For the Experts: Radon & Leaf smoke

Technical questions that one would like posed to experts
(scientists) in fields related to particulate pollution.

For the Experts: Radon & Leaf smoke

Postby edwardgreisch » Tue Oct 17, 2006 10:03 pm

Smoking tobacco causes cancer because the radioactive gas radon seeps out of the ground and sticks to tobacco leaves. This radon gets into the lungs with the tobacco smoke. The radiation from radon causes cancer. [There has always been background radiation. All rocks contain uranium, usually a few parts per million. The radioactive decay of uranium produces radon.]
The question is: Does radon also stick to the leaves of trees? If so, does this radon wind up in the lungs of people when leaves are burned?

Uranium sticking to tobacco leaves and tree leaves

Postby JackPine » Fri Oct 20, 2006 12:02 pm

It is not the radon that causes lung cancer when you smoke tobacco. Radon has a half life of just under 4 days (3.8 days). So by the time the tobacco is harvested and put into the packs of cigs, radon is not the issue. Tobacco causes lung cancer due to all of the other hazardous chemicals in it.

Now to your question about tree leaves. Radon doesn't "stick" to leaves. I have heard of it staying on synthetic fibers (rayon, polyester) due to static charges, but never a natural fabric.

Once again, it wouldn't be the radon burning which caused health problems with burning (smouldering) leaves. The issue there is the incomplete combustion of the volatile compounds in leaves. In fact, any sort of biomass which just smoulders is emitting hazardound, cancer causing pollutants into the air. With leaves there is also the fine particulate matter which can trigger asthma attacks.

The leaves should be composted rather than burned.
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Radon & Woodsmoke

Postby repace » Fri Oct 20, 2006 6:00 pm

Radon is a noble gas and cannot attach to anything. It is long-half-life radon progeny in tobacco that increase the risk of lung cancer along with the other 67 carcinogens in tobacco smoke. JackPine is correct: woodsmoke, like tobacco smoke, coal smoke and other low-temperature combustion will form many products of incomplete combustion that are carcinogenic. Wood smoke pollution is the passive smoking of the outdoors. The most-exposed individuals, like active smokers, are the wood burners and their families. Wood smoke is even more carcinogenic than tobacco smoke. If you have to have a fireplace, a gas-burning fireplace is the best choice. Burning wood to heat your home is 3rd World.
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woodburning and the environment

Postby JackPine » Tue Oct 24, 2006 6:21 am

repace, the burning of wood for heating a home may also be done in the third world, but in areas where there is no natural gas, the overall effect on the environment on a world scale is less than that of oil.

I burn 5 cord of wood in an EPA certified wood stove to heat my house. This is enough to last me all the heating season. The only oil I use is to heat my domestic hot water. The wood I cut comes off my own 30 acre lot which I manage to promote healthy tree growth and a habitat for wildlife (deer, wild turkeys, pheasant, partridge, etc.). It takes maybe 3 gallons of gas to twitch the logs to where I cut it to stove length. The 5 cord I cut takes about 7 gallons of gas in the chainsaw. So, I get the equivalent heat of 600 gallons of fuel oil by burning 10 gallons of gas (a cord of wood is roughly the same as 120 gallons of heating oil when you look at stove and oil burner efficiency).

Now look at how much pollution would have been created to get the 600
gallons of heating oil to my house:
1) The crude had to be shipped to the refinery. If it is from the Middle East that is quite a bit of fuel burned in the ship; if it is from a domestic source that might not be too much.
2) The crude had to be refined. This processing of crude is very polluting.
3) Once the heating oil portion of the crude is refined, it has to be shipped to the oil terminal. That is either by pipeline, rail, truck or more likely a mix of these. Truck or rail requires fuel to be burned and that adds pollution to the air.
4) Now the oil has to be trucked from the terminal to a smaller, local terminal. This is typically in the large tankers. Still more air pollution.
5) Finally, the peddler trucks it to the house. Still more air pollution.

So when you look at the impact my 5 cord has vs. the impact of the 600 gallons of fuel oil I would have used, the 5 cord has much less of an impact on the environment as a whole. If you have to buy your wood and have it trucked, there is some more pollution, but usually that is a local dealer and would still be less than the oil when looked at from ground to stack.

The other benefit of wood is that if the pile tips over, you can stack it back up; when a tank of oil spills, it takes a considerable amount of energy to clean it up (excavate the soil, process it to remove the oil, etc.). That is a good scenario where you can get the soil before the oil travels very far downstream.

If you can get it, natural gas is great, but also must be processed. Propane is clean as well, but it is derived during oil and natural gas processing, so it has pollution associated with the front end as well.

Wind, solar and hydro are clean, but they all have their drawbacks as well. But that is another topic.
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3rd World

Postby repace » Tue Oct 24, 2006 6:36 am

JackPine, I don't disagree with your analysis on a global scale. If we all lived on 30 acre lots there wouldn't be much of an argument. In urban or suburban areas, where people live cheek by jowl, woodsmoke is a major air pollutant. I would also venture to guess that the air inside your home is polluted with woodsmoke due to backdrafting of the stove in high winds.
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indoor air quality

Postby JackPine » Tue Oct 24, 2006 9:37 am

Repace, yes, in urban/suburban areas where the lot sizes are small, just a couple of woodstoves makes quite an impact.

