[Stoves] Health protective environment and solid fuel burning devices

Sun Jun 4 04:11:54 CDT 2017

Philip:

Back 15-odd years ago, Kirk Smith did the initial BOD calculations for IAP
by assigning (assuming) a national "ventilation factor".

Then came the "PM2.5 equitoxicity" wave and new "data" (rather, estimates)
of ambient air quality from air quality monitors - and later from
satellites -- so he switched to the term Household Air Pollution (HAP)
indoor and outdoors, to properly allocate the Blame of Death (which is
really what BOD ought to be called, not Burden of Disease).

That's as far as the IHME GoBleDygook goes -- estimates, not findings.

But there is a pernicious manner in which the "global" stove enterprise has
surreptitiously slipped in TSF - Three Stone Fire - as the baseline from
which "clean cookstoves" are to be measured. Just how this conspiracy - or
stupidity - developed, I cannot tell (just like blaming only fuel PM2.5
emissions). My suspicion is, the WHO "database" was cooked up with
assigning fuel quantities and emissions to all household users (based on
census and DHS), emission factors for which were based on Kirk Smith's
measurements of unvented TSF emissions.

Remember, for Smith and WHO, "solid fuel use" as claimed in census or DHS
was only a "practical surrogate" for "dirty cooking". For a crude
approximation at the national or global level, it's understandable -- if
one has to pick numbers to please the peer-reviewers -- to say "TSF is the
baseline, with 2 tons of wood-equivalent per year and emission loads of so
much CO, PM2.5".

It all gets comical - or tragic - when such assumptions form the basis of a
drive to lower the Burden of Disease and quantify it.

In my memory all around the world, I have seen fixed and portable stoves,
with and without chimneys, wherever I have seen permanent (masonry, brick,
even wood-and-mud) dwellings. TSF, by contrast, is the choice of homeless
and transient populations.

It is a gross insult to the cooks -- and the masons, home-builders -- that
chimneys and ventilation generally is not talked about in stove design
discussions.

Oh, well. As Anand Karve pointed out a few months ago, some donor project
demanded NO USE OF CHIMNEYS because, the holy cardinals of environmental
health cult said, it only puts pollution outside. Without a thought about
concentrations, exposures, durations.

Make no mistake, there is a mindless war against solid fuels.

Nikhil

------------------------------------------------------------------------
Nikhil Desai
(India +91) 909 995 2080
*Skype: nikhildesai888*

On Sun, Jun 4, 2017 at 12:39 PM, plloyd at mweb.co.za <plloyd at mweb.co.za>
wrote:

