[Stoves] Domestic stoves, air pollution and health ==> Back to basics
Harold Annegarn
hannegarn at gmail.com
Fri Jan 6 04:17:42 CST 2017
Dear Stovers
A) I have been following the debates on stove emissions, health effects
(dallying with DALYs) and carbon climate neutrality with interest, and
varying degrees of amusement and despair at the grave (or jocular)
misrepresentations of science and the scientific method. My interventions,
under a new thread, are intended to go back to basics of science on air
pollution and health. I hope thereby to clean up some of the messier
aspects of recent debates that are based on misconceptions of science.
(Regrettably, I claim no authority to be able to similarly clarify issues
of policy, developmental economics or institutional politics.)
B) As a starting point, a draw your attention to the following article:
*Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine
Particulate Air Pollution*
C. Arden Pope, III
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Pope%20CA%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
PhD, Richard T. Burnett
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Burnett%20RT%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
PhD, Michael J. Thun
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Thun%20MJ%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
MD, Eugenia E. Calle
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Calle%20EE%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
PhD, Daniel Krewski
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Krewski%20D%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
PhD, Kazuhiko Ito
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Ito%20K%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
PhD, and George D. Thurston
<https://www.ncbi.nlm.nih.gov/pubmed/?term=Thurston%20GD%5BAuthor%5D&cauthor=true&cauthor_uid=11879110>,
ScD JAMA. 2002 Mar 6; 287(9): 1132-1141.PMCID: PMC4037163 (Journal of
American Medical Association)
The publisher's full final edited version of this article is available at
JAMA with no paywall:
JAMA. 2002 Mar 6; 287(9): 1132–1141
<https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=11879110>
.
*Abstract*
*Context*
Associations have been found between day-to-day particulate air pollution
and increased risk of various adverse health outcomes, including
cardiopulmonary mortality. However, studies of health effects of long-term
particulate air pollution have been less conclusive.
*Objective*
To assess the relationship between long-term exposure to fine particulate
air pollution and all-cause, lung cancer, and cardiopulmonary mortality.
*Design, Setting, and Participants*
Vital status and cause of death data were collected by the American Cancer
Society as part of the Cancer Prevention II study, an ongoing prospective
mortality study, which enrolled approximately 1.2 million adults in 1982.
Participants completed a questionnaire detailing individual risk factor
data (age, sex, race, weight, height, smoking history, education, marital
status, diet, alcohol consumption, and occupational exposures). The risk
factor data for approximately 500,000 adults were linked with air pollution
data for metropolitan areas throughout the United States and combined with
vital status and cause of death data through December 31, 1998.
Main Outcome Measure
All-cause, lung cancer, and cardiopulmonary mortality.
Results
Fine particulate and sulfur oxide–related pollution were associated with
all-cause, lung cancer, and cardiopulmonary mortality. Each 10-μg/m3 elevation
in fine particulate air pollution was associated with approximately a 4%,
6%, and 8% increased risk of all-cause, cardiopulmonary, and lung cancer
mortality, respectively. Measures of coarse particle fraction and total
suspended particles were not consistently associated with mortality.
Conclusion
Long-term exposure to combustion-related fine particulate air pollution is
an important environmental risk factor for cardiopulmonary and lung cancer
mortality.
|____________
C) The significance of this article for the stove list debates is that:
- It is a primary research article - not a secondary
summarised/re-interpreted version valorised by the WHO.
- It deals with *statistical associations (**Risk Ratios) *between PM2.5
and lung cancer and cardiovascular mortality over a 16 year period for a
study cohort numbering in the millions. It does not claim or explain
causality.
- It presents statistical correlations of *Risk Ratios of lung cancer
and cardiovascular mortality. *It does use the concepts of premature
deaths, a source of heated contestation in StoveList debates. It does not
enter into a discussion of the financial value of life or DALYs.
