Coal fire fine exposure increases COPD risk in nonsmokers

Exposure to high concentrations of fine particulate matter from a coal mine fire over a 6-week period was associated with an increased risk for COPD in nonsmokers nearly 4 years later, researchers reported.

Researchers evaluated 346 adults who were exposed to high concentrations of fine particulate matter during the Hazelwood open-cut coal mine fire in Australia that burned for 6 weeks in 2014 and 173 adults who were not exposed to the fire. The research was part of the longitudinal Respiratory Stream of the Hazelwood Health Study. All participants underwent spirometry and responded to validated respiratory questionnaires 3.5 to 4 years after the coal mine fire to assess individual-level fine particulate matter (PM_2.5) exposure related to the fire.

“We found that nonsmokers exposed to smoke from the coal mine fire were 4 years later more likely to have spirometry consistent with COPD,” Michael J. Abramson, MD, professor of clinical epidemiology in the School of Public Health and Preventive Medicine at Monash University in Melbourne, Australia, told Healio. “All participants who were exposed to the smoke were more likely to report chest tightness and cough than those who were not exposed.”

One-hundred nine participants had low exposure to PM_2.5 from the fire (mean age, 54.7 years; 46% men), 113 had medium exposure (mean age, 54.5 years; 43% men) and 124 had high exposure (mean age, 56.7 years; 56% men).

Every 10 µg/m³ increase in mean PM_2.5 exposure was associated with a 69% increase in odds of spirometry consistent with COPD in those who did not smoke, as well as increased odds of chest tightness (OR = 1.3; 95% CI, 1.03-1.64) and chronic cough (OR = 1.24; 95% CI, 1.02-1.51) in the previous year among all participants, according to the results.

In addition, increments in mean PM_2.5 exposure were associated with increased odds of chronic cough in the previous year in those who reported current smoking (OR = 2.13; 95% CI, 1.24-3.65).

The results were published in Annals of the American Thoracic Society.

“The Hazelwood Health Study has been funded for a further 3 years. We plan to repeat the respiratory function testing next year,” Abramson said. “This will enable us to get a handle on whether there is an increased rate of decline in lung function among exposed participants. This would mean that they are at a greater risk of COPD in the future.”

For more information:

Michael J. Abramson, MD, can be reached at michael.abramson@monash.edu.