[Stoves] [Stoves Digest, Vol 81, Issue 21] Another attack on solid fuels by public health adventurers

[Karin Troncoso]

Dear Crispin

The note that you cited fro our paper saying that the Philips stove reduces
PM2.5 concentration by only 66% was a cite of the work by Muralidharan et
al., 2015. It is based in a KPT not in a WBT: “Here, we tested a
traditional clay chulha cookstove (TCS) and five commercially available
ACSs, including both natural draft (Greenway Smart Stove, Envirofit PCS-1)
and forced draft stoves (BioLite HomeStove, Philips Woodstove HD4012, and
Eco-Chulha XXL), in a test kitchen in a rural village of western India.
Compared to the TCS, the ACSs produced significant reductions in
particulate matter less than 2.5 µm (PM2.5) and CO concentrations
(Envirofit: 22%/16%, Greenway: 24%/42%, BioLite: 40%/35%, Philips: 66%/55%
and Eco-Chulha: 61%/42%), which persisted after normalization for fuel
consumption or useful energy. PM2.5 and CO concentrations were lower for
forced draft stoves than natural draft stoves. Furthermore, the Philips and
Eco-Chulha units exhibited higher cooking efficiency than the TCS. Despite
significant reductions in concentrations, all ACSs failed to achieve
PM2.5 levels
that are considered safe by the World Health Organization (ACSs: 277–714 μ
g/m3 or 11–28 fold higher than the WHO recommendation of 25 μg/m3;)”

The objective of our paper was not to support LPG industry, but to show
that LPG subsidies have helped to give access to this clean fuel (clean
from a health perspective) to the poor in countries like Ecuador,
Venezuela, Bolivia and El Salvador. As we wrote, there are many barriers
for the use of LPG, and infrastructure and willingness to use it are some
of them. The paper was not intended to evaluate solid fuels stoves
performances; the proposition is a simple one: some countries in LAC have
been giving subsidies to LPG for many years, what are the results? Do those
countries have less use of solid fuel for cooking than expected? Yes, they
do.

The implication is only that helping the poor to buy clean fuels may be
part of the solution towards universal access to clean fuels.

Until today, there is not a solid fuel stove that reduces exposure enough
as to comply with the WHO guidelines for indoor air quality. It is a high
standard. It is hard to reach. You may choose to believe that it was
settled for some obscure purposes but I believe that they are evidence’
based. If there are new technologies than can achieve dramatic reductions
in PM2.5 exposure using solid fuels, that would be great news,  if you have
evidence like the study from Fresh air and the World Bank to share, I would
appreciate it. I definitely think that the solution it’s not a single one
and it will be a combination of policies, strategies, fuels and
technologies. Targeted subsidies to LPG and electricity may be part of the
solution.

I have been researching adoption of fuels and technologies to cook for the
past 10 years. As part of my work, I have interviewed hundreds of women in
Latin American countries and I have found that the economic barriers
overcome the cultural barriers to the adoption of clean fuels. Many women
have expressed their wish to be able to afford LPG to cook. I think that we
have to keep in mind their wish to have access to the same benefits that we
already enjoy, when considering solutions for the poor.

Best Regards
Karin



Dear Friends

In case there be any doubt as to the nature of the war on solid fuels, here
is a street-legal extract from the paper mentioned below:

?Though the reasons underlying [use of solid fuels] are complex, it has
been shown to be highly associated with poverty and the lack of access to
clean fuels. Access to clean fuels is difficult to address, given that
individuals may not have the financial resources to buy Liquefied Petroleum
Gas (LPG) or electricity, even when available in their communities. For
this reason, most solutions proposed in poor areas have been focused on
?making the available clean? (i.e. to burn biomass cleanly in improved
biomass stoves), rather than on ?making the clean available? (Smith and
Sagar, 2014). On account of a better combustion, improved biomass stoves
have higher efficiencies a lower emissions of kitchen smoke, while still
relying on solid fuels that are accessible and generally free. These new
improved biomass stoves vary enormously, but none have yet been shown to
sufficiently reduce exposure to PM2.5 to comply
with the WHO's Guidelines for Indoor Air Quality (Smith and Sagar, 2014).
Research on exposure-response shows that the use of LPG leads to
concentrations of PM2.5 below the critical level of 10 ?g per m3, whereas
concentrations measurements in homes with improved biomass stoves have
shown an annual average of 170 ?g per m3 (Johnson and Chiang, 2015; WHO,
2014b). Even the Philips stove, the most advanced biomass stove in the
Global Alliance for Clean Cookstoves (GACC) catalogue, reduces PM2.5
concentration by only 66% (Muralidharan et al., 2015). This highlights the
importance of ensuring access to clean fuels and not just improving the
combustion and efficiency of biomass stoves. In LAC 90 million people?

