[Stoves] Between PM 2.5 and PM 10

[Jay Smith]

I'm traveling and don't have access to all my files as a result so I can't give you details from when I was actively working on this a few years ago.  There is only 1 study that I could find then that modeled the passive particulates in a house from a certain number of cigarettes being smoked and a typical amount of air exchange.  The levels were actually around the lower part of the range in the group in Guatemala that had the rocket stoves installed.  For cigarette smoke,  we know that this amount of smoking in a household is associated with increased childhood pneumonia.  In the long-run, personal exposure is what counts and this is hard to measure for particulates which is why Kirk Smith's group used personal CO monitors on children instead.  I think it would be useful for someone to mount a large study that paid women to carry a particulate sampling system inside a life-size baby doll to get accurate ranges for what a typical infant is exposed to.  Ideally this would be done in multiple locations where etiologic research on pneumonia in children is being done.  Unfortunately the clinicians doing those large studies did not opt to look at smoke exposure levels; that probably goes along with the mindset that has been encountered in the past from the Gates Foundation that seems to dismiss attempts to lower exposure to combustion products as not as worthy of attention as their efforts to diagnose and treat these pneumonias more quickly and adequately in order to lower the death rate.

Jay Smith, MD, MPH
________________________________________
From: Ron [rongretlarson at comcast.net]
Sent: Wednesday, June 05, 2013 11:36 AM
To: Discussion of biomass cooking stoves; Paul Anderson
Cc: Kirk R. Smith; Discussion of biomass cooking stoves; Hugh McLaughlin; Jay Smith; jetter jim; Dean Still
Subject: Re: [Stoves] Between PM 2.5 and PM 10

Paul, Kirk et al

  Thanks to you both for this exchange.  I only respond to be sure that Paul's first question is answered.  I think that Kirk was not saying that.  He maybe was referring to a standard for PM 2.5

  The second point below contradicts the first.  I truncate most of the exchange except that pertinent to these two items and a third.

   The third is on Kirk's reference to BAP. .  Googling says this is benzo a pyrene - a PAH (polyaromatic hydrocarbon) produced both in cigarettes and wood stoves - some are carcinogenic and probably/possibly/maybe BAP is one of the worst.  I believe these are not now being measured in standard stove testing and wonder if they should be.  Since PAHs are associated with higher temperatures than typically found in TLUDs, might pyrolyzing stoves show up better?

  I add Jim Jetter and Dean Still to get their thoughts as well.  Most likely the best work on BAP will have been done by Kirk and his groups, but he may not have looked at any pyrolyzing stoves.
This probably is an expensive test.

    See excerpt below.

Ron


On Jun 4, 2013, at 10:31 PM, Paul Anderson <psanders at ilstu.edu<mailto:psanders at ilstu.edu>> wrote:

Dear Kirk,

Your reply (below) is quite useful, and I hope the Stovers on the Listserv will read it.   And it leads to further questions:

1. Did I understand correctly?   You say that HALF of a single cigarette per day (directly inhaled) is equal to the PM 2.5 inhaled (as "secondary" smoke in the kitchen) by a cook or child who is in a typically poorly enclosed "smoky kitchen" with a 3-stone fire .   WOW!!

2.  And that a
typical open wood cookfire produces about 400 cigarettes an hour worth of PM2.5
(that I assume can also be inside a poorly enclosed cooking space).   If a person takes 12 minutes to smoke one cigarette, that is 5 per hour for one person.  So the 3-stone fire creates a smoky environment that is the equivalent of 80 persons smoking 5 cigarettes per hour in an enclosed space.   That helps explain the smoke billowing out under the eaves and through the door and cracks of many "kitchens" with 3-stone fires.   (Did I express that correctly?)

    <long snip then Kirk said. - we need explanation of "the levels">

Not an answerable question since small children do not smoke (who knows how much they would breath in if they did).  For an adult, the levels are a about half a cigarette or so equivalent in daily dose (PM2.5 inhaled), depending of course on how polluted the house is.    In terms of secondhand tobacco smoke, a typical open wood cookfire produces about 400 cigarettes an hour worth of PM2.5.    More in terms of some other pollutants, for example BAP.

      <snipped rest>

Ron