> Dear Crispin,
> You express surprise that there is little discussion of vented or hooded
> stoves here. I hadn't thought of that, but it's true and indicative of lack
> of thought.
> A chimney provides draft. If you want a clean stove, you must get enough
> air controllably into the fire. That means relying only on the stove height
> to provide the buoyancy required will probably mean low air flow unless the
> fuelel is large. And a large fuel pyrolyses slowly, making more smoke.
> The alternative to a chimney is to provide a forced draft with e.g. a fan.
> Holding will help remove particulates, but will have no impact on the fire
> dynamics/chemistry.
> Philip
> Sent from my Huawei Mobile
>
>
> -------- Original Message --------
> Subject: Re: [Stoves] Health protective environment and solid fuel burning
> devices
> From: Crispin Pemberton-Pigott
> To: Stoves
> CC:
>
>
> Dear Tom
>
> Answers to a few of your questions interleaved.
>
> Nikhil,
>
>
>
> The first question is really about what policy impact health metrics have
> on cook stoves development and dissemination.
>
> The first question is cooking performance as the stove and fuel and
> operating sequence are critical to acceptance.
>
>  We agree that improving cook stoves for solid fuels has health benefits.
>
> Yes, if 'improved' reduces exposure to all emissions produced during
> cooking. The easiest ways to lower exposure are chimneys and hoods. ‎It is
> interesting that nearly no discussion on this site is about converting
> unvented to vented stoves.
>
> You disagree specifically with the use of DALYS as a measure.
>
> Away from public eyes and ears, many people diss the whole concept of
> DALYs.‎
>
> How would removing DALYS affect change how cook stoves are developed or
> disseminated? Does it matter? Would it change how 160 or more programs
> around the world are funded?
>
> Absolutely, especially it would affect funding going forward. In general
> there is a plan to use claimed aDALYs as a guide ‎to funding levels. To do
> that they need to make policy managers to believe an emission rate leads to
> avoided illness and death for *that* family.
>
> Most stove program benefits are probably not recorded in deaths but in
> incidence of respiratory and related disease.
>
> The plan is to change that. I respiratory and related disease are
> estimated, not measured as was the case in Kyrgyzstan. In the Malawi case,
> the study showed no significant change in the incidence of certain diseases
> in children, something long claimed would be the result of someone buying
> an improved. They blamed outdoor air pollution, stove stacking and other
> factors. In Kyrgyzstan a strong effect was noted without changing the fuel
> and without any effect ‎from outdoor air ingress.
>
> It is very likely the modeled disease response to a change in the PM2.5
> emission rate is unreliable. The measured impact, instead of an estimated
> impact, is inconsistent. This undermines the monetization of DALYs and
> suggests, that improved combustion, chimneys and proper installation are
> key to reducing exposure and changing the disease response.
>
> The best response so far was achieve without changing the fuel.
>
> International working groups on household health and indoor air quality
> examine a long list of diseases and conditions associated with smoke, not
> just mortality. Respiratory diseases alone should be enough to drive policy
> without being overly concerned with numbers generated from estimates of
> mortality.
>
> Yes but, that is not how IHME works. Ditto the GBD estimates.
>
>
>
> Are you saying that we shouldn’t spend money on measuring and modeling
> disease from cooking?
>
> No one is saying that. I am saying it is essential, and that BS-modeling
> is misleading and a waste of money‎. Whatever is done, an emission rate
> cannot by turned by models into a disease response rate.
>
> Who is spending the money?
>
> World Bank, Shell, GIZ, DfID, Norway, Sweden, UNHCR, China, Mongolia,
> India, Indonesia, ESKOM, GACC, not USAID last time I checked.
>
> I understand that European and other countries, not the US, are the major
> donor to stoves development programs.
>
> USAID got badly burned using the WBT in Uganda in 2008 and swore off
> stoves. GIZ swore off solar stoves in 2005 following the ending of the
> North-West project in South Africa. UNHCR uses a lot of ethanol stoves and
> is looking at wood stoves right now.
>
> Do they care about estimates based on DALYs or on some other combination
> of measures?
>
>  That is supposed to start any day. It needs to be stopped before more
> damage is done.
>
> I agree that premature or even mature mortality from smoke would be
> difficult to determine. How good are general statistics? We may never have
