Wood stove pollution and health effects
The weather is getting
chilly...and controversies over wood stoves are popping up all
over. One came into my inbox and another into my blog feed
last week, so I thought I'd weigh in.
First, from our
regular reader Roland:
woodstove. Mostly as a backup and because of the cozy factor. But after reading the [The Fireplace Delusion and Woodsmoke Health Effects: A Review], I changed my mind."
For those of you,
like me, who hate following links, here's the upshot, excerpted
from the first link:
Meanwhile, various
blogs in the homesteading world are posting rants against the
EPA's new policy that would make it illegal to sell your old wood
stove if it emits more than 7.5 grams per hour (g/hr) of
particulates. Here's a sampling of the headlines to give you
a feel for the tone of the pieces:
"Off Grid Attack: EPA To Outlaw Many Wood Burning Stoves"
To help explain my take
on the matter, let's go back in time. Mark and I started out
with a monstrous
wood stove that spewed forth smoke (see the top photo), and
we saved up until we could afford a fuel-efficient
wood stove.
Our current model burns so clean that I can't actually see smoke
once the initial water vapor is driven off. I had initially
reported our Jotul's emissions rate as 5.2 g/hr, but the EPA
website seems
to list it even lower, at 3.4 g/hr.
Am I glad we saved up for the fuel-efficient wood stove?
Very much so! Would I have skipped the intermediate,
polluting step and gone right to the efficient stove? Well,
we couldn't have afforded the efficient stove when we got the
inefficient stove, so knowing what we knew then (not much), we
probably would have just bought an inefficient, used wood stove
locally. It's not as if the EPA is going to send out officers to
look for illegal wood stoves --- their regulations are only going
to be enforced by insurance companies --- so poorer people will
likely keep buying whatever they want used if they can't afford
insurance. I've heard from various people locally that you
can't really insure a home heated solely by wood anyway (at least
around here) unless you install a heat pump and say that's your
primary heat source, so this might not make a big difference.
How do we feel about
the polluting effect of our current wood stove? Pretty
good. I don't have data to back this up, but I estimate the
minimal amount of particulates emitted by our wood stove is so
well dispersed before the smoke hits our nearest neighbor (roughly
a half mile away) that the effects are negligible there.
Here at the source, I figure we're still breathing cleaner air
than the average urban or suburban American, and we have the
benefit of being able to harvest our own fuel sustainably at a low
cost, enjoying radiant heat and wood chopping, and not worrying
about lack of heat during our sometimes-extended power outages.
In the end, I think the EPA rule is a good thing. The first
place I part company with libertarians is the environment --- even
though our government does a poor job of protecting our earth, I
think we'd do an even worst job without its oversight. Since
the current rule will likely push at least some people who can
afford it to change over to a more efficient stove, while not
unduly harming people who can't afford to make the switch, it
seems like a win-win. I'm sure many of our readers will feel
very differently about the topic, though, so feel free to comment.
Or explore more posts by date or by subject.
About us: Anna Hess and Mark Hamilton spent over a decade living self-sufficiently in the mountains of Virginia before moving north to start over from scratch in the foothills of Ohio. They've experimented with permaculture, no-till gardening, trailersteading, home-based microbusinesses and much more, writing about their adventures in both blogs and books.
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If the EPA could back up their regulations with sound scientific studies, I might be inclined to support them, but they can't. They just pick numbers out of their as- um.. the air. The first rule of bureaucracy is to find a non-solvable, probably imaginary, problem to regulate, thus ensuring continued employment for the bureaucrats.
One of the miracles of life is that organisms have the ability to compensate for and survive various insults up to a point. Even coal miners in the old days before respirator masks didn't all get lung disease. How much particulate matter is too much? One heck-of-a-lot. Particulates disperse as they escape a fire by the inverse cube law- 10 feet away they are diluted by 1000th and 100 ft away they're down to a concentration of one millionth.
"Studies" which are usually poorly done and poorly analyzed and pbviously written with preconceived conclusions need to struggle to demonstrate statistical significance of the data. Clinical significance is not impressive. Everything carries risk.
Is a wood burning stove more dangerous than riding in your car? Not even close.