- The study deals comprehensively with the confounding effects of
smoking - which has a higher Risk Ratio - and mentions in passing other
factors controlled for and which have elevated Risk Ratios for the study
population (e.g. gross obesity (level 3).
- No enhanced Risk Ratio was found in association with PM10 (defined in
the post-2000 sense of particles below 10 but above 2.5-micron diameter).
D) Arising from this, several points of clarity regarding the science:
1. Establishment of Risk Ratios is a property of the *population
ensemble* numbering in hundreds of thousands. This* ensemble property*
of a population cannot be attributed to individuals or small populations of
a few hundred or thousand. Accordingly, taunts such as "Show me one life
that has been saved by a clean cook stove", reveal a perhaps jocular but
nevertheless foolish conceptual misunderstanding.
2. *PM2.5 and EQUITOXICITY* (addressed mainly to Crispin).
PM2.5 is measured as an *INDICATOR* of fine particulate matter (mainly
in urban atmospheres). Scientists and regulators are well aware that fine
particulate matter originates from diverse sources and contains particles
of widely differing physical and chemical composition, and that some of
these species may be more damaging to the human respiratory system than
others. Nevertheless, as an INDICATOR of urban air quality, PM2.5 serves
the purpose of an indicator. (a) It is readily measurable with a moderate
amount of technical skill and commercially available apparatus; (b) It is
applicable across a range of conditions in space and time, allowing for
tracking of trends. (c) The indicator values are easily communicated to and
understood by the lay public. PM2.5 is again an *ensemble property*, and
at a superficial level may one assert that all particles comprising the
ensemble are EQUITOXIC. That some individuals may have used the term
EQUITOXICITY in this sense, is not intended to be taken literally. To rail
against the term is to set up a straw man argument, dressed in funny
clothes designed to scare off the crows.
3. However, when it comes to controlling or reducing sources or PM2.5 in
particular localities, then source apportionment studies are needed, to
establish the relative contributions from diverse sources, that may include
residential wood burning (also in American cities in colder climates),
sulphates from coal combustion, diesel soot emissions. Reductions are
planned and regulated on the basis of cost-effectiveness, reflected in
State Implementation Plans (SIPs) in USA jurisdictions. Source
apportionment plans deal with reducing the concentrations of overall PM2.5,
without going into issues of health effects and consequent economic loss
due to mortality of morbidity - the domain of epidemiologists, not air
quality regulators. In the case of specific high toxicity compounds, such
as asbestos fibres or CrVI (chromium valence 6), other air toxic
regulations come into play quite separately from the generalised PM2.5
control strategies.
On the health effects of various species of particles in the PM2.5
ensemble (often now referred to as nanoparticles), there are significant
advances in the last decade of understanding the modes of interaction
between particles and the human physiological system. One interesting
finding is that some materials are more active (toxic) in the finely
divided nano range than one would suppose from the bulk properties of the
material.
4. Inhalation of and deposition of PM2.5.
Point 2 above leads to the need to clarify misconceptions reflected in
recent stove list discussions concerning the deposition of particles in the
human respiratory system.
Broadly, coarse particles greater than 2.5 microns diameter are trapped
in the upper airways (nose, throat), while fine particles (<2.5 microns)
proceed into the bronchial system. Particles in the range 300 nm (0.3
microns) and less, the bulk of PM2.5 mass, behave similarly to gas
molecules and are carried in the air stream through 18 bifurcations of the
bronchial system to the alveolar sacs. Once in the alveolar region,
governed by laws of diffusion, some of the nanoparticles may reach the
walls of the alveolar sacs and be dissolved or absorbed and transmitted to
the blood stream (e.g. nicotine droplets from tobacco smoke). Insoluble
particles are attached by macrophages (white blood cells) and either
transmitted away by the lymph drainage fluids, or remain in place
eventually forming inflexible fibrous tissue (in advanced cases causing
e.g. silicosis and emphysema). Paradoxically, the very properties that
allowed the nanoparticles to reach the deepest airways, similarly allow the
particles to make their way out of the lungs and to be exhaled. In each
breath, typically only about 60% of particles are deposited, and 40% are
exhaled. For example, a smoker will still exhale detectable levels of
nicotine fumes for ten to twelve breaths after the last puff.