> good statistics on actual deaths caused by smoke related diseases.
>
> Correct. It is estimated.
>
> [snip]
>
>
>
> The tier system for cooking stoves appears to be different. There does not
> seem to be an “acceptable” threshold for different types of stoves (solid
> fuel, pellet, coal, lpg, biogas, etc.). It seems to reward only higher
> performing stoves.
>
> In practice the existence ‎of Tier four has seen donors refuse to support
> anything below that. The assumption is that the 'best' stove will provide
> the maximum health benefits. Funding has been provided on the basis of
> preventing health harm. Harm cannot be quantified if there are confounding
> factors, which is most of the time.
>
>  People feel they are at a disadvantage if their stove is not in the
> highest tier. How real is that? Is that the money issue?
>
> Yes.
>
> What is it worth to a stover? Selecting stoves according to tiers is a
> policy decision. Would changing the testing conditions change the results
> for the stove producer?
>
> Definitely as people build stoves to exploit the test protocol.
>
> There is also an assumption in many arguments on this list that stove
> performance is the only criteria for selecting which stoves to support.
> When I speak with donors I get the impression that is not the case and that
> they take a more comprehensive approach when selecting stove programs to
> support.
>
> Only some, and it is often not relevant to the users' opinions.
>
>
>
> Is the tier system over-kill?
>
> For emission rates it is meaningless and misleading. For the WBT metrics
> it is misleading. ‎The worst problem for the ISO was the insistence that
> the tiers by placed inside the Standard which cost the process more than a
> year fighting against it.
>
> Consumers in low and middle-income countries now have more choices of
> stove models. They don’t seem to select models just based on tier ranking.
>
> Tier rankings are not known to the consumers and they are not very
> relevant in any case. The rankings are based on WBT tests which are not
> predictive of performance so why would customers use them? We found word of
> mouth is the main guidig factor, and public wet demos (cooking food).
>
>  A self-supporting stove producer in Central America recently announced
> that they had now produced 30,000 stoves, which suggests that consumers
> select the stoves because they are functional and they like them. The
> stoves are basic designs that employ good combustion practices and are
> tailored to local foods and habits. What is wrong with “good enough.” What
> is “good enough” and how do you measure it?
>
> Good enough is a perfectly acceptable approach especially if it can by
> done at scale. Typically they are  ‎tier 2 on a WBT evaluation for that
> doesn't mean much. Stove programmes won't support a Tier 2 when the Tier 4
> exists, even if the emissions Tier 2's are much more usable and likely to
> be used most of the time.
>
> Shouldn’t we be concentrating on making solid fuel stoves that are  ”good
> enough” to substantially improve health rather than meeting an arbitrary
> standard?
>
> You cannot improve health without a coherent health improvement strategy.
> Stoves are not cures or medicaments. A better stove, especially one with a
> chimney, lowers risk. They might improve health. The difference is not
> subtle.  The guarantee is not there. ‎You can't sell what is not there.
> In some locales, saving half the fuel is much more important than cutting
> out half the smoke. I favour both. Customers often don't care about one or
> both of those metrics.
>
> Regards
>
> Crispin
>
>
> Tom
>
>
>
>
>
>
>
>
>
>
>
>
>
> *From:* pienergy2008 at gmail.com [mailto:pienergy2008 at gmail.com] *On Behalf
> Of *Nikhil Desai
> *Sent:* Saturday, June 03, 2017 12:18 PM
> *To:* Tom Miles <tmiles at trmiles.com>
> *Cc:* Discussion of biomass cooking stoves <stoves at lists.bioenergylists.
> org>; Crispin Pemberton-Pigott <crispinpigott at outlook.com>
> *Subject:* Re: [Stoves] Health protective environment and solid fuel
> burning devices
>
>
>
> Tom:
>
> Thank you for your comment and question what health metric I would propose
> for cookstoves in developing countries. (Short answer: None. An emission
> rate metric is not a health metric.) I have three other incomplete
> responses to your questions and prodding, but let me get to this first.
>
>
> Please suggest what new literature I ought to be reading for determination
> of DALYs for the Global Burden of Disease.
>
> You are correct; the Guatemala and Kenya papers are old. The Nepal and
> Malawi papers are not. In any case, my argument is not with little one-time
> studies with small samples here and there. I have no doubt smoke leads to
