Retained dust found in lungs of deployed military personnel

Researchers found increased amounts of retained dust in the lung tissue of previously deployed military personnel with confirmed lung injury, according to a presenter at the 2022 Geological Society of America Meeting.

“We found, generally speaking, the military deployers did have more retained dust in their lungs per cubic centimeter of tissue that we looked at compared to the controls,” Heather Lowers, MS, research geologist at the U.S. Geological Survey, said in a press release from The Geological Society of America. “And the particles generally seemed to be a smaller size as well, compared to the dust that was retained in the control group.”

Because of the prevalence of persistent respiratory symptoms such as asthma and bronchiolitis that develop among miliary personnel deployed to Southwest Asia and Afghanistan, and evidence suggesting that desert topsoil and airborne dust from Iraq and Afghanistan can lead to lung inflammation and injury, researchers at National Jewish Health established a clinic to evaluate previously deployed military personnel with symptoms of lung injury.

Lowers and colleagues analyzed lung biopsy reports for in situ lung particulate matter — including silica, aluminosilicates, other silicates, metals, carbonaceous or other — from 24 deployed military personnel with small airway and distal lung abnormalities who presented to the clinic, as well as from 11 normal donated lung specimens that acted as controls.

Overall, researchers observed that compared with the age- and smoking-matched controls, those in the deployed group had higher relative particle loads of silica, aluminosilicates and other silicates, but these differences were also not statistically significant.

Specifically, the deployed group had greater lung silica burden when they reported no/low sandstorm exposure or medium/high exposure. However, researchers observed no significant difference between both groups for aluminosilicates burden.

“In general, even when there are no dust storms, soldiers work in a pretty dusty environment,” Lowers said. “So we were looking at a culmination of all that would have been inhaled during their deployment. Even driving a truck across the desert floor, you’re going to kick up dust and breathe it in.”

Those deployed also had shorter mean particle length and area, but again researchers reported in the abstract that the differences between the groups did not reach significance.

In the control group, researchers found higher loads of carbonaceous, metals and “other phases,” with only the latter being significantly higher when compared with the deployed group (P = .04).

Lowers said in the press release that future studies on this subject require more samples.

“One of the challenges I’ve learned working with human subjects is that it’s very difficult to get enough people enrolled in these studies,” Lowers said. “So, while we’re generally seeing differences between the controls and the deployers, the number of samples are limited.”

Reference:

Previously deployed military personal show retained dust in lungs. https://www.geosociety.org/GSA/News/pr/2022/22-56.aspx. Published Oct. 7, 2022. Accessed Oct. 20, 2022.