> Finally, returning to the questions posed at the start, we conclude that although there is a large and growing body of evidence linking exposure to wood/biomass smoke itself with both acute and chronic illness, there is insufficient evidence at present to support regulating it separately from its individual components, especially fine particulate matter. In addition, there is insufficient evidence at present to conclude that woodsmoke particles are significantly less or more damaging to health than general ambient fine particles.
> Nevertheless, given the importance of woodsmoke as a contributor to particle concentrations in many locations, strategies to reduce woodsmoke emissions may be an effective means of lowering particle exposures. In addition, given the weight of toxicologic evidence, additional epidemiologic studies are needed to confirm our conclusions.
As much as I complain that sloppy research oversells its conclusions, I tend to forget how often reporters will take a good paper and simply skip all the lines like "not significant" and "no causation" that stand in the way of an exciting article.
Everyone is rallying around autonomous cars to decrease unnecessary deaths (and rightfully so), but relatively few folks are familiar with rocket stove technology.
https://richsoil.com/rocket-stove-mass-heater.jsp
https://en.wikipedia.org/wiki/Rocket_stove
Releasing smoke is energy inefficient, since it's literally unburnt fuel! Considering the fuel savings, the lifetime cost of switching can be negative in some cases.
In terms of cost per statistical life saved, it's an extremely compelling technology.
This is a problem with normal wood-burning cooking stoves as well. Smoke doesn't go into the chimney until you establish a convection draft or the wind creates a venturi effect.
Smoke free startup is an important design/operational consideration. There are lots of videos demonstrating startup technique (search "rocket stove starting"). Here's a couple good ones: https://www.youtube.com/watch?v=Ls_eqNB6d0Y&t=1m23s https://www.youtube.com/watch?v=aSkUquOQt5w
Note that the goal of the drafting chimney is not to soak up a lot of heat, but rather to be insulated and have low thermal mass to minimize heat loss. The higher the air exit temperature from the riser, the stronger the draft. The important thing for self-drafting is to heat the air in the riser, and only secondarily heat the riser material itself.
A good design should make startup as "idiot proof" as possible. I've seen a few builds that use a 12V case fan on the air intake. Since the goal is to heat up the air in the riser (and that heating the riser... draws hot air into the riser), all you have to do is "tip it over" into that stable equilibrium.
Imo there's a market opportunity for an inexpensive, compact, nice looking, and easy to operate rocket stove. The open source (and excellently documented) "batch rocket" design seems a good place to start. http://batchrocket.eu/en/
To that list of rocket stove applications & advantages would add backup heat for solar hot water, accessible to developing countries and the poor, and (when built from masonry) ease of construction in the charred afterscape. I'm kidding of course on that last one. Mostly. ;)
But if your options are, stay close to the fire or die, that's an important selective pressure
And yet very few sane people wish to ban wood smoke. It smells good. There's nothing like the smell of fall and winter, with fragrant smoke blanketing the countryside.
I'm perfectly aware that wood smoke is bad for me, that it pollutes my lungs and makes my food poisonous. But it's delicious.
On the other hand, if the neighbors are burning wet wood, pine or otherwise Doing It Wrong maybe they would appreciate a friendly heads up.
It's essentially just a big hole with an air intake tunnel, so that fires in the pit combust more completely, with a very significant reduction in smoke and particulates.
You probably can't do anything about them being ideologically inconsistent with respect to burned fuels as an energy source, but you can reduce their impact on yourself and your mutual neighbors.
From the article up there I get the sense that wood fires inflict a lot of particulates even when you can't smell smoke, but open-air fires are still way safer (on this level) than in-home ones.
>There is no amount of wood smoke that is good to breathe. It is at least as bad for you as cigarette smoke, and probably much worse. (One study found it to be 30 times more potent a carcinogen.) The smoke from an ordinary wood fire contains hundreds of compounds known to be carcinogenic, mutagenic, teratogenic, and irritating to the respiratory system. Most of the particles generated by burning wood are smaller than one micron—a size believed to be most damaging to our lungs. In fact, these particles are so fine that they can evade our mucociliary defenses and travel directly into the bloodstream, posing a risk to the heart. Particles this size also resist gravitational settling, remaining airborne for weeks at a time.
>Once they have exited your chimney, the toxic gases (e.g. benzene) and particles that make up smoke freely pass back into your home and into the homes of others. (Research shows that nearly 70 percent of chimney smoke reenters nearby buildings.) Children who live in homes with active fireplaces or woodstoves, or in areas where wood burning is common, suffer a higher incidence of asthma, cough, bronchitis, nocturnal awakening, and compromised lung function. Among adults, wood burning is associated with more-frequent emergency room visits and hospital admissions for respiratory illness, along with increased mortality from heart attacks. The inhalation of wood smoke, even at relatively low levels, alters pulmonary immune function, leading to a greater susceptibility to colds, flus, and other respiratory infections. All these effects are borne disproportionately by children and the elderly.
>In the developing world, the burning of solid fuel in the home is a genuine scourge, second only to poor sanitation as an environmental health risk. In 2000, the World Health Organization estimated that it caused nearly 2 million premature deaths each year—considerably more than were caused by traffic accidents.