Members of the armed forces who are regularly firing small arms might be at increased risk for respiratory issues, according to researchers from Oslo University Hospital and the Norwegian Defence Research Establishment. Study results were presented earlier this week at the 2013 European Respiratory Society Annual Congress, in Barcelona, Spain.

For the study, 55 healthy, non-smoking men from the Norwegian Armed Forces underwent spirometry testing in a controlled environment to gauge exposure levels before, shortly after, and 24 hours after shooting. Researchers tested the exposure to three different types of ammunition used in an assault rifle: one leaded and two lead-free.

Researchers found all participants’ lung function declined by a mean average of 5% at 1 hour after shooting and by 7% at 24 hours after. There were no significant differences in the types of ammunition used.

“These lung function changes are comparable to the effects caused by other occupational risk factors, such as organic dusts in farming and cotton workers,” noted Anne-Katrine Borander, lead author of the study from the Oslo University Hospital. “Although we noticed this decline for all types of ammunition, further research can now be undertaken to look at specific exposure components to help design better ammunition, and to continue implementation of other measures for avoiding these effects.”