Found this interesting discussion about wood dust on Matthias Wandel's Woodworking for Engineers website.
Measuring dust with a Dylos air quality monitor
To whet your appetite, here are a few excerpts:
"For his dust collector, which is a ClearVue cyclone with six year old Wynn cartridge filters on the output. The baseline reading in the undisturbed shop is around 93 and 33 (< 2.5 micron and > 2.5 micron). With the Dylos right by the filter, the readings went up to 300 and 40 when the dust collector was turned on, then settled back down to around 250 and 5. Then using the chopsaw (connected to the dust collector) to make about ten cuts in hardwood, the readings went to 401 and 39. Two minutes later, the readings went back down to 327 and 37."
"I'm pretty sure that cyclones alone are ineffective at separating the fine dust. The spinning air inside a cyclone is subject to on the order of 100g of acceleration, but the air only stays in the cyclone for about one second. Assuming particle separation rate is proportional to acceleration or gravity, that would suggest that any dust that can stay suspended in the air for over a minute will also make it through the cyclone.
In fact, I'm getting less enamored with the idea of a cyclone. The coarse dust that a cyclone separates out will also relatively easily fall out of a filter bag. Those low-tech dust collectors with a filter bag on top and a collector bag on the bottom look better all the time."
"All this paranoia is from reading Bill Pentz's pages. One thing that Bill Pentz does not mention directly on his website is that he has wood dust allergies. Having wood dust allergies certainly changes the situation a lot, but most of us don't have wood dust allergies."
"On this subject, I exchanged some emails with Dwight A Kaufman, a doctor who emailed me with his comments. Here are some of his emails below. Food for thought!
Subject: Wood Dust
'Hi, Several years ago I attended an Occupational Medicine Continuing Education Conference at the University of Cincinnati. The main subject was Occupational Lung Disease. I asked one of the lung specialist if wood dust cause lung disease. He answered "No" with no hesitation or reservation. Some people do develop an allergy to wood which may aggravate their asthma or hay fever.'
Dwight A. Kauffman MD
In a later email he writes:
'Yes, you may quote me. I do not have a reference. And I’ll offer the following discourse for those interested:
Our airway, windpipe and bronchi, divide 17 or 18 times before reaching the terminal air pockets where oxygen oxygen and carbon dioxide exchange takes place. In about the first half of these bronchi, there is a constant production of mucus that is continually moving up to remove dust, bacteria, etc.
Most wood dust is trapped in this mucus and removed. Tobacco smoke goes all the way out to the air pockets and some comes back out. Some gets trapped.
Asbestos and silica are inorganic material that can be small enough to get in where the removal system doesn’t work. And being inorganic, the body cannot break them down.
The risk of lung disease from asbestos is greatly exaggerated. For 15 years I worked in a community that had had a factory that made asbestos brake and clutch linings. During those 15 years I did not see or know of anyone with the kind of lung cancer asbestos is supposed to cause.
I did my Internship in western Pennsylvania and saw lots of people with Black Lung disease.
Tobacco smoke damages the airways, thus chronic bronchitis. It also damages the air pockets, thus emphysema. These usually occur together and that is known as COPD.
In chronic bronchitis, the wall of the bronchi are damaged, so that when a person coughs or breaths hard, the airway collapses and traps air. In emphysema, the air exchange pockets that are normally like a bunch of grapes break down and look like an apple, loosing lots of surface area for oxygen exchange with the blood.
COPD is almost totally due to tobacco. Asthma is due to inflammation and causes swelling, increased mucus production and spasm, but does not cause the structural damage that tobacco smoke does.
When a company that makes air filters puts a picture of a chest X-ray in their ad, that is scare tactics.
Air filtration is primarily for comfort and esthetics, not health.
Ninety percent of chronic lung disease and cancer are preventable since they are caused by tobacco.
Asthma and allergies are treatable, and should be treated vigorously.
Dwight A. Kauffman MD'"
Measuring dust with a Dylos air quality monitor
To whet your appetite, here are a few excerpts:
"For his dust collector, which is a ClearVue cyclone with six year old Wynn cartridge filters on the output. The baseline reading in the undisturbed shop is around 93 and 33 (< 2.5 micron and > 2.5 micron). With the Dylos right by the filter, the readings went up to 300 and 40 when the dust collector was turned on, then settled back down to around 250 and 5. Then using the chopsaw (connected to the dust collector) to make about ten cuts in hardwood, the readings went to 401 and 39. Two minutes later, the readings went back down to 327 and 37."
"I'm pretty sure that cyclones alone are ineffective at separating the fine dust. The spinning air inside a cyclone is subject to on the order of 100g of acceleration, but the air only stays in the cyclone for about one second. Assuming particle separation rate is proportional to acceleration or gravity, that would suggest that any dust that can stay suspended in the air for over a minute will also make it through the cyclone.
In fact, I'm getting less enamored with the idea of a cyclone. The coarse dust that a cyclone separates out will also relatively easily fall out of a filter bag. Those low-tech dust collectors with a filter bag on top and a collector bag on the bottom look better all the time."
"All this paranoia is from reading Bill Pentz's pages. One thing that Bill Pentz does not mention directly on his website is that he has wood dust allergies. Having wood dust allergies certainly changes the situation a lot, but most of us don't have wood dust allergies."
"On this subject, I exchanged some emails with Dwight A Kaufman, a doctor who emailed me with his comments. Here are some of his emails below. Food for thought!
Subject: Wood Dust
'Hi, Several years ago I attended an Occupational Medicine Continuing Education Conference at the University of Cincinnati. The main subject was Occupational Lung Disease. I asked one of the lung specialist if wood dust cause lung disease. He answered "No" with no hesitation or reservation. Some people do develop an allergy to wood which may aggravate their asthma or hay fever.'
Dwight A. Kauffman MD
In a later email he writes:
'Yes, you may quote me. I do not have a reference. And I’ll offer the following discourse for those interested:
Our airway, windpipe and bronchi, divide 17 or 18 times before reaching the terminal air pockets where oxygen oxygen and carbon dioxide exchange takes place. In about the first half of these bronchi, there is a constant production of mucus that is continually moving up to remove dust, bacteria, etc.
Most wood dust is trapped in this mucus and removed. Tobacco smoke goes all the way out to the air pockets and some comes back out. Some gets trapped.
Asbestos and silica are inorganic material that can be small enough to get in where the removal system doesn’t work. And being inorganic, the body cannot break them down.
The risk of lung disease from asbestos is greatly exaggerated. For 15 years I worked in a community that had had a factory that made asbestos brake and clutch linings. During those 15 years I did not see or know of anyone with the kind of lung cancer asbestos is supposed to cause.
I did my Internship in western Pennsylvania and saw lots of people with Black Lung disease.
Tobacco smoke damages the airways, thus chronic bronchitis. It also damages the air pockets, thus emphysema. These usually occur together and that is known as COPD.
In chronic bronchitis, the wall of the bronchi are damaged, so that when a person coughs or breaths hard, the airway collapses and traps air. In emphysema, the air exchange pockets that are normally like a bunch of grapes break down and look like an apple, loosing lots of surface area for oxygen exchange with the blood.
COPD is almost totally due to tobacco. Asthma is due to inflammation and causes swelling, increased mucus production and spasm, but does not cause the structural damage that tobacco smoke does.
When a company that makes air filters puts a picture of a chest X-ray in their ad, that is scare tactics.
Air filtration is primarily for comfort and esthetics, not health.
Ninety percent of chronic lung disease and cancer are preventable since they are caused by tobacco.
Asthma and allergies are treatable, and should be treated vigorously.
Dwight A. Kauffman MD'"
