That suggests there’s a link between tear gas and “possible issues with oxygenation of blood and possible oxygen deprivation of a heart muscle” that can linger for weeks, Chakhunashvili says. He and his colleagues also surveyed over 300 demonstrators and found that more than a third reported experiencing headaches, eye problems, skin disorders, high blood pressure or psychological trauma more than a month after exposure.

Hassan and her colleagues analyzed survey responses from more than 1,200 people who had been exposed to chemical agents by law enforcement in 2020 and 2021. In 2023, Hassan and her colleagues reported that 83 percent of the exposed individuals experienced uterine cramping, breast tenderness or early or late menstrual bleedings. What’s more, they found that individuals that had been exposed on more than two days were twice as likely to experience an adverse effect as those exposed on one day.

Notably, 10 of the 19 individuals who reported that they were pregnant when exposed reported a subsequent miscarriage — that’s about twice the expected rate of miscarriage.