Read on ONLY if interested in potential harm from sawdust.
Excerpt from a British Medical Journal Article:
"It should be noted that in some of the large scale general population studies assessed by the American Thoracic Society, the original aim was to determine the overall impact of workplace exposures on the population burden of COPD, and not necessarily to identify workplace specific causes. However, in certain studies, information was sought on the specific substances and occupations associated with increased prevalences of COPD. Occupations linked to increased prevalences of COPD include construction, leather, rubber, plastics manufacturing, plastics and rubber workers, textiles, food products, spray painters, and welders. Specific substances linked to higher prevalences of COPD include quartz, welding fumes, wood dust, sawdust, asbestos, and solvents."
The full article can be found at: http://oem.bmj.com/content/62/4/212.full
And a couple of other articles: http://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/
http://billpentz.com/woodworking/cyclone/index.cfm