Coarse particles deposited in the upper airways can also trigger
physiological responses - one need only mention the allergic response to
inhalation of pollen grains (typically in size range 5 to 50 microns) that
are trapped in the nose.
E. Arising from this, a personal comment based on my four decades as an
academic research on atmospheric particles. This point addresses ongoing
messiness and confusion in the recent StoveList debates (which is a good
open forum for robust verbal sparring) but more seriously has resulted in
major conceptual confusion in the debates of the international efforts to
devise clean stove evaluation procedures and associated performance
criteria (tiers).
The fundamental error is to try and combine efforts to reduce particulate
emissions from stoves (source characterisation and emission control
measures) with Relative Risk outcomes or, even more remotely, with
premature deaths or DALYs.
1. Stove experts know about stoves, thermal and emissions performance
testing.
2. Exposure modelling and monitoring of stove emissions concentrations
in homes and air pollution in general in the ambient environment are
separate disciplines that do not necessarily fall within the knowledge
domain of stove experts.
3. Correlations between exposure to air pollutants and specific health
outcomes are established by epidemiologists at a population scale. Even
relationships between tobacco smoke and adverse health outcomes took
decades and population-scale studies to establish.
4. Testing for causal relationships (i.e. beyond statistical
correlations) between specific pollutants and human immunological responses
is properly the domain of specialised medical studies.
As professional scientists, environmentalists, developmental economists we
are aware of the broad issues of air quality and public health. However,
when the task was a relatively straightforward assignment: *Develop a
standard method for testing the energy and emissions performance of a
domestic stove designed for cooking and space heating*, it is in my opinion
a grave perversion of sound science, technology and regulation to try and
conflate two or more of the above four stages into a single standard. For
well-intentioned students who approached me to supervise a project on air
pollution and health because they were concerned about the health
consequences of high smoke concentrations (in South Africa from domestic
coal combustion), I had to advise them: I can supervise a study of ambient
concentrations, of the emissions of stoves, or the characterization of
individual particles or bulk particulate matter. However, as a physicist,
environmentalist, geographer, I cannot supervise and I cannot marshall the
resources to do a health based study. If you wish to study health effects,
then you need to be in a medical faculty.
I rest my case.
A similar argument can be mounted concerning the conflation of stove
testing and global soil properties, food security, de/reforestation and
global change, but that may be a topic for a future post.
Best regards
Harold the Sceptic
(N.B. I am a sceptic by vocation and profession, for such is the nature of
science. To those who wish to believe, go the church on Sunday or mosque on
Fridays. On all other days of the week, I will tempt you to doubt, ye even
deny, and ask for the evidence.)
Harold Annegarn
Energy Institute
Cape Peninsula University of Technology
Mobile +27 (0)83 628 4210 Office +27
hannegarn at gmail.com <hannegarn at outlook.com>
hannegarn at outlook.com
On 6 January 2017 at 08:11, Traveller <miata98 at gmail.com> wrote:
> Dear Ron:
>
> Happy New Year!
>
> First, I am DELIGHTED, RELIEVED to read your definition of a "climate
> denier" - "a person with no interest in carbon dioxide removal (CDR)."
>
> I do have megahours of interest in CDR. Just tell me from where, when, how
> much, by whom, at what cost, and where to put it.
>
> I have been doing CDR for all my life.
>
> Thank you, thank you, thank you. Now that I am not a climate denier, I
> don't have to fear going to hellfires or ovens till I die.
>
> It's all a matter of accounting.
>
> ***
> On the other hand, I am sad to see you start out a New Year on a sour
> note.
