A new study is lending credence to widespread claims from protesters that tear gas messed with their periods. Dozens of protesters told media outlets about period irregularities, which they blamed on tear gas exposure, following protests across the country last summer. Now, those claims take center stage in an anonymous survey of 2,257 adults exposed to tear gas in Portland, Ore., between July 30 and Aug. 20. More than half of the 1,650 respondents who menstruate described some kind of period irregularity after exposure. This included increased cramping (36.6%), unusual spotting (27.8%), increased bleeding (23.6%), and more days of bleeding than expected (18.9%), reports Oregon Public Broadcasting. Others reported bad headaches, diarrhea, nausea, and mental health issues. Some said their health issues lasted for weeks or months.
People who reported more frequent exposure described more serious period disruptions, study author Britta Torgrimson-Ojerio of the Kaiser Permanente Center for Health Research says, per the Guardian. It's not known whether the chemicals in tear gas, mostly tested on male police officers and soldiers, can affect the endocrine system, and, in turn, menstruation, as high levels of the stress hormone cortisol can. But Chile's government banned the use of CS gas, one of the most common forms of tear gas, on protesters in 2011 after researchers found a possible link to miscarriages, reports Newsweek. Portland police were banned from using CS gas in most situations in September, per OPB. While the study published in the BMC Public Health journal doesn't point to a cause, it does show period irregularity issues after tear gas exposure are "widespread and widely reported," Torgrimson-Ojerio tells OPB. (More tear gas stories.)