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WEDNESDAY, Aug. 27, 2003 (HealthDayNews) -- Smoking is not the only danger to your lungs.
Exposure to toxins in the workplace may be responsible for 20 percent of the cases -- up to 5 million -- of chronic obstructive pulmonary disease (COPD) in the United States, a new study says. COPD is a category that includes emphysema, chronic bronchitis and other respiratory illnesses.
While smoking accounts for the vast majority (about 80 percent) of the 16 million diagnosed cases of COPD, clearly other factors are also involved.
"There are people who do not smoke who get these disease, so the question is what else is contributing to this condition?" says study author Laura Trupin, an epidemiologist with the University of California San Francisco School of Medicine, whose findings appear in the September issue of the European Respiratory Journal. "This study attempted to clarify and quantity what proportion could be considered contributed by occupational exposures."
People who smoked and had exposure to toxic fumes, vapors or dust were at an even higher risk of developing COPD.
People with COPD have an obstruction of their airways and, as a result, difficulty breathing. It is the fourth highest cause of death in the United States and kills more than 100,000 people every year. The disease kills 3 million people each year around the world.
So-called "dusty trades" have been associated with chronic bronchitis for more than a century. In particular, miners are known to be particularly susceptible to lung disease.
To assess the impact of workplace toxins, the study team randomly telephoned more than 2,000 people aged 55 to 75 and asked them questions about their health and their work histories. This age bracket is when the incidence of COPD generally peaks.
Risk factors were divided into three categories: vapors, gases and smoke associated with work in blast furnaces and foundries; work with diesel engines and firefighting; mining and metalworking, which involve exposure to non-organic dust and smoke; and farmers, bakers, and textile workers who are primarily exposed to organic dust.
While only one-third of those people with no respiratory disease reported exposure to airborne toxins in the workplace, more than half of the people with COPD reported such exposure.
Occupational exposure to fumes, dust, vapors and the like doubled the risk of COPD.
The danger was even higher for smokers who had breathed in workplace toxins. "There appears to be an interaction if you're a smoker and you have occupational exposure," Trupin says. "Your risk of COPD increases vastly over any of the other of the two exposures."
"The study is important because it brings together evidence that has been out there," says Dr. Norman Edelman, a consultant for scientific affairs for the American Lung Association. "What's surprising is the estimate that 20 percent of COPD could be attributed to toxic inhalants in the workplace. That's a lot. The other thing that falls out of the study that is important is the synergism between smoking and toxic inhalants. If you're exposed and you smoke, the risk of COPD is greater."
The evidence points to the need for greater regulation of the workplace, Edelman says. "What I hope [the study] will do is heighten our awareness of the level of the problem and get much better regulation of the environment of the workplace," he says. "This is a huge health burden."
Also, Trupin adds, "physicians need to hold in their mind that occupational history is an important part of people's health history, that there may be other red flags besides cigarette smoke."
More information
For more on COPD, visit the American Lung Association. The U.S. Centers for Disease Control and Prevention has more on work-related lung disease.