>
> On Haiti and LPG Webinar, I did address your Comment 1 - "*I don’t think
> many will mind if I reopen the topic." *and Comment 2 - "* I don’t have
> the time now to prove this, but am sure we can find climate denial funding
> coming from this Association. " *I took my cue to reopen the topic from
> you, and I also made some comment on WLPGA. Please don't blame me for your
> neglect to read.
>
> ***
>
> We can continue that LPG thread if you read my replies to Paul and to you
> on GACC and Haiti (more to come). Here I address your "I will respond about
> Kirk when I am told which of hundreds of Kirk Smith writings I should read.
> "
>
> Oh, dear. I don't know what if anything you have read from Kirk Smith. You
> could start with his opinion pieces - "In Praise of Petroleum", "Power to
> the People", and "The Petroleum Product That Can Save Millions Of Lives
> Each Year".
>
> I assume you have read his research on putting carbon gases in the
> atmosphere via traditional biomass combustion (defined as uncontrolled
> combustion of unprocessed solid biomass).
>
> What you may find is relevant to both this thread as well as Paul's
> question on LPG in the Haiti thread about lower GHGs (and one earlier).
>
> Please also tell us just what of Kirk Smith's papers you have read on
> health effects of biomass combustion and quotes that you like. Taking his
> name in vain is intellectual abuse.
>
> In a 6 November 2016 post on this list's thread "LPG versus gasifiers with
> dry biomass", I had cited Prof. Smith's assertion:
>
> "And, as yet, no biomass stove in the world comes close to the boundary –
> is* clean enough to be truly health protective in household use."*
>
>
> He was also reported in a Washington Post item
> <https://www.washingtonpost.com/opinions/these-cheap-clean-stoves-were-supposed-to-save-millions-of-lives-what-happened/2015/10/29/c0b98f38-77fa-11e5-a958-d889faf561dc_story.html> in
> 2015 “As yet, no biomass stove in the world is clean enough to be truly
> health protective in household use”.
>
> I expressed my dissent from this view, but if you agree with it, please
> say so.
>
> Because that means biomass stoving for the last 50-odd years has failed in
> terms of being "truly health protective in household use."
>
> Amen. I was hoping to leave all that in the last year.
>
> ****
>
> Now to the main issue here - biomass power and climate-neutrality.
>
> It is a matter of ideological accounting, not science.
>
> Whoever has a hammer in hand sees nails everywhere. Biochar seems to be
> your hammer.
>
> I have written earlier that I discovered Biochar in 2007/8 and Stephen
> Joseph made me a believer.
>
> Now just tell me your global plan for biochar. I will be a partner in
> Alliance for Biochar Cooking (ABC). GACC CEO can be invited to help.
>
> I did some CDR work 20+ years ago on TVA co-firing of peanut shells in
> Georgia and other biomass power options. I also worked on CCS (Carbon
> Capture and Sequestration) options and putting CO2 in old mines and domes.
> How much CDR did you do?
>
> *****
> Apart from biochar or such projects, taking the earth system as a whole, I
> repeat my assertions:
>
> “*To begin with, biomass is not GHG-neutral. Period. "*
>
> This time I will give you some suggestions to read - Ruddiman
> <http://stephenschneider.stanford.edu/Publications/PDF_Papers/Ruddiman2003.pdf> and
> Unger <http://pubs.giss.nasa.gov/docs/2013/2013_Unger_un02100s.pdf>. Also
> this
> <http://www.humansandnature.org/william-ruddiman-and-the-ruddiman-hypothesis>.
> Prove me wrong.
>
> Water and biomass is nearly there is to understand about human climate.
> But please read Kirk Smith, then we can debate the GHG-neutrality of
> biomass combustion (alone).