> ill health; I think our ancestors in caves had figured that out, without
> multi-million dollar research expeditions with results of no predictive
> value.
>
> Let's take the 2015 GBD. Some 55 million people died; they had lived some
> 30 trillion hours and consumed some 5 trillion meals and beverages, say 3
> trillion of which were cooked on solid fuels (consider that all premature
> deaths are people who died before age 86, so those who died at ages 70-86
> surely had more of their early meals cooked on solid fuels).
>
> What data do IHME have on the emissions, concentrations, exposures,
> disease incidence, or causes of death for the 55 million individuals'
> health damage from 3 trillion meals?
>
> NONE. ZERO. IHME is not about evidence. It is about creating model
> estimates (wilfullly?) based on modeled assumptions based on model
> estimates based on modeled estimates based on ... well, you know the game.
>
> I think I rubbished the GoBbleDygook in one paragraph. Please read Kirk
> Smith ("Millions Dead" 2014) if you have any doubts. With a disclaimer he
> does not make - for the assumption of equitoxicity. After decades of work
> measuring all kinds of organic toxins in some fuel smoke - but not food
> smoke, as if he was intent on demonizing fuels - that he still calls
> equivalent of 400 cigarettes, he has given into the assumption of
> equitoxicity. That essentially makes his judgements fuel-free and
> stove-free, because emissions depend on both fuel and stove, both of which
> vary considerably around the world. Let's wait on that discussion another
> time.
>
> Or please ask WHO to provide the data for last 86 years, even 8.6 years,
> on all these parameters. Direct measurements, not modeled estimates.
>
> And also ask WHO to name 4,000 individuals of the 4 million in that 2015
> cohort that allegedly died prematurely as a result of exposure to Household
> Air Pollution.
>
> How about 400 names? Also 400 from those who died post-maturely but still
> had been exposed to HAP (as nearly everybody over age 86 would have been)?
>
> WHO has no premature mortality data, and can't have any. Premature
> mortality is a population attribute assumed by experts. Even though far
> fewer people in the developing world died after age 86. Nearly all deaths
> in the developing countries are thus premature deaths, and because
> infectious diseases kill fewer and fewer people, all these premature deaths
> have to be blamed on something.
>
> Even Kirk Smith has taken to reporting GBD estimates as DATA.
>
> No, sir. Model output may well be garbage depending on what you feed the
> model; a model is not Mother Cow producing milk from feed.
>
> Estimates are estimates. Absolutely challengeable on grounds of data,
> assumptions, and theory.
>
> Now to your charge - "You haven’t described what health metrics you would
> propose to use in developing countries."
>
> I assume you mean health metrics for cookstoves.
>
> The answer is simple - NONE. Stoves are for cooking, not saving lives, no
> matter how much jumping and screaming is done that chulhas are death
> traps.(Yes, in India, stoves are used as death traps to kill women or for
> them to commit suicide. I don't think Hillary Clinton cared to save those
> women.)
>
> What health metric do you have in the US for cookstoves? What authorizes
> EPA bandits to go around preaching the world something it doesn't have in
> the US? I doubt EPA has the legal authority yet to even incorporate the ISO
> TC 285 stove standards and testing methods or to designate ARC as an
> ISO-compliant testing facility for cookstoves.
>
> (The sheer idea that some 500 million household cookstoves in the
> developing world can be regulated like fans and lightbulbs seems rather
> queer to me. But who knows, poor people will take to them like CFLs.)
>
> No stove produces health or illness, just as PM2.5 pollution is not an
> inherent property of fuels. (There are PM2.5 emissions from foods being
> cooked; after all, they are also biomass with gaseous output at high
> temperatures. Find me studies that separate fuel emissions from food
> emissions, or report disease incidence from smoke on people who go hungry
> half a day every day.)
>
> This whole WHO business of associating hourly emission rates of PM2.5 with
> DALYs is a charade. A fraud. With all its limitations, GBD is an estimate
> of DALYs - for the cohort dead, no matter what the data - attributable to
> different risk factors.
>
> As Kirk Smith cautions, attributable is not necessarily avoidable. Most
> illnesses are attributable to multiple risk factors, whose quantified
> influence is estimated at the population level, not individual level.
> Controlling one risk factor has indeterminate consequences for disease
> incidence, when other risk factors become more important.
