Wood Dust and Lung Cancer - Who's at Risk?

Occupational Exposure to Wood Dust as a Cause of Lung Cancer

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Is wood dust a risk factor for lung cancer?. Istockphoto.com

Can exposure to wood dust cause lung cancer? What do you need to know if you work near wood dust on the job or through your hobbies? What is a "safe exposure" and what precautions should you take?

Wood Dust and Lung Cancer

Wood dust is one of the oldest occupational exposures known to man, and it's still very important to today for those who have jobs ranging from cabinetry to mill workers.

Considering the number of people involved in jobs where exposure to wood dust could put them at risk of lung cancer, we'll take a look at the evidence to date linking the two.

Yet first, it's important to first talk about the importance of general on-the-job exposures and cancer. It's currently thought that occupational exposures to chemicals and other substances are responsible for up to 27 percent of lung cancers in men. Though this number is frightening, there is much you can do to avoid being a statistic.

Keep in mind that lung cancer is a multifactorial disease. What this means is that most often several risk factors for lung cancer work together to either cause or prevent a cancer from forming. For example, we know that both asbestos exposure and smoking can cause lung cancer, but when the two are added together the result is greater than if you added the two risks together. In contrast, that there are some foods that may lower lung cancer risk and exercise can help as well.

Whether or not you work around wood dust, take a moment to learn about the occupational causes of lung cancer and what every worker should know.

Wood Dust as a Carcinogen

Wood dust is now considered a carcinogen, a substance thought to cause cancer in humans. Wood dust is made up of a conglomeration of different substances derived from hardwood or softwood trees.

Hard Woods vs Soft Woods

Several of the studies on wood dust and lung cancer distinguish between softwood dust and hardwood dust, with hardwood dust being significantly more likely to cause cancer.

But what constitutes hardwood and what are softwoods?

  • Hardwoods are deciduous trees, those that lose their leaves in the fall. Wood from some hardwood trees is actually very soft, such as birch and balsa.
  • Softwoods are coniferous trees; trees that do not lose their leaves but remain green year round (evergreens.)

Wood Dust and Lung Cancer Risk - What do the Studies Tell Us?

Many studies have looked at the relationship between wood dust and cancer. A 2015 review looked at 70 studies to date in the process of asking, "Does wood dust cause cancer?" The strongest link is between nasal adenocarcinoma (a head and neck cancer) and wood dust. Overall, however, it was found that there is moderate evidence that wood dust can lead to lung cancer as well.

A different 2015 review of 10 studies which looked directly at wood dust exposure and lung cancer found a significantly increased risk of lung cancer with wood dust exposure; those who were exposed to wood dust were at least 20 percent more likely to develop the disease.

Since lung cancer is the leading cause of cancer-related deaths in men (and women) and can occur in non-smokers as well as people who smoke, this is very important. In contrast, a slightly reduced risk of lung cancer was noted in people in Nordic countries who were exposed to primarily softwood dust. The conclusion was that there is strong evidence for the association of wood dust with lung cancer, but that this may be dependent on geographic location and the type of wood dust exposure.

Another study out of Canada found the risk of lung cancer related to wood dust exposure was around 40 percent higher than for those not exposed to the dust. The most common occupations linked with exposure were construction work, timber, and furniture making. An important point in this study, however, is that substantial exposure over a lengthy period of time was necessary to increase cancer risk, and there was little risk among those whose cumulative exposure was not substantial. (This may be of some reassurance to those who enjoy woodworking as a hobby.)

Other Medical Conditions Related to Wood Dust Exposure

Wood dust has long been known to lead to medical conditions other than cancer. These include:

  • Skin rashes (dermatitis) - Skin rashes related to wood dust are common and have been found with exposure to dust from over 300 different types of trees. These rashes, itching, and redness can arise due to either irritation of the skin or, instead, from allergic reactions. An HSE information sheet lists some of the specific symptoms noted with different types of trees.
  • Respiratory allergies - Allergic reactions are common with exposure to wood dust and allergic asthma is common. It's important to note that asthma may be a risk factor for lung cancer as well. The best-known reaction is to that of red cedar, to which five percent of workers are allergic. Wood dust is considered one of the top 10 causes of occupational asthma in the U.K. (Learn more about irritant-induced or occupational asthma.)
  • Respiratory symptoms unrelated to allergies - Nasal symptoms, such as itching, dryness, and repeated episodes of sinusitis are linked to wood dust exposure, as well as coughing and wheezing.
  • Decreased lung function - Though noted more with softwoods, exposure to wood dust may result in decreased pulmonary function. In addition, exposure to wood dust can disrupt the cilia, the small hair-like structures in the respiratory tree which work to remove inhaled toxins from the airways.

Recommended Limits for Wood Dust Exposure

Before 1985, there was little direction from the Occupational Safety and Health Review Commission regarding exposure to wood dust. Since that time, a number of different limits have been proposed. OSHA proposed an eight hour limit of 1 mg/m3 for hardwood and 5 mg/m3 for soft wood, though, in the final ruling, an eight-hour exposure limit of 5 mg/m3 was adopted for both. An exception is red cedar wood dust, for which the eight-hour limit is 2.5 mg/m3 due to its potential to cause allergic reactions.

Occupations at Risk of Wood Dust Exposure

What occupations may result in wood dust exposure that could be a lung cancer risk? In determining which jobs carry most risk it's important to think about what jobs result in the formation of wood dust. Some occupations at risk include:

  • Carpentry
  • Pulp and paper mill workers
  • Furniture workers
  • Cabinet makers
  • Sawmill workers

Hazards and Precautions for Those Who Work with Wood Dust

In addition to following the limits for eight-hour exposure to wood dust, there are many things that employers and employees can do to minimize exposure. Many specific activities (such as vacuuming wood dust rather than sweeping) can significantly reduce your exposure. Check out OSHA's information covering potential hazards and possible solutions with regard to wood dust exposure on the job to learn about ways to reduce the amount of wood dust you breathe in at work.

Other Potential Exposures in Wood Working

It's important to simply note that there can be other exposures to toxic substances among those working with wood. Some of the chemicals used, such as some glues, can also be a risk factor for cancer. Make sure to read the Material Data Safety Sheets on all substances you are exposed to at work.

What About Your Woodworking Hobby?

Exposure to wood dust as a hobby doesn't appear to carry the risk of lung cancer. In studies thus far, exposure to wood dust as a hobby was not found to be linked with lung cancer, and even with occupational exposure, the exposure needed to be "cumulative and substantial." That said, always practice good ventilation while working with wood and with any chemicals. Always read labels and follow the recommendations. If a label recommends using gloves or a mask, heed those instructions.

Bottom Line on Wood Dust and Lung Cancer Risk

It can be discouraging as you consider cancer risks with specific exposures. You may catch yourself saying, "Doesn't everything cause cancer?" Yet,learning about these risks, and taking action, doesn't mean that you need to become a fanatic. There are often very simple measures you can take to reduce your risk.

Employers now have guidelines in place which specify the quantity and amount of time that a person may be exposed to wood dust without raising the risk of cancer. That said, it is important for employees to both be aware of these guidelines and follow them, and to speak up if appropriate attention to these limits is not followed in their place of work.

 Whether or not you are exposed to wood dust, take the time to check out these tips for lowering your risk of lung cancer. Lung cancer remains the leading cause of cancer-related deaths for both men and women and though less common, lung cancer in never-smokers is the 6th leading cause of cancer-related deaths in the United States.

Sources:

Alonso-Sardon, M., Chamorro, A., Hernandez-Garcia, I. et al. Association Between Occupational Exposure to Wood Dust and Cancer: A Systematic Review and Meta-Analysis. PLoS One. 2015. 10(7):e0133024.

Centers for Disease Control and Prevention. The National Institute for Occupational Safety and Health (NIOSH). Wood Dust. Updated 09/28/11. https://www.cdc.gov/niosh/pel88/wooddust.html

Hancock, D., Langley, M., Chia, K., Woodman, R., and E. Shanahan. Wood Dust Exposure and Lung Cancer Risk: A Meta-Analysis. Occupational and Environmental Medicine. 2015. 72(12):889-98.

Vallieres, E., Pintos, J., Parent, M., and J. Siemiatycki. Occupational Exposure to Wood Dust and Risk of Lung Cancer in Two Population-Based Case-Control Studies in Montreal, Canada. Environmental Health. 2015. 14:1.

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