by Professor Gene Wengert
Q.
I have seen some comments on rec.woodworking about the dangers of breathing wood dust, but none have been very specific. I posted a specific question, but got no responses except one wise-guy who said, "Breathing wood dust is bad for you." Thanks a lot.
Could you give me some specific information, or point me to a good article? I am a woodturner who turns almost exclusively hardwoods native to Northeast Ohio: maple (several species), walnut, black cherry, pinoak. Some of what I turn is spalted: what are the specific dangers there? Just how careful do I have to be?
A.
Regarding the issue of wood dust, one must realize that it both a political and medical issue. The brief history of wood dust is that in England a rare form of nasal cancer showed up in 2 studies (1965 and 1968) and the common denominator seemed to be furniture and cabinet workers, which was translated to wood dust. But the occurrence of the cancer was extremely small, so the study is somewhat questionable at best. Other European studies failed to show a connection. It is worth noting that England processed a large volume of tropical timbers.
In the late 1970s, the National Cancer Institute did a study and found 37 nasal cancers listed as the cause of death; 8 were furniture workers. In England, a follow-up study failed to find any workers who had nasal cancer, and who worked in a furniture factory after 1945.
What do we know about wood. There are several tropical species that have high silica content. This chemical often results in nasal irritation on many people. There are also many people allergic to dust, molds, and other chemicals in wood.
In the 70s and early 80s, several groups studied the cancer risk from dust. It was weak. Then in 1985, OSHA was prohibited from regulating wood dust under the "nuisance dust" standard. So, OSHA begins the process of regulating wood dust, with a standard in 1989 and a subsequent court ruling making it ineffective, and so it goes today.
The basis for OSHA's initial rules were: 1) the evidence of carcinogenicity of wood is inconclusive; 2) a maximum exposure of 5 milligrams per cubic meter is appropriate for the irritant effects of wood and worker comfort. There was some evidence that softwoods (esp. western red cedar) were worse than hardwoods. Other groups wanted 1 mg/cubic meter.
Hope this helps you decide whether you want to breath wood. I personally use a very good dust filter mask at all times.
Professor Gene Wengert is Extension Specialist in Wood Processing at the Department of Forestry, University of Wisconsin-Madison.
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