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?)
I was in one of these kitchens 10 days ago in Uganda, and I sat low to
the floor because higher up was so horrible. But being in such a
setting even for many hours would only equal the equivalent of half of
one cigarette that is inhaled per day. BUT THAT CONSTITUTES THE FOURTH
WORSE HEALTH HAZARD FOR PEOPLE IN THE LEAST DEVELOPED COUNTRIES.
3. And from the above, can we say the following:
Improved biomass-burning cookstoves need to be soooo clean burning that
the air in the kitchen should cleaner than that of a kitchen in which
only 10? or 5? (or 2? or how many?) cigarettes are smoked per hour.
Of course the number will vary depending on the openness or
enclosed-ness of the kitchen.
Another way of saying the same thing: When the current technology
/equipment for testing stove emissions is in use (such as for 75
minutes, which is 30 minutes to boil plus 45 minutes for simmer), what
would be the equivalent of passive smoke from how many cigarettes that
would equal the Tier 0, 1, 2, 3, and Tier 4 levels? Think of this a one
person smoking (exhaling smoke) under the hood of the equipment.
I think that these comparisons can be useful, but only when we have some
numbers will we be able to see if the info is useful.
Paul
Paul S. Anderson, PhD aka "Dr TLUD"
Email: [email protected] Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.com
On 6/4/2013 5:40 PM, Kirk R. Smith wrote:
At 02:30 PM 6/4/2013, you wrote:
Thank you to Kirk Smith for his reply (below for all Stove
Listmembers to read).
I think someone told me that <2.5 PM cannot be seen. But if there
is a lot of it, is it visibly detectable (like the haze of a smoky
room, or is that just the larger particles that we are seeing?)
yes, but the coefficient of haze measured in outdoor settings is
highly correlated with PM2.5, but only if adjusted for humidity.
Related question: For a small child besides it mother in a smoky
cooking shack, cooking "typically" 2 - 3 times per day, what is the
"equivalent" as expressed in cigarettes smoked per day? And
can that be expressed as equivalent of SECONDARY smoke from being in
a room with smokers in it (but that becomes confused because of room
size and number of smokers in it)?
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.
All this is laid out in some detail in my book "Biofuels, Air
Pollution, and Health" (Plenum, 1987)/k
I am trying to visualize this as a mother/cook smoking cigarettes,
and as a baby or a 2-year old child smoking cigarettes (an unnatural
but powerful visual image).
Paul
Paul S. Anderson, PhD aka "Dr TLUD"
Email: [email protected] Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.com
On 6/4/2013 9:15 AM, Kirk R. Smith wrote:
Quick responses below
At 06:27 AM 6/4/2013, Paul Anderson wrote:
Stovers,
Please tell me or direct me to an explanation of the impact of the
PM that is BETWEEN PM 2.5 and PM 10.
I believe that the experts say that under 2.5 is the bad stuff for
respiratory health, and that over 10 is not sufficiently important
even to be measured.
Yes, material over PM10 generally is caught in the upper respiratory
system (nose, etc) and does not penetrate the body sufficiently to
be a health hazard. May be a nuisance, of course. Major reviews
of health impacts, however, show that the fine fraction (less than
2.5) is the best single indicator for health, but that the coarse
fraction (between 2.5-10) also shows effects. Thus, no agency has
abandoned PM10 regs, but most are moving to add PM2.5 regs as well.
Issue for measurements right at the combustion source is that nearly
all is PM2.5.
Is PM size 10 to 25 (twenty five) ( 50 or 100) "visible"?
Detectable to the nose or eyes?
yes, which is a reason that perception is not a great indicator of
hazard
What causes cataracts?
not known for sure, but probably from internal, not external
exposure to combustion-related pollutants in any case. Chemical
carried to the eye through the blood. Eye is well protected
externally. Need to think of PM2.5 as the best indicator of a
mixture, not that itself causes all effects. Like "tar" for
cigarettes, which is essentially PM2.5
How important is the PM larger than 2.5?
See above.
Please forward this inquiry to the stove-medical people who are not
readers of this Listserv.
Paul
--
Paul S. Anderson, PhD aka "Dr TLUD"
Email: [email protected] Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.com
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