Occupational hazards, which include inhaling vapors, gas, dust or fumes at work, may be responsible for a number of noncancerous lung diseases, according to a joint American Thoracic Society and European Respiratory Society statement.

“The role of occupational factors in most lung disease is underrecognized,” Paul D. Blanc, MD, MSPH, chief of the division of occupational and environmental medicine at the University of California, San Francisco, and lead author of the statement, said in a press release. “Failure to appreciate the importance of work-related factors in such conditions impedes diagnosis, treatment and, most importantly of all, prevention of further disease.

Occupational exposure and burden of disease

Blanc, who co-led a task force charged with drafting the statement, and colleagues conducted a literature review of studies evaluating the relationship between occupational hazards and major nonmalignant respiratory diseases, such as airway diseases, interstitial fibrosis, hypersensitivity pneumonitis, other noninfectious granulomatous lung disease, including sarcoidosis, and selected respiratory infections.

They then estimated the occupational population attributable fraction for those conditions that had sufficient population-based studies to yield pooled estimates. For other conditions, the occupational burden of disease was estimated based on attribution in case series, including incidence rate ratios, or attributable fraction within an exposed group.

The task force excluded cancer of the lung and pleura, as estimates have been previously reported, and estimates of asbestosis, silicosis and coal workers’ pneumoconiosis because these conditions are entirely work-related.

According to data, the estimated occupational burden of various lung diseases were:

• 16% for asthma;
• 14% for COPD;
• 13% for chronic bronchitis;
• 26% for idiopathic pulmonary fibrosis;
• 19% for hypersensitivity pneumonitis;
• 30% for sarcoidosis and other granulomatous disease;
• 29% for pulmonary alveolar proteinosis;
• 10% for community-acquired pneumonia in working-age adults; and
• 2% for tuberculosis in silica dust-exposed workers.

“This comprehensive literature review and analysis of nonmalignant respiratory disease demonstrates a substantial occupational burden for multiple respiratory conditions not typically considered potentially work-related,” Blanc and colleagues wrote in the statement.

For instance, although estimates for asthma, COPD and chronic bronchitis have been previously documented, other estimates, including those for IPF and community-acquired pneumonia in working-age adults, highlights a “newly appreciated magnitude of risk,” Blanc said in the press release.

Future implications

The study was not without limitations, according to Blanc and colleagues. Specifically, studies on asthma were primarily limited to developed economic settings. Furthermore, the studies included in the analysis were extremely heterogeneous, precluding a formal systematic review, and the task force also chose not to formally grade publication quality. There was also potential for differences in risk due to the nature of exposure and pathogenesis of the disease. Finally, the statement authors noted that the data did not lend themselves to analysis of disability-adjusted life-years, which may have provided more information on the health impact of different work exposures.