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Wood / Dust Toxicity

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Wood/Dust Toxicity
Edited by: Bruce Campbell

For centuries, it's been fairly common knowledge that some woods could hinder your health. As far back as 60 A.D., the Roman historian and naturalist Pliny the Elder described a case where four soldiers actually died after drinking wine from hip flasks made of yew. Of lesser gravity was the experience of a few German sawyers in the early 1700s. It seems they developed chronic irritation of the nose and eyes, as well as headaches, from sawing bald cypress.
What are your chances of a reaction to wood? Statistics say that only 2 to 5% of all people develop an allergic sensitivity to one or more compounds found in wood. But, if you handle a lot of potentially toxic species, and work with them long enough,you increase your chances of an allergic reaction. And, with sufficient exposure, some woods bother almost everyone.
Any dust, including wood dust, mildly irritates the sensitive mucous membranes of your nose and eyes, making you sneeze and tear. The dust of some woods such as western red cedar and rosewood can be especially bothersome. However, other woods, called irritants, can make you even more uncomfortable, with a rash that classifies as either irritant dermatitis or allergic dermatitis. The rash usually has a uniformly red, swollen area that may erupt in blisters, and typically first shows up on the webs of skin between your fingers. Irritant woods include black locust, cocobolo, ebony, oleander, satinwood, sequoia, and yew.
However, for you to get an allergic-type rash, you first must be allergy-prone to one of more of the chemicals found in certain woods called sensitizers. And, it may take repeated contact for your body to develop a great enough allergy for it to react (the so-called "latency period of as little as five days and up to 6-8months). If you do eventually get a reaction, the rash will look like poison ivy - red with small, individual, itchy bumps. Sensitzer woods include cypress, balsam fir, beech, birch, elm, greenheart, mahogany, maple, myrtle, redwood, sassafras, spruce, walnut, willow, western red cedar, and teak.
In addition to the actual wood dust, molds frequently trigger reactions, too. One that actually grows in wood happens to be extremely potent: Cryptostroma corticale. This mold lives happily between the bark and sapwood of many hardwood trees, especially favoring maple and birch. It's responsible for the marbleized spalting that woodturners prize, and for "maple bark stripper's disease," a condition with all the symptoms of a severe respiratory allergy.
If you have an aspirin allergy, be wary of willow and birch. Both of these species possess significant concentrations of salicylic acid (the predecessor of aspirin) and very sensitive individuals might only need casual exposure, such as a whiff of sawdust, to react.
Never say "no" to a dust mask. Among woodworkers, the chances of developing nasal and sinus cancer run about 5-40 times greater than non-woodworkers. Although researchers haven't identified the exact cancer-causing compound (primarily because the disease has a latency period from 30 to 50 years), some evidence points to dust from wood with high tannin content, such as chestnut, oak, redwood, western red cedar, and hemlock.
If you are sensitive to wood dust, work in a well ventilated area (this also reduces the risk to mold), avoid unseasoned wood as much as possible, and wash or shower frequently. If you develop persistent rashes or respiratory problems, contact your physician or dermatologist. (source of above: http://www.city-net.com/albertfp/toxic.htm)
There is an interesting list of Internet sites at http://www.davidillig.com/awg/safety.html where you can find additional information.
The chart below is a blend of information from two sources. The first is an article which appeared in American Woodturner in June 1990 (originally posted to rec.woodworking by Bruce Taylor (I took it from the Ohio Valley Woodturners Guild http://w3.one.net/~ovwg/Tips-Toxicty.html). The second is an article prepared by Roy Banner, a woodturner from Torrance, California who almost lost his life in 1989 to anaphylactic shock after turning pieces of exotic wood (see http://www.mimf.com/archives/toxic.htm ). Roy has assembled his data over the years from various sources. I can't judge with any authority the validity of the information and it's up to the you to further research any wood yourself. Take this as a jumping off point. You might also want to check out The Botanical Dermatology Database at http://bodd.cf.ac.uk/BoDDHomePage.html although I found it pretty hard to follow, technically.
A final note; this data does not take into consideration the added effect of formaldehyde in plywood, treated woods, sodium compounds in white pine to prevent blue stain, etc. Also, I am not aware of any work to study the interactions of woods and chemicals such as oils, glues, stains, etc. Bottom line - ensure good ventilation and good respiratory protection when you work in the shop.
Wood Toxicity Chart
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Index of Meanings
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[1] Cancer of nose and sinus: Statistics show that woodworkers have a 40 per cent greater chance of nasal cancer than the general population. However, the majority of statistics on nasal cancer are based on data from 1920-1960 when the furniture industry became highly mechanized with little or no dust control methods.
[2] Irritant or Sensitizer: Woods are either an irritant which cause a reaction fairly rapidly after exposure and will cause a similar reaction repeatedly, or sensitizers which may have a latency period of hours or months and may require repeated handling before reaction occurs. Sensitizer's are the more severe, because once you're sensitized, you're sensitized for life and the reactions only get more dramatic.
[3] Potency: This is the potential of the wood or sawdust doing harm and would vary with the individual. i.e., those who are allergy prone might think twice about working with wood classed as extremely potent.
[4] Risk: This is a qualitative assessment of the risk of a given wood doing serious harm. It is derived by combining the Potency and Incidence measures as follows:

