Risk for exposure-related respiratory diseases varies among US military personnel
DALLAS — Risk for respiratory illnesses related to complex, poorly characterized inhalation exposures is a concern for U.S. military personnel who have been deployed to Iraq and Afghanistan; however, it is not clear which workers are at risk for exposure-related respiratory diseases. A new study presented at the American Thoracic Society International Conference utilized military occupational specialty codes to identify high-exposure jobs and those at greatest risk for inhalational exposures.
Cecile S. Rose, MD, and colleagues investigated the utility of military occupational specialty (MOS) codes in identifying post-9/11 deployers who may be most at risk from inhalation exposures using a respiratory exposure matrix. Deployers were primarily in Iraq and Afghanistan.
“Our goal was to see if those with exposure intensity MOS might be prioritized for pre-deployment lung function testing and/or training for hazard exposure conditions in the theatre,” Rose said during a presentation at the ATS International Conference.
The respiratory hazard exposure matrix was based on the frequency, proximity, likelihood and intensity of the five most commonly reported inhalation exposures: diesel exhaust, sandstorms, smoke from burn pits, combat dust, and vapor, dust, gas and fume (VDGF) exposures.
“We developed an expert panel that included three occupational pulmonologists and four previously deployed military physicians,” Rose said. “[They] looked at the descriptions of the MOS codes that were available on the Department of Defense website and they scored all of the Army and Marine MOS using our respiratory hazard exposure matrix.”
Overall, the panel reviewed 228 Army MOS codes and 37 Marine codes. The researchers also analyzed questionnaire data from symptomatic deployers for comparison; data were available for 48 Army codes and six Marine codes from 81 deployers, with an average exposure duration of 20 months in theater and two deployments, Rose said.
Across all MOS codes, exposure to diesel exhaust and sandstorms were scored highest by the panel, thus with the greatest respiratory risk. All respiratory hazard exposures were scored significantly higher for combat-related jobs compared with noncombat-related jobs, with the exception of VDGF.
“Combat MOS codes were linked to the highest mean respiratory hazard exposure intensities and to likelihood of having undergone clinical evaluation for respiratory symptoms,” Rose said.
The researchers reported no difference in rated exposures for Army vs. Marine MOS.
A significant but weak association emerged between the panel-rated hazard scores and deployer-reported exposure for diesel exhaust and combat dust. The researchers observed poor correlations between the other respiratory hazard exposure variables.
Symptomatic deployers reported significantly higher exposure intensity than was scored by the panel, Rose said.
Eighteen percent (n = 48) of MOS codes faced the most intense respiratory hazard exposures, as rated by the expert panel.
Jobs with the highest overall exposures by panel rating included:
- artillery maintenance;
- combat engineering;
- combat medicine;
- motor transport;
- ordinance disposal;
- special forces;
- utility maintenance/repair; and
- vehicle and aircraft maintenance.
Jobs with the lowest overall exposure by panel rating included noncombat medical, logistics, geospatial engineering and chaplain, among others.
“Military deployment exposures may be related to variables such as deployment location, timing, season and job duties during deployment that are not reflected in MOS codes,” Rose said.
A limitation of the study as an epidemiological tool for predicting respiratory risk is that specific MOS codes do not reliability predict inhalation exposures in theater, according to the researchers.
“We think that our findings suggest ... that pre-deployment lung function testing might be reasonable to target deployers who are in combat-specific MOS codes,” Rose said. “But we also found that an MOS code, by itself, is insufficient terms of predicting respiratory hazard.” – by Scott Buzby
Rose CS. Abstract 4254. Presented at: American Thoracic Society International Conference; May 17-22, 2019; Dallas.
Disclosure: Rose reports no relevant financial disclosures.