Fractured skulls. Blindness. Traumatic brain injury. This is among the damage caused by less-lethal weapons during protests following the deaths of George Floyd and Daunte Wright.

University of Minnesota Medical School faculty and students couldn’t help but notice the severity of the injuries they saw both on the news and in the hospitals.

So they dug into the data to find out just how common those injuries were.

One faculty and student group found that in the three weeks immediately after Floyd was murdered by a police officer, at least 89 people reported protest-related injuries from projectiles such as rubber bullets or chemical irritants such as tear gas. (The study included patients seen at hospitals and clinics in the M Health Fairview and Hennepin Healthcare systems—and, of course, only those who sought medical care for their injuries.) 

Seven patients needed surgery as a result of their injuries, 10 suffered eye trauma from projectiles, and 16 patients sustained traumatic brain injuries. About 40% of those injured by projectiles were hit in the head, neck, or face.

Another study, conducted by five Medical School doctoral students, called attention to the lack of regulation and unknown long-term health effects of tear gas, though it’s commonly used by law enforcement agencies in the United States to help control crowds.

“Most tear gases attack the upper respiratory tract, so using them during a respiratory pandemic could increase the spread of disease, making them more dangerous,” says Roman Tyshynsky, one of the graduate student investigators.

Both groups pointed out that, while these tactics are less lethal than some alternatives, they aren’t without harm, and implored police to find better ways to regulate crowds.