chartindex2.gif

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View Postgeez look what I brought onredface.gif

 

 

This is information cwm15.gif that all plug builders / wood turners should be aware of.

 

The life you save may be your own! angel.gif

 

Bernzybucktooth.gif

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Thats just Toxicity,,, I see no mention of silica..Took a 30 hr. osha course, they said silica is the next abestos.. Same barbed type particle .. Goes in lungs never comes out . We were talking about hammer drilling concrete or grinding concrete . Then the subject turned to hard woods . Pretty much the harder the wood the more silica . enjoy .... AYC gives me a headache and I'm not the only one .. cwm31.gif .. I never have headaches.. never... AYC = headache.. cwm31.gif

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Here's More">The primary irritant in cedar is plicatic acid and western red cedar contains the highest concentrations although eastern white cedar (Thuja occidentalis) and Japanese cedar (Cryptomeria japonica) also contain it. Exposure to plicatic acid can cause or exacerbate asthma, rhinitis or conjunctivitis in humans and in animals, and the damage can be progressive. Asthmatics who are continuously exposed to cedar, such as in a lumber mill, experience deterioration in their asthma over time. In pine (family Pinaceae), the primary irritant identified is abietic acid, sometimes called sylvic acid. Pine products also include pine resin, also known as rosin or colophony, which is known to pool players and mountain climbers. Pine resin is also used in adhesives, paints and varnishes, inks and in sizing for paper, paperboard and fabrics (Sadhra 1994). Abietic acid itself elicits relatively weak allergic responses, however, a number of compounds formed by air oxidation of abietic acid are potent contact allergens (Hausen 1989, Karlberg 1988).

Plicatic acid has been shown to cause an array of pathological changes consistent with inflammatory and allergic reactions. However, no one knows the mechanism by which plicatic acid induces these changes, which include increased concentrations of eosinophils, immunoglobulin E (IgE), T-cells, histamine and leukotrienes--substances known to increase inflammation in conditions such as multiple organ failure following surgery and acute respiratory distress syndrome (Frew 1995, Chan-Yeung 1994, Salari 1994). The overall increase in IgE concentrations found in humans with red- cedar asthma (Frew 1995, Paggiaro 1987) indicates an overall sensitization of the immune system to a foreign substance. Similar increases in IgE levels also accompany allergic reactions and parasitic infections. Allergists and immunologists refer to this immediate immune response as a type-I hypersensitivity reaction. Humans can also exhibit a delayed reaction to red cedar or plicatic acid exposure--also known as a type-IV hypersensitivity reaction, which is the type of response seen in tuberculin skin tests in humans. Following exposure to red cedar or plicatic acid, a person with occupational asthma may have either an immediate, or a delayed reaction, or both (Malo 1989). Long-term exposure to red cedar or pine in humans can lead to a decrease in forced expiratory volume, or FEV, a measure of lung capacity and ability to breathe freely (Shamssain 1992, Cote 1990, Malo 1989). Plicatic and abietic acids can both cause destruction and desquamation, or sloughing, of alveolar, tracheal and bronchial epithelial cells (Ayars 1989).