I have a two story house and the chimney is 27+ feet tall. Backdraft through the stove is not an issue on windy days; plenty of draft. I'd dare say the air quality in my house, even with a wood stove, is better than in urban settings due to the minimal automobile/truck exhaust (which are the sources of over 70% of hazardous air pollutants in urban areas). Plus, I only have tile and hardwood floors so there are no toxics off-gassing from the carpets or vinyl flooring.

If oil prices had continued the way they were headed a few months ago, there would have been many, many more wood stoves being used by this time. Thankfully the prices dropped and people don't want to be bothered with messing around with wood, even though heating oil at $2/gallon is still more expensive per BTU than firewood at $175/cord (yes, that is taking the efficiency of both heating sources into account).

The best bet for the reduction of wood smoke is to start with making OWBs meet some standard for emissions, replace old residential woodstoves with EPA certified, and educate people on how to combust wood. One sure way to reduce wood smoke is to make alternative sources of heat such as solar and geothermal more affordable.
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EPA Study shows EPA Certified Stoves program a failure.

Postby pm2.5mary » Tue Oct 24, 2006 10:33 pm


You are so right about making solar and geothermal heat more affordable!
It would not cost money overall but would save billions in pollution related death and disease.

Your estimates of the traffic pollution in urban areas is off however. We have good science on the website about sources of pollution:
When you review the numbers, keep in mind that they are annualized. On many winter days in the SF bay area for instance wood smoke can be 90% of the deadly fine particulate pollution.

Living on 90+ non-wood burning acres I still have invasions of wood smoke in my home and in our office. In this rural oceanside area I live in 'healthy' fear of exposure to smoke as it infects both the little towns and the countryside as well as my property. When you do your calculations of pollution add in the cost of running air cleaners in all the other houses. Long trending illness needs to be factored in for the burner and his neighbors. What is the pollution bill when you are treated for heart disease cancer or infections? All the transportation to doctors and treatments and the manufacture and endpoints of the medications and chemo.

You do sound like someone who is interested in selling more wood stoves!
"best bet (is to) replace old residential wood stoves with EPA certified stoves".
1) There is no "best bet" with EPA Certified Stoves, see the science and do read the entire 67 page report (It is one of 20 such reports we have on file)on the disappointing results of that program. (it is available to you from our website):
This page shows what pollutants the EPA Certified stove user lives in. It is serious health damaging pollution. When they are producing less smoke when they are new the pollution is more carcinogenic. It may seem meaningless to a healthy person, but when (not if) that person slides into the 50% of the population that is vulnerable at any one time, it will make a big difference in disease outcome.

2) What are the number of "old" woodstoves still left? The sales campaign to 'change out to cleaner EPA Certified' has be going on for 20 years. Enough years to go back and do many 7 year studies. Instead of solving the deadly smoke problem it merely lulled the buyers into comfort in their ignorance, as has the second part of your reply about teaching people to burn right. And it sold ever more stoves.
As Dr. Robinson says" Ideally, all prospective purchasers should be informed that authorities such as the Australian Lung Foundation, the American Lung Association and the UK Department of Health and the Environment recommend not using woodheaters when non-polluting alternatives are available.

3)You suggest OWBs be made to meet standards for emmissions.
Solid fuels are many orders of magnitude more polluting than oil and gas and geothemal and solar. 1 OWB can pollute as much as 8,000 homes using natural gas! (or propane). So what kind of standards do you mean?
The heros here are the towns that have the moxie to ban OWBs outright.

We don't need industry leading another EPA certification cycle.
When the EPA proposed the certification of wood stoves back in 1988, they estimated that there would be more cancer deaths, etc., and they were right.
"Particulate pollution is the most important contaminant in our air. ...we know that when particle levels go up, people die. " (Joel Schwartz, Ph.D., Harvard School of Public Health, E Magazine, Sept./Oct. 2002)
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heating homes

Postby JackPine » Wed Oct 25, 2006 6:35 am


I'm not a stove salesman, just a realist. A woodstove changeout to the EPA certified stove is a step in the right direction. The new stove is more efficient in burning the wood, thus, less wood is burned to heat the hosue. Less, wood burned, less pollutants. Plus, although they may not stay at the emission levels as originally certified, they still are better than the old stove. As for the OWBs, europe has models which are far cleaner than those US models which appear just to be slapped together. Ideally, OWBs would have to meet at least what the residential stoves have to meet for emissions. All small steps, but at least they are steps forward.

The bottom line is it doesn't matter how much info you give out, if someone is determined to burn wood you will not be able to convince him/her they should not burn wood. You can try to outlaw wood burning stoves, but when it comes right down to it, laws can be changed back to allowing wood stoves when enough people can't afford oil to heat their homes and the geothermal and solar options are too high as well. Maybe people in CA have more affordable fuels (or make more money) than those in MN, VT, NH, NY, etc.

I still stand by my position that 70% of the hazardous air pollutants emitted originate from mobile sources (I said automobiles/trucks, but this also includes trains, airplanes and marine vessels). PM2.5 is not a HAP as defined by the EPA. I will agree that in certain terrain the fine PM will be extremely high, especially during certain weather events.
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