NIOSH Update: New Leads for Lung Disease Prevention Offered in NIOSH Study That Charts Areas of High Prevalence

A new study by the U.S. Centers for Disease Control and Prevention's (CDC) National Institute for Occupational Safety and Health (NIOSH), drawing from a representative sample of the U.S. adult population, identifies industries and occupations with a higher-than-expected prevalence of chronic obstructive lung disease (COPD). The study also estimates the fraction of cases with COPD attributable to work in such "at-risk" industries and occupations. To NIOSH's knowledge, this was the first study that has developed such an estimate from U.S. population-based data.

NIOSH noted that the purpose of the study was to stimulate questions that will lead to further, focused research in this critical area of public health. In so doing, the findings provide scientists, health professionals, and others with new leads for research and interventions to reduce the occurrence of chronic obstructive lung disease, which includes chronic bronchitis and emphysema and is the fourth leading cause of death in the general U.S. population.

Results included these:

• The study found that 19 percent of COPD cases found in the U.S. population can be attributable to work in industries that pose a risk for these illnesses. In persons who never smoked, the proportion was even higher (31 percent). This indicates a substantial potential to prevent COPD through control of respiratory health hazards in the workplace.
  
• Consistent with earlier industry-specific research, the study found an increased risk for COPD in the rubber, plastics and leather manufacturing industries, the textile mill products manufacturing industry, the food products manufacturing industry, agriculture, and construction. The study also suggests an increased risk in other industries (such as utilities and office building services) that have not previously been associated with a risk for COPD.
  
• Consistent with past studies and with known job-related exposures in specific industries and occupations, the study found that COPD was substantially more prevalent in blue-collar industry sectors than in white-collar industry sectors. The study found more than a two-fold increased prevalence (in comparison with white-collar workers combined across all industries) in workers in rubber, plastic, and leather manufacturing; utilities; office building services; textile mill products manufacturing; armed forces; and food products manufacturing. Similarly, an increased prevalence of COPD was observed among freight stock and material handlers, vehicle mechanics, and in non-smokers in several occupational categories: records processing and distribution clerks, machine operators, and construction workers.

More than 20 million workers in the U.S. are exposed to gases, vapors, fumes, and dusts that can cause COPD. The findings suggest that the burden of COPD, particularly among the blue-collar industrial workforce, can be reduced or prevented through measures to reduce hazardous occupational exposures, and through effective workplace pulmonary function screening for timely identification and treatment of COPD in early stages. Reducing the burden of work-related COPD would also significantly reduce the overall burden of COPD in the U.S. adult population. Epidemiological research is needed to confirm the association of COPD with the industries that were not previously identified as being at-risk industries, and to identify causal risk factors.

The study was published in the October 15, 2002, issue of the American Journal of Epidemiology. It was based on a sample of 9,823 individuals, 30 to 75 years old, drawn from the Third National Health and Nutrition Examination Survey, which was conducted by CDC's National Center for Health Statistics from 1988 to 1994. The methods of the study took into account various potential confounding factors such as age, sex, race/ethnic group, education, income, and smoking. However, because of limitations in its data and approach, the study did not identify all industries and occupations where exposures are hazardous; for example, mining was not identified as a high-risk industry.

COPD is included among several priority areas identified by NIOSH and its partners under the National Occupational Research Agenda (NORA) for research that will do the most to protect workers from job-related illnesses and injuries. NORA was developed and implemented by NIOSH and diverse outside partners with input and review by more than 500 individuals and organizations.

For further information on NIOSH research pertaining to COPD and other job-related respiratory diseases, call toll-free 1-800-NIOSH (1-800-356-4674) or visit the NIOSH web page at www.cdc.gov/niosh. For more information on NORA, visit www.cdc.gov/niosh/nora.