Among the known causes of occupational asthma, red cedar has a significant impact compared with most other occupational exposures. One study compared four groups of employees who worked at jobs that exposed them to respiratory irritants: cedar sawmill, paper pulpmill, grain elevator and aluminum smelter workers. The sawmill workers had the highest overall prevalence of asthma compared with a control group of persons without any occupational respiratory exposure (Siracusa 1995). Studies of workers exposed to pine dust also show that such work is associated with significantly more respiratory symptoms and a greater risk of airflow obstruction (Shamssain 1992), and the results of a German study indicate that workers exposed to pine dust had more than a three-fold increased risk of glottal cancer (relative risk = 3.18, 95% confidence interval: 1.1-9.0) (Maier 1992).

In humans, occupational exposure to cedar leads to asthma in 50% of more of wood, paper and pulp mill workers (Malo 1994, Rosenberg 1989). One might expect that longer exposure to cedar or pine dust would result in worse or more persistent respiratory symptoms, but that is not clear from various studies. Some researchers report just that among timber workers with occupational asthma who remain exposed to wood dust (Rosenberg 1989). In contrast, a large study of British Columbia cedar sawmill workers found that physician diagnoses of asthma or respiratory symptoms were not associated with work duration or the amount of dust to which the workers were exposed (Vedal 1986, vol. 41).

Can asthma caused by exposure to wood products be reversed? In the studies of occupational asthma among sawmill workers, the condition vanishes in 50% or fewer cases when exposure stops. The remaining individuals experience intermittent attacks or continued chronic airway restriction that can persist for years or indefinitely (Choubrac 1991, Rosenberg 1989, Newman-Taylor, 1988). In the British Columbia sawmill workers, researchers reported the health status of 17 patients with occupational asthma due to red cedar who had been removed from exposure for at least one year. Seven patients became asymptomatic but 10 (59%) required continued treatment for asthma (Chan-Yeung 1988). In another group of 136 sawmill workers with cedar-induced asthma who had left the industry, only 55 (40%) recovered completely and 81 (60%) had continued asthma attacks of varying severity (Chan-Yeung 1987). In one experimental study, bronchial hypersensitivity lasting two weeks was observed after an individual with red-cedar asthma received a single exposure to plicatic acid (Cartier 1986, vol. 78). What happens to asthmatics if they continue to be exposed? Another study of the British Columbian sawmill workers followed 48 of the workers with asthma who remained on the job. Although 10% of the patients improved, none of them recovered, 62% remained stable and 38% got worse (Cote 1990). Thus, it seems imperative that an individual with cedar- or pine-induce asthma be removed from exposure for any possibility of recovery, and that the recovery occurs among humans only in half of all cases at best.

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Holy crap now you guys are making me paranoid. I've had a headache for the past 2 days and I just recently started turning. And come to think of it i took my respirator off and stayed in the garage for a 10-20 min. looking a few things over.

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The point of this thread is to SCARE YOU cwm31.gifcwm31.gif...................

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into wearing your respirator!!!!

 

And as Tagger mentioned, dust is only part of the danger. The $hit that goes in, but can't come out should scare you as well.

 

If it's not clean air, you shouldn't be breathing itcwm40.gif

 

Bernzybucktooth.gif

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Great info John, I haven't seen that list in a while and it's alwayse a good reminder. What about Pine and Eucolyptus woods?? didn't make the list frown.gif

 

Armand

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