FYI : https://vimeo.com/ondemand/3889 http://en.wikipedia.org/wiki/Rocket_stove http://www.ernieanderica.info/rocketstoves
Here I thought that converting the dead or dying trees on our property into heating our home and then using the ash to fertilize our garden was a wise and earth friendly thing to do. Silly me!!
On the flip side, what is the environmental cost of heating with wood vs using, say, electricity?
Anna, no doubt your stove is quite clean as wood stoves go. But the fact that you don't see any smoke isn't that good of an indicator. The sizes of particles in smoke is generally measured in μm.
Given the visual acuity of the human eye of approximately .3 m / 1000 m, and a near point of the eye at 6 inches for a person in his 40s, that person would be able to see particles of approximatly 50 μm.
Harmful particles are generally divided into "fine" (≤2.5 μm) and "coarse" (2.5 μm - 10 μm). Both are too small to be visible to the naked eye.
And particulates from smoke don't dissipate as fast as e.g. Doc thinks (his numbers are the only true for perfect mixing over the entire volume). Just as an example; up to 30% of the fine particulate matter measured in California comes from China, at least 6500 miles away...
The "environment" is an emotional trap. TPTB are using this platform to control all people in every aspect of life. You need permission to fart, and soon that will be regulated, and taxed.
Anna do me a favor and do some research. The environmentalist is mostly a naive patsy who has no clue he is being used towards a bigger agenda. I.E. Agenda 21 and Sustainable Development!!!!
Smoke has been around for a very long time. The Indians used to burn the Prairie because it was very good to do so. Now.......it's regulated, and you need "permission" to burn your land in early Spring. They actually want to stop the practice. Do you know what happens to a Prairie that is not burned?
Edith
Mike's point is well taken about fires in an urban or suburban setting. But do we need the EPA to dictate common courtesy when dealing with neighbors? I remember living in Chicago when everybody had coal furnaces. The air was thick with soot yet nobody developed lung problems due to it. (Asthmatics are aggravated by air pollution, but asthma is not caused by it.)
Roland's point is also accurate, but particulates from China can only be measured with sensitive techniques. As anyone knows who's ever built a campfire, you don't stand down wind in the smoke.
Anna's homestead is a good distance from her nearest neighbors. The cleanliness of her fire is immaterial to anyone's health or emotional sensitivities. Why should she have to pay more for a govt mandated "clean" stove if it will have no actual impact on anything but her pocketbook?
I think wood burning is a good for me, bad for everyone type of problem - meaning if its just me doing the burning, its fine and no big impact, but if everyone else does it too, the additive affect is unsustainable.
For that matter, homesteading probably fits this bill too, there likely isn't enough arable land on the planet, at least at present technology and population levels, for everyone to feed themselves, and surely not enough trees dispersed within the population for every Tom, Dick and Harry to meet their heating needs with wood. Anyone who has studied the problem of firewood in the real third world knows how unsustainable and degrading to the environment large scale reliance by a modern society on wood really is. So it may boil down to an existential and ethical inquiry that must go beyond a simple assessment of your limited impact as an individual in your immediate environment of using a readily available and "cheap to you" combustible resource.
As a regulator of public utilities, I know for a fact that the large the system of producing power, the more effecient and environmentally sustainable it is. Our "microgrid" village power systems in Bush Alaska are incredibly ineffecient and costly to run, but our modern power systems in Anchorage, Juneau, and Fairbanks deliver power at or more effeciently than many lower 48 systems. So system size is important, and off-grid living is either ineffecient, or as Anna pointed out with the comparative price of her clean stove, costly.
Smoky stoves I live in a fairly dense suburban neighborhood of quarter-acre lots. I made a conscious decision to buy a modern airtight stove to save my neighbors the inconvenience of seeing and smelling my stove. As with Anna's stove, there are no visible emissions once the fire is established. Some other neighbors burn old stoves that result in a constant smoky haze...it's a real problem. Although I enjoy burning wood, I can see why governments in more densely populated areas might mandate more efficient stoves. Much like people running junker cars, I don't want to breathe degraded air because someone won't spring for a new model. Comment by Mike Gaughan — Wed Oct 2 11:39:34 2013
Mike Maybe they can't spring for a new model. Maybe it is the best they can do for the time being. If I get behind a garbage truck, load of hogs or cattle and can't stand the smell I pull over or go around, but I don't want the government to mandate a new law or regulation on behalf of my nose.