>
> “*And if you don't assume that, you leave the field open to any carbon
> from biomass combusted anywhere being re-absorbed in a new tree anywhere." *
>
> This is a scientific truism - that any carbon emitted anywhere may be
> re-absorbed anywhere (tree or not) - and other assumptions are matter of
> accounting. Prove me wrong.
>
> Chemistry is everything. Not counting molecules. CO2 is not a WMD; do ask
> CIA though.
>
> Nikhil
>
> ---------
>
>
>
>
>
>
>
>
>
>
> On Tue, Jan 3, 2017 at 11:43 PM, Ronal W. Larson <
> rongretlarson at comcast.net> wrote:
>
>> Nikhil: cc List and Paul
>>
>> Whew - 5 messages today from Nikhil and finally one that I can see all
>> of on my screen at once. (Here’s hoping I don’t have to read 5 more
>> tomorrow for the third day in a row.)
>>
>> In three of the four others I see one citation - GACC on Haiti. It
>> would help me (and I think others) if Nikhil would keep all of my messages,
>> not selectively pull out of them. (for his GACC2, Nikhil has excised all
>> of my remarks #1 and #3. Why?)
>>
>> I will respond about Kirk when I am told which of hundreds of Kirk Smith
>> writings I should read. I seriously doubt that Kirk has written much about
>> the two cites below covering BECCS and albedo. Note that neither of these
>> have much, if anything, to do with stoves.
>>
>> I don’t have time tonight to refute any of the mostly incorrect and
>> non-pertinent arguments below, but let me repeat one (yNikhil, from
>> below)that could only come from a climate denier - defined here as a
>> person with no interest in carbon dioxide removal (CDR):
>>
>> “*And if you don't assume that, you leave the field open to any carbon
>> from biomass combusted anywhere being re-absorbed in a new tree anywhere." *
>>
>
> I interpret Nikhil to mean that CDR via biochar only makes sense when
>> source and sink are in the same block, county, state, or country, (or
>> continent?) Whew! If not, what then does he mean? (Of course you have
>> to read more below.)
>>
>> In sum, I strongly support Paul’s gentle request to Nikhil to stick to
>> topics that relate to this list - not things again/always in support of
>> coal. And not blame me for not having responded quickly enough to some
>> un-named publication of Prof. Smith (whose work, I repeat, on health
>> matters related to stoves I strongly support - and look forward to learning
>> what I am supposed to dissociate myself from in order to agree that the
>> (9:04 AM CDT) climate-denying material (not in any way stove or
>> health-oriented) below is on-topic.)
>>
>> Last point for Nikhil re his last line below
>>
>
>
>> (“*To begin with, biomass is not GHG-neutral. Period. ")*
>> - does he think that biochar from stoves cannot be carbon negative?
>>
>> Ron
>>
>> ps. I argue these topics (albedo, BECCS, afforestation , etc) most every
>> day - on half a dozen lists - but never on this list.
>>
>> On Jan 3, 2017, at 12:36 PM, Traveller <miata98 at gmail.com> wrote:
>>
>> Paul:
>>
>> It might become on-topic once Ron reads Kirk Smith.
>>
>> Nikhil
>>
>>
>> ---------
>> (US +1) 202-568-5831 <(202)%20568-5831>
>>
>>
>> On Tue, Jan 3, 2017 at 1:05 PM, Paul Anderson <psanders at ilstu.edu> wrote:
>>
>>> To Nikhil only,
>>>
>>> I agree that your message is "Off-topic". Thank you for making that
>>> clear in your subject line. Please do not make more messages that are so
>>> far off-topic that they just are beyond the scope of the Stoves Listserv.
>>>
>>> Thanks,
>>>
>>> Paul
>>>
>>> Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
>>> Email: psanders at ilstu.edu
>>> Skype: paultlud Phone: +1-309-452-7072 <(309)%20452-7072>
>>> Website: www.drtlud.com
>>>
>>> On 1/3/2017 9:04 AM, Traveller wrote:
>>>
>>> Oh, dear. Just because a tree is releasing CO2 absorbed earlier makes it
>>> carbon neutral?
