A new study surveying people exposed to tear gas during protests last year in Portland found that nearly 900 respondents reported abnormal menstruation, including increased bleeding that persisted for days.
BMC Public Health published the first peer-reviewed study on the subject, which was based on a survey of over 2,200 anonymous people, The Guardian reports. In addition to those who reported increased and irregular bleeding after being exposed to tear gas, other people reported headaches, nausea, and diarrhea.
The study backs up the claims of protestors across the country who have reported menstruating after being tear gassed by police officers. “It’s like they’re testing it on us,” a 24-year-old woman told Oregon Public Broadcasting in a report on periods and tear gas last year, after getting her period five times between June 2 and July 5. Trans men taking testosterone also reported having irregular bleeding after being tear-gassed at protests.
Tear gas has also previously been linked to potentially inducing miscarriage. In 2011, the Chilean government suspended the use of tear gas on protestors after a University of Chile study found it could cause miscarriages. In 1988, the U.N. reported that tear gas fired by Israeli soldiers caused “dozens of miscarriages” in Palestinians.
If you’re wondering how on Earth are we just now officially establishing a link between teargas and abnormal menstruation, that’s because tear gas has been primarily tested on men, The Guardian reports.