Subject: Dusts and stuff (was Gasketing etc)

From: [email-masked] (Gene Olson and Chris Wilson)
Date: Mon, 27 May 1996 08:05:42 -0400 (EDT)

>snip
>>As for toxicity I'd be surprised if fiberglass is any better. I remember
>>listening to an old insulator coughing once...eeeeeeeeeee! Sounded like
>>a cross between a coffee pucolator and an asmatic.
>snip
>
>Asbestos has been very misalligned.  There are a few types of the fiber
>that are dangerous, but the majority are not.  This  whole thing has really
>been blown out of proportion.  As to the glass being dangerous, actually
>most any fiber material can be dangerous to ones health if breathed in, in
>large amounts over a long period of time.  Actually most any dermal or
>internal contact with most any chemical or mineral product should be delt
>with, with caution.
>
>John Dach and Cynthia Thomas

Deep Breathing of Fine dusts is not advised in any case.

Wear a good dust mask, Dust plugs up the works.

Re: Silca dust,  In that most of the earths crust is made of the stuff 
and it is virtually everywhere, abject fear at the very mention of this is 
to say the least overreaction.

However:  A recent issue of Science News had an article about silica dust 
from sandblasting or glass grinding.  It seems that when silica is 
fractured the cleaveage planes are left covered with highly reactive 
chemical sites where the bonds were broken during the fracture.

Highly reactive translates as Poison.

In this case the silica absorbs hydrogen. In a moist environment such as 
your lungs, this pulls a hydrogen off a nearby water molecule and leaves 
an OH radical looking for a home.

That means a strong base on the order of LYE deep in  your lungs. Lye 
reacts with fatty acids (you) to form soap, which disolves and washes 
away. 

This helps to account for the catastrophic degeneration of the lung (often
less than 2 years sometimes less than 1) where it seems to have literally
melted away in spots. Normally, stuff like black lung and white lung
diseases take much longer to plug things up because the cilia on the lung
lining pass some the particles back out and into the throat where you
swallow them. Fresh cleaved silica dust is kind of like tossing the cilia
hot rivets to catch. They get scarred or die and stop hauling stuff out.

The Reactivity of the broken silica only lasts for about 60 hours. After
that it just plugs things up like any normal dust.

Gene

Please forgive if you've alrady heard this song. 

 The Studios of Gene Olson and Chris Wilson
   Working in Metals, Stone, Mixed Media
    URL: http://www.cris.com/~mettlewk/