"That, to me, was where I really had questions because that usually doesn't happen." 

So Asha Hassan and researchers from the U of M and Planned Parenthood 6surveyed people across the country. 

"Anyone who was an adult who had been exposed to tear gas during that time period and who had a 7uterus was eligible to 8participate inthis study." 

Of the more than 1,200 participants, 83% reported 9adverse reproductive health 10outcomes. The top changes were 11cramping and early menstrual 12bleeding. Those with five or more days of exposure experienced 2.6 times more negative reproductive outcomes. 

"This is really something that's 13exploratory and allows us to say yes there's a relationship here between being exposed to tear gas and having these adverse reproductive health outcomes." 

Starting this year, Minneapolis police can only use crowd control tools such as chemical agents in specific situations after high-level authorization. Chief Brian O'Hara said "For many reasons, MPD has made 14significant recent policy changes to ensure a more 15thorough 16consideration of the wellbeing of all involved before 17deploying crowd control weapons such as tear gas." The study has limitations and does not prove a cause and effect. 

"I think it's important also to note that this is a 18snapshot in time."

But Hassan hopes it 19fuels further research in an area that's lacking.