solid ash or a vapour.


>He expressed a concern about the sudden and
>quite dramatic increase in cadmium this past winter for the first time, the
>root cause of which is still unknown. There is a lot of salt in the air.

Do you mean common salt? It doesn't look like one could get much
further from a sea.

AJH