>
> Please tell me what you find objectionable in this.
>
> Now to your mention of stoves and boilers air emissions regulations in the
> US. I studied the history of power plant and industrial boiler New Source
> Performance Standards, fuel bans, location controls, and "bubble" from
> around 1966 to 1996. Here is where I think you are wrong in comparing that
> history to cookstoves in developing countries:
>
> 1. You say "until minimum acceptable levels were determined for different
> types of appliances"
>
> Not true as far as large boilers go. First came the NAAQS. Then the
> identification of non-compliance areas. Then fuel bans or new plant siting
> decisions. Then the NSPS.
>
> The NSPS only applied to NEW boilers. Old ones continued operations, even
> in non-compliant areas. Only when Gina McCarthy approved a State
> Implementation Plan revision for New Mexico coal use did the state come
> into compliance. (This was in 2010, and became the basis for Obama's Clean
> Power Plan.)
>
> Similar story about vehicles and stoves. EPA took 30 years to develop NSPS
> for residential wood heaters and may still be blocked from enforcing it.
>
> If you want to wait 50 years for developing countries to enforce Ambient
> Air Quality Standards, then Indoor Air Quality Standards, then stove NSPS
> that would take another 10-20 years as the old stock is replaced, be my
> guest.
>
> 2. For WHO to meddle into cookstoves, it has to develop an overall
> strategy for making indoor air compliant with its air pollution guidelines.
> You cannot control emissions from new sources of a particular type and
> expect to achieve any definite predictable change in PM 2.5 exposures from
> all sources (dust, landfills, excreta, tobacco, pollen, what not).
>
> WHO Guidelines for Household Solid Fuel Use is one of the nuttiest effort
> at environmental management I ever saw in my life.
>
> It was that - and the underlying facade of science of GBD and BAMG - that
> made my blood boil this time around.
>
> Mark my words -- this is a drive to push solid fuel cookstoves out of the
> reach of the poor.
>
> But it will not succeed. You must push not for some "health metrics" -
> can't be any - but "clean enough" modern cooking options. A cook will buy a
> stove that s/he can optimize the use of with respect to his/her
> preferences, safety from many points of view, time spent on specific task,
> perceived "clean"-ness, finances for stoves and fuels (assume "stacking"),
> and how they "fit" in her "rhythm of life" (daily, weekly, seasonally, when
> she is pregnant vs. has three teenage boys to cook for.)
>
> All of this is context-dependent. To pick some hourly PM2.5 emission rate
> and call it "truly health protective" demeans the meaning of health and
> hence also demeans 3 billion people. It's a nutty conspiracy.
>
>
>
> Nikhil
>
>
>
>
>
> ------------------------
>
> Nikhil Desai
>
> (India +91)909 995 2080 <+91%2090999%2052080>
> *Skype: nikhildesai888*
>
>
>
> On Sat, Jun 3, 2017 at 10:12 PM, Tom Miles <tmiles at trmiles.com> wrote:
>
> Nikhil,
>
>
>
> You are citing some old literature. What recent review articles on cook
> stoves and health reflect the biases that you are claiming? What is the
> actual impact of health risk assessments on funding and dissemination of
> improved cookstoves?
>
>
>
> Emissions from heating appliances (stoves, boilers) were actively explored
> for several years in North America until minimum acceptable levels were
> determined for different types of appliances. New appliances are tested for
> compliance but research organizations, like CANMET and EPA, are not
> searching for maximum achievable emissions. In some areas, where weather
> inhibits ventilation, wood burning in fireplaces and stoves is banned
> entirely to meet ambient air quality standards. Ambient standards are based
> partly on health risk modelling. You haven’t described what health metrics
> you would propose to use in developing countries.
>
>
>
> Tom
>
>
>
> *From:* Stoves [mailto:stoves-bounces at lists.bioenergylists.org] *On
> Behalf Of *Nikhil Desai
> *Sent:* Saturday, June 03, 2017 3:33 AM
> *To:* Discussion of biomass cooking stoves <stoves at lists.bioenergylists.
> org>
> *Cc:* Crispin Pemberton-Pigott <crispinpigott at outlook.com>
> *Subject:* Re: [Stoves] Health protective environment and solid fuel
> burning devices
>
>
>
> Crispin:
>
> 1. Heating stoves come in wide ranges appropriate to the local weather
> conditions and housing structures. Your results are context-dependent.
>
> 2. At the same time, only context-dependent evidence of change in disease
> incidence -- don't call it general "health benefit", which is a meaningless
> term -- matters. "Health protective" is a vague, meaningless term. I have
