Some weapons used by the United States military are so powerful, they can pose a threat to the people who fire them — even in training. When weapons are fired, an invisible blast wave travels through the brains of anyone nearby. Exposure to lots of these blasts over time — even low level ones — has been shown to cause brain health problems for service members. If you liked this episode, consider checking out some more episodes on the brain, including its waste system, face blindness and the neuroscience of loneliness. Questions or ideas you want us to consider for a future episode? Email us at shortwave@npr.org. We'd love to hear from you!Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy