Worker Health Study Summaries
Research on long-term exposure
Wood Model Makers
NIOSH studied the health effects of wood model making.
Why the Study Was Done
We did the study because earlier reports strongly suggested that wood model makers had a greater chance of getting colon cancer than other people.
(The colon is the lowest portion of the digestive system. It is also called the large intestine.)
How the Study Was Done
We studied 2,294 men who had worked as model makers at 3 auto companies in the Detroit area. These men worked as model makers between 1940 and 1980.
The study was based on company work records. We did not contact individual workers to do the study.
NIOSH collected air samples in the places where the model makers worked. From this, we estimated the levels of wood dust in the work areas. We also noted which jobs involved exposure to metals and plastics.
This study reports how the health of model makers at the 3 plants compares to white males in the U.S. population.
The study results do not describe an individual’s personal risk for disease.
The NIOSH study found somewhat more colon cancer than we expected when compared to the U.S. population. We expected to find 17 colon cancer deaths. Instead, we found 21. This was a small increase in risk.
When compared to other men in Wayne County, the increase disappeared.
We found no link between colon cancer and how long men had worked as model makers, or how much wood dust they had been exposed to.
The NIOSH study also looked at other causes of death among wood model makers.
The study found slightly more stomach cancer than expected. We expected to find 10 or 11 stomach cancer deaths. Instead, we found 17.
The findings for stomach cancer were stronger than for colon cancer and were less likely due to chance, than the colon cancer deaths.
Our study did not show a link between either colon or stomach cancer and wood dust exposure. Additionally, we were not able to fully measure other exposures that could be related, such as paints, glues, and metals.
Since various materials were used in the model makers’ workplace, we could have missed a possible connection between an exposure to these substances and colon or stomach cancer.
It is also possible that the slight increases in disease were due to personal factors, not model making.
Perhaps non-occupational factors such as eating habits, and personal and family health history were related to the cancers which we found in the NIOSH study.
Previous studies of model makers in the Detroit area had reported excesses of colon cancer, but no excess of stomach cancer.
A 1992 report about West German model makers found an excess of stomach cancer, but not colon cancer.
The NIOSH findings are different from these other studies. We do not know why the studies have different results or which study is correct.
The main risk factor thought to be related to stomach cancer is related to diet. Avoiding pickled, cured, and smoked foods may help prevent stomach cancer.
A diet rich in fresh fruits and vegetables may also help reduce risk for stomach cancer.
There are two main factors thought to be related to colon cancer. One is family history of colon cancer or non-cancer growths in the colon called polyps.
People who have a personal history of polyps or whose relatives had colon cancer or polyps are more likely to get colon cancer.
Another factor is related to diet. Avoiding fatty foods may help to prevent colon cancer. Eating high fiber foods may also help prevent colon cancer.
Screening for Colon Cancer
The National Cancer Institute (NCI) recommends that everyone, regardless of occupation, have a stool blood screening test every 3 – 5 years after age 50. The stool blood test checks the stool for hidden blood which can be a sign of cancer.
NCI also recommends that everyone, regardless of occupation, have a sigmoidoscopy test every 3 to 5 years after age 50.
For the sigmoidoscopy, a doctor uses a hollow, lighted tube to inspect the colon for growths.
(There is no screening test for stomach cancer.)