Re: how can one count dust, or particles per volume?

"information_person" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> Hello,
> 
> Here is a weird question, I always wanted to know how many particles are in
> the room I breathe.  IN other words are there analytical methods one can use
> to determine the amount of solid particles in a volume of air (1 cu ft)?
> 
> I want to know how much dust is floating around in a given volume at a
> specific time slice?
> 
> That "may" mean addition and quantification of the following particles in
> air in a typical room.
> 
> i) pollen particles
> ii) bacterial particles
> iii) virus particles
> iv) yeast particles (fungii + mould)
> v) dust (maybe dead-skin, road paint, fluff, and other stuff)
> vi) parasites (flea's?)
> vii) vapor (moisture / water spheres)
> 
> Mainly dust particles probably is sufficient, and I guess
> bacteria, virus, pollen together ?
> 
> Can we somehow count all this ?  and how ? pass 1 L of air through a straw
> and let
> the laserbeam count the particles?  or use petri dishes to quantify microbes
> ? or
> what else can be done.?

I remember my father measuring dust about twentyfive years ago with an
a pump sucking air through an electrostatically charged cellulose
nitrate filter. This was supposed to hold back all particles. Weighing
or burning the cellose nitrate, then weighing gave mass percentages. I
guess if the dust was examined optically/microscopically, quantities
should be available too.
Sorry.. that's all I remember.