Originally posted by BlowinSmoke
How is burning wood...affecting the air we breath? The last time i checked, smoke rises. And, don't trees breath bad air and and produce good air?
The logic of wood burning being unhealthy, just doesn't make sense. Kinda like saying second hand smoke causes lung cancer. Who's writing these
scripts? I SERIOUSLY doubt...smoking cigarettes causes lung cancer. My mom was a chain smoker...practically all her life...and she never got lung
cancer. She did, however, get breast cancer...but it had NOTHING to do with cigarettes! It was more of a result from a poor lifestyle and
unforgiveness in her heart. Some things...she just couldn't let go of. Those things...eventually eat you til you die!
Smoke may rise, sometimes. It varies. Gaseous convection in air is dependant on the density of the gas in question. Basically, if the mass of a in
volume x is less than the mass of b in volume x, a will rise in a medium of b, and vice versa.
The problem with smoke is that it is not solely a gas, it contains carbon dioxide and monoxide (in varying proportions depending on the quality of
combustion) and various solid particulates such as soot and dust.
Carbon dioxide is actually denser than air under standard conditions, but due to the equation pv=nrt, when the temperature is increased (burning) the
CO2 increases its volume (expands) which makes it less dense, so it rises initially.
When the smoke mixture is cooled by the air, the separate components begin to fall back towards the ground level. CO2 is the densest gas found in
smoke, so it falls first. It falls to an extremely low altitude i.e. not even up to your waist and isn't really a significant health risk except in
very concentrated doses.
Carbon monoxide (CO) is a deadly gas in any dose, it is less dense than CO2 and therefore more likely to be inhaled by a human. The problem with CO
is nothing to do with cancer at all. CO is an oxygen (O2) replacement molecule. What this means is that the haemoglobin (Hb) in your red blood cells
has a greater affinity for CO than O2. When a CO molecule attaches to a Hb molecule in your blood, it takes up space usually reserved for O2. The
consequences of this are dire. The presence of CO in your blood reduces O2 partial pressure throughout your body and results in less O2 being
distributed to your cells. When an O2 molecule attaches to Hb, it is released at various points throughout your body by brownian diffusion through
capillary walls. The Hb is then deoxygenated and sent back to the lungs to pick up more O2. When a CO molecule attaches to Hb, it does not diffuse
through any capillary walls and instead stays attached to the Hb until that red blood cell is destroyed and recycled by your body. This can take
This is why smokers experience "lack of breath" - they have to breathe more air to provide the same level of O2 to their cells as if they didn't
CO is produced when carbon is incompletely burned. The (basic) usual reaction for burning wood is:
C + O2 --> CO2
In amateur or poorly designed fire pits, the above reaction is accompanied by:
C + 1/2O2 --> CO
The CO producing reaction will always be present, it is not possible to completely combust anything in reality, but poor air flow and various weather
factors can increase the ratio of CO production to CO2 production.
As for your question about trees breathing bad air and producing good air - no. Trees and other photosynthesising plants do use CO2 in photosynthesis
to produce sugar and oxygen, but that is a completely different process to breathing (respiration) which trees do actually do, in exactly the same way
The problem with that is again, CO2 isn't a terribly bad thing for human health, in high doses it can kill us, yes, but it's not really a practical
health risk. As I explained earlier, the problem with smoke is the CO.
Cancer is not caused by CO2 or CO as they are not mutagens. Carcinogenic particulates in smoke are the cause of extra/additional mutations during DNA
replication which CAN increase your risk of POTENTIALLY destroying your body's multitude of cancer-answer systems. For information on DNA replication
and the process of mutation, see my post on an unrelated topic in which I describe the process here:
reply to post by Dispo
Edit: the process of mutation may not even affect us at all, sometimes it may be like swapping the word rain for reign, other times it may be adding a
d to the word andd, and other times it may be like taking a letter away from the word becuse. The word and sentence would still be perfectly
Sometimes though, it can completely change the meaning of the sentence, like it it removes the n't from the sentence "do put your hand in the
Then bad things happen, tumour suppressing genes don't do what they're supposed to, proto oncogenes become oncogenes and we all die.
N.B. These mutations happen over time, which is why cancer is more common in old people, and why cancer was relatively unheard of back when the
average life expectancy was 40. Cancer is like life's catch-all killer - if the liver and the heart don't get you, cancer comes along and says "that's
your lot." Carcinogens like some chemicals in smoke can accelerate the rate of mutation, which increases the likelihood of bad mutations happening.
That said, I'd rather live to 60 and have fun than live to 90 on salads and jogging.
Finally: lol why would anyone ban wood fires? That's just silly.
edit on 2-1-2013 by Dispo because: (no reason given)