There are a lot of things worthy of comment in this one paragraph.
For a start:
?PM2.5 below the critical level of 10 ?g per m3 ?

What? 10 ?g per m3 is so extraordinarily low that no one will meet it. If
it is true that we are all doomed to expire for breathing air containing
generic PM2.5 above that level, we can give up now.

Who says the Philips stove is the most advanced? Reduced what by 66%?
Exposure? Against what baseline? In who?s kitchen? The GACC?s ?stove
catalogue? rates performance based on the WBT which contains so many
conceptual and calculation errors that it renders all test results
irrelevant! How may times must that conversation be held? Simply correcting
the major calculation errors in the WBT moves the stoves around the chart
dramatically. If Berkeley can?t do math and the GACC won?t fix it, we
should simply move on to some rating method that reflects reality. The
entire stove community cannot continue to be held hostage to incompetence
that happens to serve select groups.

The statement that people use solid fuels because of a lack of access to
?clean fuels? assumes that solid fuels are ?unclean?, haram, unwanted,
untouchable: Dalit fuels. There are numerous cases where liquid and gaseous
fuels are available and shunned in favour of solid fuels. The reason is
often economic, but that does not mean ?poverty?. Just economy.

LPG is not acceptable to some people, even whole regions. It is
logistically unacceptable in many regions, and we do not exist to give
subsidies to Big Gas. Biogas, wood gas and coal gas are perfectly viable
alternatives to LPG which is expensive. The industry that supplies it is
highly tied up with a very small number of distributors. It would cut
millions of jobs out of energy industries were it to become ?required?.

?Making the available clean? is obviously the sensible path to take. The
paragraph proposes, in toto, that solid fuels cannot be burned cleanly, and
further, that liquid and gas fuels can, and are, and are safe doing so
(this is all about protecting the public, right?). Note the confabulation
of indoor air quality and unvented stoves with chimney stoves and outdoor
air. This technique, or trick if you must, tries to give the reader the
idea that because a stove that emits all its smoke indoors, it cannot be
made clean enough with a chimney to produce an outdoor PM2.5 level that is
acceptable. Key to this untruth is the claim that stoves with chimney
cannot be clean burning (no technological improvement is possible) and that
they leak so much smoke from the stove that the IAQ problem will persist at
least in a modeled fraction of kitchens that is above some arbitrary level.

If you did not follow this last point, have a look at how the WHO?s
exposure model works. The estimate that there are really good and bad
kitchens and stoves and the model is set up to always estimate that some
combination of bad kitchens and stoves exist, therefore there will always
be ?failing? combinations. These may not exist at all, but they exist in
the Monte Carlo Simulations so by gum they probably exist in real life.

To always have some kitchen-stove combinations fail, they heroically assume
that an average 25% of the emissions leak from chimney stoves, and that
there are no clean burning fires in all stoves fitted with chimneys.
Because it is so obvious that a reasonably clean burning stove with a
reasonable chimney such as is found throughout Asia would leak basically
zero smoke into the room (while burning a solid fuel) some excuse has to be
invented not to do the obvious. I say obvious because millions, or billions
of people across Asia and North America already figured this out and put
chimneys on their heating and cooking stoves. This invention apparently
didn?t reach California.

?These new improved biomass stoves vary enormously, but none have yet been
shown to sufficiently reduce exposure to PM2.5 to comply with the WHO's
Guidelines for Indoor Air Quality (Smith and Sagar, 2014).?

Finally some relief, thanks to Fresh Air (Netherlands), Dr Talant
Sooronbaev and the World Bank?s Kyrgyzstan heating stove pilot programme.
Together they definitively showed that solid fuel stoves can be locally
made and installed by local contractors and supplied with local fuels and
operated by local people and that the exposure to PM2.5 can be reduced from
a 24 hr level of 200-800 ?g/m3 to 10-40. (There is a range because even
walking through the house with boots on can raise the level to 100 for a
few minutes. A lot of cooking creates an exposure well over 40 so we have
to be at least a little realistic about what constitutes a ?health
protective? level.)

Good, then. It is settled. The claim that solid fuels are not being able to
be burned cleanly enough to protect health is definitely disproven.

The starting and finishing positions of this paper needs to be corrected in
light of the clear evidence contradicting them.

Regards
Crispin
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