> said here repeatedly that I disagree with Kirk Smith's claims about "truly
> health protective" -- I disagree with the term and I also disagree with the
> baseless association of "health protective" with hourly emission rates.
>
> I wonder why it has escaped notice that much of the empirical work on
> "cookstoves and health" has been done in areas where long-term,
> high-temperature heating is not required but short-term, low-temperature
> heating is required -- Kirk Smith's project in Guatemala highlands, Dan
> Kammen and others' work in Kenyan highlands, and the other reports we see
> from Nepal (some Johns Hopkins babble a couple of  years ago) or Malawi (we
> discussed this here a few months ago).
>
> Is it purely coincidental that health researchers go find the demonic
> smoke in relatively cold areas, where traditional housing may have less
> ventilation, at least part of the year, and people may have a higher
> prevalence of respiratory difficulties (altitude, climbing up steep) and
> lower prevalence of air pollution other than household smoke, as also lower
> prevalence of some infectious diseases?
>
> It is simply silly - if not deceitful - to ignore geography.
>
> As far as I am concerned, it is up to Kirk Smith and IHME to prove that
> solid fuel emission rates, irrespective of the variations in fuel, stoves,
> and cooking practices, have a quantifiable link to future lifetime
> disability, disease, and death (i.e., DALYs). If nothing else, there is no
> way to track individual exposures to all PM2.5 - from foods,
>
> Such computation of "health damage" cannot be done without regard to the
> demographic, geographic, nutritional characteristics of a cohort - leave
> aside individuals, just statistically. Kirk Smith said so in 1999, then got
> drawn in the "global burden" dogma of "equitoxicity of PM2.5" and
> "integrated exposure response", "no or very low threshold".
>
> Just because WHO has bought into this babble of killing people by
> assumptions does not mean stove designers have to get into a meaningless
> competition to produce quantifiable evidence of "lower disease incidence"
> from "low emission heating stoves".
>
> WHO has raised a red herring. To help get research grants so youngsters
> can be kept busy with mindless modeling.
>
> We have far more serious work to do -"clean enough" stoves that users find
> usable.
>
> Yes, we cannot ignore " the improvement of indoor air quality (or not) and
> ambient (meaning outdoor) air pollution. This is a very important argument
> being made presently in the* funding pool* and we should have a clear
> perspective on what works and doesn't, and what is *fundable* and what is
> not."
>
> We need to educate the funders that there is zero evidence that transition
> to gas and electric cooking over the past 100 years has reduced DALYs and
> that to compute aDALYs from "clean cooking solutions" is a meaningless
> exercise with very weak theoretical foundations.
>
> Poor people of the world being held hostage to opinions of BAMG modelers
> is immoral. We have enough deceit with boiling water. Emphasize how your
> results from heating stove interventions lowering pollutant concentrations
> - with some consistent research on exposures (all pollutants in real life,
> of which household fuel emissions may have been a large component) and
> disease incidence - are the appropriate methods to study cost-effective
> interventions, not this babbler about ISO TC 285 Tier 4 emission rate
> targets.
>
>
>
> Nikhil
>
> Boil blood, not water.
>
> ------------------------------------------------------------------------
> Nikhil Desai
>
> (India +91) 909 995 2080 <+91%2090999%2052080>
> *Skype: nikhildesai888*
>
>
>
> On Fri, Jun 2, 2017 at 7:47 PM, Crispin Pemberton-Pigott <
> crispinpigott at outlook.com> wrote:
>
> Dear Friends
>
> I will be posting, as I find it, information relating to the concept that
> there is a 'health protective' aspect to the lowering of stove emissions,
> the improvement of indoor air quality (or not) and ambient (meaning
> outdoor) air pollution. This is a very important argument being made
> presently in the funding pool and we should have a clear perspective on
> what works and doesn't, and what is fundable and what is not.
>
> Individual perceptions are necessarily partial so through consultation we
> should be able to draw a larger picture.
>
> Because everything cannot be put into a single message I hope readers will
> keep things in mind and add relevant perspectives. The first thing to
> establish is whether improvements in indoor air quality can be achieved
> with current technologies (this is first, a technology question). Here is
> an example of a 'desired result:
>
> [cid:image002.png at 01D2DAB4.468F98B0]
>