>>>
>>> Then all trees could be harvested, burnt, and that would still be carbon
>>> neutral. I don't think IPCC allows that -- its inventorying methods require
>>> that such "land use change" be reported separately.
>>>
>>> ****
>>> Another way of putting the question (and I think this is implied by the
>>> current methods) is whether the CO2 released will in future be absorbed by
>>> another tree.
>>>
>>> But that raises a different problem -- this re-absorption may take years
>>> and that it may happen somewhere else. Assuming that the Drax carbon
>>> emissions from biomass burning were to be re-absorbed in the US forests
>>> where the pellets came from is quite a stretch.
>>>
>>> And if you don't assume that, you leave the field open to any carbon
>>> from biomass combusted anywhere being re-absorbed in a new tree anywhere.
>>>
>>> Since CO2 from wood combustion in a power plant is no different from CO2
>>> from my breaths or cremation or CO2 from a power plant, it is plausible to
>>> argue that CO2 from Chinese coal-fired power plant is what gets absorbed in
>>> the net expansion of boreal forests in Canada and Europe.
>>>
>>> Aha! But then we have the dilemma of changing the albedo effect. (Reforestation
>>> Doesn’t Fight Climate Change Unless It’s Done Right
>>> <https://thinkprogress.org/planting-trees-climate-change-solution-3e5b6979561f#.jok1faoia>,
>>> Natasha Geiling, ThinkProgress, 31 August 2016).
>>>
>>> Perhaps it's better to trim boreal forests, convert into charcoal, and
>>> export to Nigeria, Ethiopia, DRC.
>>>
>>> Albedo effect, apart, bioenergy capture has another problem - "“But if
>>> you are going to do BECCS, you are going to have to grow an awful lot of
>>> trees and the impact on land use may have very significant effects on food
>>> security,” (Reflecting sunlight into space has terrifying consequences,
>>> say scientists
>>> <https://www.theguardian.com/environment/2014/nov/26/geoengineering-could-offer-solution-last-resort-climate-change>,
>>> Damien Carrington, Guardian (UK) 26 November 2014)
>>>
>>> In short, the CO2 accounting business is riddled with confusion.
>>>
>>> ****
>>>
>>> Deliberate confusion for political purposes. The methods of GHG
>>> accounting are NOT value-free; they (including the choice to use 100-year
>>> GWPs instead of 20- or 50-year GWPs) are intentionally biased. (I was
>>> marginally involved with this 30-odd years ago.)
>>>
>>> The most serious objection to the purported "carbon neutrality" of
>>> "biomass" is that depending on combustion technology, the emissions of
>>> non-CO2 GHGs - methane, which is counted under Kyoto cooking of numbers,
>>> and NMVOCs, CO, which Kyoto does not permit -- are more potent than CO2.
>>>
>>> If you add in black carbon, the non-CO2 damage is significantly higher.
>>>
>>> More so if you use 20-year GWP (my preference for the developing
>>> countries).
>>>
>>> The combined GHG loads from biomass direct thermal use around the world
>>> - when counting all GHGs and black carbon (I can cook up some estimates) -
>>> are in the range of all CO2 from Indian coal-fired power plants, maybe even
>>> all CO2 from Chinese coal-fired power plants.
>>>
>>> So, global warming is due to inefficient biomass use, as much as it is
>>> from India-China coal-fired power plants.
>>>
>>> Surprised?
>>>
>>> Some sages said 16+ years ago, "If one is going to put carbon in the
>>> atmosphere anyway, CO2 is the least harmful species from climate or health
>>> point of view."
>>>
>>> The policy implications of this observation are profound.
>>>
>>> To begin with, biomass is not GHG-neutral. Period.
>>>
>>>
>>> Nikhil
>>>
>>>
>>
>>
>
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