Careers that tend to expose people to repeated low-level shockwaves are associated with a slightly higher risk of clinically documented anger, aggression, and violence, new research from University of Utah Health has found.
The study used AI to compare health records from 10,000 veterans and found that those who had served in roles with higher risk of blast exposure were more likely to have raised concerns related to anger to their doctor. Importantly, anger was rare across both groups, with less than 3% of clinical notes mentioning anger, aggression, or violence.
"Although the effect was moderate, our findings do suggest that long-term occupational blast exposure is a risk factor for anger, even independently of other military exposures," says Eamonn Kennedy, PhD, research assistant professor of epidemiology at U of U Health, research health science specialist at the VA Salt Lake City Health Care System, and the first author on the study.
The findings suggest that chronic low-level blast exposure is one of many interwoven factors that can affect veterans' health, demonstrating a need to develop risk-reduction strategies to keep veterans healthy.
High-blast-exposure careers associated with later anger concerns
The study found that 17% of veterans whose jobs were associated with a higher risk of blast exposure had anger and aggression later documented at any point in their clinical records, compared to 12% of veterans whose jobs had a low risk of blast exposure.
Jobs associated with higher blast exposure, such as infantry, artillery, and weapons instructors, involve firing heavy weapons or being near explosions, which expose people to shockwaves that generally aren't strong enough to cause a concussion or other immediate trauma. But increasing evidence shows even repeated low-level blasts could have long-term effects on health.
The research team used a secure, offline AI system to categorize the clinical notes of 5,000 veterans who had served in high-exposure roles and 5,000 who had served in low-exposure roles for language indicating anger or frustration, confirming the results by spot-checking AI classifications by hand.
Results suggest ways to reduce risk and keep people healthy
While serving in roles with a higher risk of blast exposure is linked to higher chances of anger and aggression, the results suggest that many other factors affect risk. For instance, people who served in high-blast-exposure jobs are more likely to experience post-traumatic stress disorder (PTSD), which can also lead to symptoms of anger. But even when the researchers controlled for PTSD and other contributing factors, blast exposure had a small but meaningful effect on risk of anger, suggesting that reducing low-intensity blast exposure could help keep veterans healthy.
"Occupational exposure to low-level blasts exists within a network of numerous interplaying exposures and risks, stress, trauma, physical injury, psychiatric illness, and so on," Kennedy says. "But for people who are experiencing challenges, occupational blast exposure can be an additional burden."
By demonstrating a link between blast exposure and mental health, the results open the door to risk-reduction strategies.
"Occupational blast exposure is largely modifiable because it typically occurs during training, where we have very, very controlled situations, and that gives us access for reducing harm," Kennedy says. "There's a balance where people can still be trained and prepared to do the mission, but with less risk for these negative health consequences."