> In this region a lot of homes have inexpensive LPB (low pressure boilers,
> hydronic heaters, to Americans) and this is a set of measurements made by
> Fresh Air in comparable homes. The metric is intended to show IAQ (indoor
> air quality). In the control homes, the PM2.5 level was 165, 45 and 62 (24
> hr average, if I read correctly).
>
> In the homes with a higher performance and better constructed LPB (about
> the same price as the usual ones) there is a significant difference,
> 'significant' meaning a difference larger than the limit of determinability
> (LOD) by a factor of 3 (which is a sort of standard, accepted way of saying
> the difference is real which high confidence).
>
> In order to have some way of saying, "This product delivers significant
> health benefits" we have to be able to prove that either the overall result
> (24 average PM2.5) is 'acceptable' or we have to be able to prove that the
> contribution to the total has been reduced a great deal. What I mean by
> that is if the above values of 25 for each of the improved LPB homes is
> only made of cooking emissions (boiled fats etc), smoking indoors,
> shuffling of feet, clapping of hands, combing of hair, outdoor air ingress
> and so on, then the contribution by the LPB is zero. So changing fuels from
> chopped wood to wood pellets would make no difference unless it affected
> the contribution from the ambient air ingress.
>
> We should not casually mix these two reporting 'mechanisms'. There is the
> PM2.5 delivered into the home from the device, and there is the total. We
> cannot look at the total exposure (those are individual exposures, not
> indoor air averages - people wore personal measurement devices) and say
> that it was all from the appliance.  Those are two different things. If I
> put the LPB in a lab, pipe all the exhaust outside the lab, and measure the
> leakage from the appliance, I can quantify the total that comes out. If I
> place that in a home and measure the total in the room or the total to
> which someone is exposed, I do not get the same answer because now the
> leakage is mixed with all the other sourced materials. Are you with me?
> There is the contribution from the device and the total contribution.
>
> A lab test is a good at to isolate the stove's contributions. A field test
> is a good way to show the difference between a home with and without the
> device. Obviously the test conducted in the lab should have the same
> typical burning conditions and fuels as the field test so the difference
> has meaning. There is literally no use testing in the lab and getting an
> emissions number and then taking it to the field to check how that impacts
> the total exposure, say, but operating the stove differently with a
> different fuel. That is nearly useless as a method of producing the
> information needed to inform policy.
>
> To 'inform policy' one needs enough information to decide whether or not
> to support the dissemination of a particular device.
>
> Here is another way of making a comparison of 'performance':
>
> [cid:image008.jpg at 01D2DAB4.468F98B0]
> Baseline CO (48 hrs)
>
> [cid:image009.jpg at 01D2DAB4.468F98B0]
> Improved stove installed.
>
> This is a demonstration that the CO level can be reduced quite a lot just
> by changing the stove. There are very few other sources of CO other than
> the stove however one should not rule out that other cooking appliances may
> be in the home. My home has a dozen different 'appliances' from kettles to
> BBQ. A gas BBQ is a significant source of PM2.5 but not a big source of CO.
> In the second chart the average is a bit less than 10 ppm. Prior to
> changing the stove there were periods of several hours with a value above
> 50, sometimes 100 in other homes.
>
> Important to the discussion is that all these improvements were achieved
> without changing the fuel. It is all coal or dung or wood or (frequently in
> the baseline homes) combinations. Dung burns much better in a dreadful
> stove if it is mixed with crop waste like cotton stalks or wood.
>
> There is a toxin spreading through the stove community which is the claim
> that only gas and certain (but not all) liquid fuels can deliver the
> necessary 'health benefits'.  It is obviously false, based on the above,
> but it is easier to say it than to effectively counter a years-long
> campaign to demonise solid fuels in general using the invalid assumption
> that the above results are impossible to achieve.
>
> If we are going to talk about 'health benefits' we have to talk about the
> whole package and the discussion has to be grounded on first principles.
> Measuring PM2.5 for IAQ purposes has to be analysed correctly.
>
> End of rant
> Crispin
>
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